pax_global_header00006660000000000000000000000064152152660610014516gustar00rootroot0000000000000052 comment=35c67cb7f2dc697ed0c7c06400fcf29a8a521d7d nvim-mini-mini.test-6f129de/000077500000000000000000000000001521526606100157535ustar00rootroot00000000000000nvim-mini-mini.test-6f129de/LICENSE000066400000000000000000000020621521526606100167600ustar00rootroot00000000000000MIT License Copyright (c) 2021 Evgeni Chasnovski Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. nvim-mini-mini.test-6f129de/README.md000066400000000000000000000152601521526606100172360ustar00rootroot00000000000000

mini.test

### Write and use extensive Neovim plugin tests - Supports hierarchical tests, hooks, parametrization, filtering (like from current file or cursor position), screen tests, "busted-style" emulation, customizable reporters, and more. - Designed to be used with provided wrapper for managing child Neovim processes. See more details in [Features](#features) and [Documentation](doc/mini-test.txt). For more hands-on introduction based on examples, see [TESTING.md](https://nvim-mini.org/mini.nvim/TESTING). For more in-depth usage see ['mini.nvim' tests](https://github.com/nvim-mini/mini.nvim/tree/main/tests). --- > [!NOTE] > This was previously hosted at a personal `echasnovski` GitHub account. It was transferred to a dedicated organization to improve long term project stability. See more details [here](https://github.com/nvim-mini/mini.nvim/discussions/1970). ⦿ This is a part of [mini.nvim](https://nvim-mini.org/mini.nvim) library. Please use [this link](https://nvim-mini.org/mini.nvim/readmes/mini-test) if you want to mention this module. ⦿ All contributions (issues, pull requests, discussions, etc.) are done inside of 'mini.nvim'. ⦿ See [whole library documentation](https://nvim-mini.org/mini.nvim/doc/mini-nvim) to learn about general design principles, disable/configuration recipes, and more. --- If you want to help this project grow but don't know where to start, check out [contributing guides of 'mini.nvim'](https://nvim-mini.org/mini.nvim/CONTRIBUTING) or leave a Github star for 'mini.nvim' project and/or any its standalone Git repositories. ## Demo https://user-images.githubusercontent.com/24854248/175773105-f33cd3bb-6f62-4a61-95b1-b175e11905bb.mp4 ## Features - Test action is defined as a named callable entry of a table. - Helper for creating child Neovim process which is designed to be used in tests (including taking and verifying screenshots). See help for `MiniTest.new_child_neovim()` and `MiniTest.expect.reference_screenshot()`. - Hierarchical organization of tests with custom hooks, parametrization, and user data. See help for `MiniTest.new_set()`. - Emulation of [Olivine-Labs/busted](https://github.com/Olivine-Labs/busted) interface (`describe`, `it`, etc.). - Predefined small yet usable set of expectations (`assert`-like functions). See help for `MiniTest.expect`. - Customizable definition of what files should be tested. - Test case filtering. There are predefined wrappers for testing a file (`MiniTest.run_file()`) and case at a location like current cursor position (`MiniTest.run_at_location()`). - Customizable reporter of output results. There are two predefined ones: - `MiniTest.gen_reporter.buffer()` for interactive usage. - `MiniTest.gen_reporter.stdout()` for headless Neovim. - Customizable project specific testing script. - Works on Unix (Linux, MacOS, etc.) and Windows. ## Installation This plugin can be installed as part of 'mini.nvim' library (**recommended**) or as a standalone Git repository. There are two branches to install from: - `main` (default, **recommended**) will have latest development version of plugin. All changes since last stable release should be perceived as being in beta testing phase (meaning they already passed alpha-testing and are moderately settled). - `stable` will be updated only upon releases with code tested during public beta-testing phase in `main` branch. Here are code snippets for some common installation methods (use only one):
(Recommended) With vim.pack (on Neovim 0.12 and newer) **Full library** Follow ['mini.nvim' installation](https://nvim-mini.org/mini.nvim#installation). **Standalone plugin** Main branch: ```lua vim.pack.add({ 'https://github.com/nvim-mini/mini.test' }) ``` Stable branch: ```lua vim.pack.add({ { src = 'https://github.com/nvim-mini/mini.test', version = 'stable' }, }) ```
With mini.deps (before Neovim 0.12) **Full library** Follow [recommended 'mini.deps' installation](https://nvim-mini.org/mini.nvim/readmes/mini-deps#installation). **Standalone plugin**: Main branch: ```lua add('nvim-mini/mini.test') ``` Stable branch: ```lua add({ source = 'nvim-mini/mini.test', checkout = 'stable' }) ```
With folke/lazy.nvim **Full library** Follow ['mini.nvim' installation](https://nvim-mini.org/mini.nvim#installation). **Standalone plugin** Main branch: ```lua { 'nvim-mini/mini.test', version = false }, ``` Stable branch: ```lua { 'nvim-mini/mini.test', version = '*' }, ```
**Important**: don't forget to call `require('mini.test').setup()` to enable its functionality. **Note**: if you are on Windows, there might be problems with too long file paths (like `error: unable to create file : Filename too long`). Try doing one of the following: - Enable corresponding git global config value: `git config --system core.longpaths true`. Then try to reinstall. - Install plugin in other place with shorter path. ## Default config ```lua -- No need to copy this inside `setup()`. Will be used automatically. { -- Options for collection of test cases. See `:h MiniTest.collect()`. collect = { -- Temporarily emulate functions from 'busted' testing framework -- (`describe`, `it`, `before_each`, `after_each`, and more) emulate_busted = true, -- Function returning array of file paths to be collected. -- Default: all Lua files in 'tests' directory starting with 'test_'. find_files = function() return vim.fn.globpath('tests', '**/test_*.lua', true, true) end, -- Predicate function indicating if test case should be executed filter_cases = function(case) return true end, }, -- Options for execution of test cases. See `:h MiniTest.execute()`. execute = { -- Table with callable fields `start()`, `update()`, and `finish()` reporter = nil, -- Whether to stop execution after first error stop_on_error = false, }, -- Path (relative to current directory) to script which handles project -- specific test running script_path = 'scripts/minitest.lua', -- Whether to disable showing non-error feedback silent = false, } ``` ## Similar plugins - [nvim-lua/plenary.nvim](https://github.com/nvim-lua/plenary.nvim) ('test_harness', 'busted', 'luassert' modules) nvim-mini-mini.test-6f129de/doc/000077500000000000000000000000001521526606100165205ustar00rootroot00000000000000nvim-mini-mini.test-6f129de/doc/mini-test.txt000066400000000000000000001254641521526606100212060ustar00rootroot00000000000000*mini.test* Test Neovim plugins MIT License Copyright (c) 2022 Evgeni Chasnovski ------------------------------------------------------------------------------ *MiniTest* Features: - Test action is defined as a named callable entry of a table. - Helper for creating child Neovim process which is designed to be used in tests (including taking and verifying screenshots). See |MiniTest.new_child_neovim()| and |MiniTest.expect.reference_screenshot()|. - Hierarchical organization of tests with custom hooks, parametrization, and user data. See |MiniTest.new_set()|. - Emulation of [lunarmodules/busted](https://github.com/lunarmodules/busted) interface (`describe`, `it`, etc.). - Predefined small yet usable set of expectations (`assert`-like functions). See |MiniTest.expect|. - Customizable definition of what files should be tested. - Test case filtering. There are predefined wrappers for testing a file (|MiniTest.run_file()|) and case at a location like current cursor position (|MiniTest.run_at_location()|). - Customizable reporter of output results. There are two predefined ones: - |MiniTest.gen_reporter.buffer()| for interactive usage. - |MiniTest.gen_reporter.stdout()| for headless Neovim. - Customizable project specific testing script. - Works on Unix (Linux, MacOS, etc.) and Windows. What it doesn't support: - Parallel execution. Due to idea of limiting implementation complexity. - Mocks, stubs, etc. Use child Neovim process and manually override what is needed. Reset child process it afterwards. - "Overly specific" expectations. Tests for (no) equality and (absence of) errors usually cover most of the needs. Adding new expectations is a subject to weighing its usefulness against additional implementation complexity. Use |MiniTest.new_expectation()| to create custom ones. For more information see: - `TESTING.md` file for a hands-on introduction based on examples. - Code of this plugin's tests. Consider it to be an example of intended way to use |mini.test| for test organization and creation. # Workflow ~ - Organize tests in separate files. Each test file should return a test set (explicitly or implicitly by using "busted" style functions). - Write test actions as callable entries of test set. Use child process inside test actions (see |MiniTest.new_child_neovim()|) and builtin expectations (see |MiniTest.expect|). - Run tests. This does two steps: - Collect. This creates single hierarchical test set, flattens into array of test cases (see |MiniTest-test-case|) while expanding with parametrization, and possibly filters them. - Execute. This safely calls hooks and main test actions in specified order while allowing reporting progress in asynchronous fashion. Detected errors means test case fail; otherwise - pass. # Setup ~ This module needs a setup with `require('mini.test').setup({})` (replace `{}` with your `config` table). It will create global Lua table `MiniTest` which you can use for scripting or manually (with `:lua MiniTest.*`). See |MiniTest.config| for available config settings. You can override runtime config settings locally to buffer inside `vim.b.minitest_config` which should have same structure as `MiniTest.config`. See |mini.nvim-buffer-local-config| for more details. To stop module from showing non-error feedback, set `config.silent = true`. # Comparisons ~ - Testing infrastructure from [nvim-lua/plenary.nvim](https://github.com/nvim-lua/plenary.nvim): - Executes each file in separate headless Neovim process with customizable `init.vim` file. While |mini.test| executes everything in current Neovim process encouraging writing tests with help of manually managed child Neovim process (see |MiniTest.new_child_neovim()|). - Tests are expected to be written with embedded simplified versions of `lunarmodules/busted` and `lunarmodules/luassert`. While |mini.test| uses concepts of test set (see |MiniTest.new_set()|) and test case (see |MiniTest-test-case|). It also can emulate bigger part of "busted" framework. - Has single way of reporting progress (shows result after every case without summary). While |mini.test| can have customized reporters with defaults for interactive and headless usage (provide more compact and user-friendly summaries). - Allows parallel execution, while |mini.test| does not. - Allows making mocks, stubs, and spies, while |mini.test| does not in favor of manually overwriting functionality in child Neovim process. Although |mini.test| supports emulation of "busted style" testing, it will be more stable to use its designed approach of defining tests (with `MiniTest.new_set()` and explicit table fields). Couple of reasons: - "Busted" syntax doesn't support full capabilities offered by |mini.test|. Mainly it is about parametrization and supplying user data to test sets. - It is an emulation, not full support. So some subtle things might not work the way you expect. Some hints for converting from `plenary.nvim` tests to |mini.test|: - Rename files from `***_spec.lua` to `test_***.lua` and put them in "tests" directory. - Replace `assert` calls with |mini.test| expectations. See |MiniTest.expect|. - Create main test set `T = MiniTest.new_set()` and eventually return it. - Make new sets (|MiniTest.new_set()|) from `describe` blocks. Convert `before_each()` and `after_each` to `pre_case` and `post_case` hooks. - Make test cases from `it` blocks. # Highlight groups ~ *MiniTest-hl-groups* - `MiniTestEmphasis` - emphasis highlighting. By default it is a bold text. - `MiniTestFail` - highlighting of failed cases. By default it is a bold text with `vim.g.terminal_color_1` color (red). - `MiniTestPass` - highlighting of passed cases. By default it is a bold text with `vim.g.terminal_color_2` color (green). To change any highlight group, set it directly with |nvim_set_hl()|. # Disabling ~ To disable, set `vim.g.minitest_disable` (globally) or `vim.b.minitest_disable` (for a buffer) to `true`. Considering high number of different scenarios and customization intentions, writing exact rules for disabling module's functionality is left to user. See |mini.nvim-disabling-recipes| for common recipes. ------------------------------------------------------------------------------ *MiniTest.setup()* `MiniTest.setup`({config}) Module setup Parameters ~ {config} `(table|nil)` Module config table. See |MiniTest.config|. Usage ~ >lua require('mini.test').setup() -- use default config -- OR require('mini.test').setup({}) -- replace {} with your config table < ------------------------------------------------------------------------------ *MiniTest.config* `MiniTest.config` Defaults ~ >lua MiniTest.config = { -- Options for collection of test cases. See `:h MiniTest.collect()`. collect = { -- Temporarily emulate functions from 'busted' testing framework -- (`describe`, `it`, `before_each`, `after_each`, and more) emulate_busted = true, -- Function returning array of file paths to be collected. -- Default: all Lua files in 'tests' directory starting with 'test_'. find_files = function() return vim.fn.globpath('tests', '**/test_*.lua', true, true) end, -- Predicate function indicating if test case should be executed filter_cases = function(case) return true end, }, -- Options for execution of test cases. See `:h MiniTest.execute()`. execute = { -- Table with callable fields `start()`, `update()`, and `finish()` reporter = nil, -- Whether to stop execution after first error stop_on_error = false, }, -- Path (relative to current directory) to script which handles project -- specific test running script_path = 'scripts/minitest.lua', -- Whether to disable showing non-error feedback silent = false, } < ------------------------------------------------------------------------------ *MiniTest.current* `MiniTest.current` Table with information about current state of test execution Use it to examine result of |MiniTest.execute()|. It is reset at the beginning of every call. At least these keys are supported: - - array with all cases being currently executed. Basically, an input of `MiniTest.execute()`. - - currently executed test case. See |MiniTest-test-case|. Use it to customize execution output (like adding custom notes, etc). ------------------------------------------------------------------------------ *MiniTest.new_set()* `MiniTest.new_set`({opts}, {tbl}) Create test set Test set is one of the two fundamental data structures. It is a table that defines hierarchical test organization as opposed to sequential organization with |MiniTest-test-case|. All its elements are one of three categories: - A callable (object that can be called; function or table with `__call` metatble entry) is considered to define a test action. It will be called with "current arguments" (result of all nested `parametrize` values, read further). If it throws error, test has failed. - A test set (output of this function) defines nested structure. Its options during collection (see |MiniTest.collect()|) will be extended with options of this (parent) test set. - Any other elements are considered helpers and don't directly participate in test structure. Set options allow customization of test collection and execution (more details in `opts` description): - `hooks` - table with elements that will be called without arguments at predefined stages of test execution. - `parametrize` - array defining different arguments with which main test actions will be called. Any non-trivial parametrization will lead to every element (even nested) be "multiplied" and processed with every element of `parametrize`. This allows handling many different combination of tests with little effort. - `data` - table with user data that will be forwarded to cases. Primary objective is to be used for customized case filtering. Notes: - Preferred way of adding elements is by using syntax `T[name] = element`. This way order of added elements will be preserved. Any other way won't guarantee any order. - Supplied options `opts` are stored in `opts` field of metatable (`getmetatable(set).opts`). Parameters ~ {opts} `(table|nil)` Allowed options: - - table with fields: - - executed before first filtered node. - - executed before each case (even nested). - - executed after each case (even nested). - - executed after last filtered node. - - array where each element is itself an array of parameters to be appended to "current parameters" of callable fields. Note: don't use plain `{}` as it is equivalent to "parametrization into zero cases", so no cases will be collected from this set. Calling test actions with no parameters is equivalent to `{{}}` or not supplying `parametrize` option at all. - - user data to be forwarded to cases. Can be used for a more granular filtering. - - number of times to retry each case until success. Default: 1. {tbl} `(table|nil)` Initial test items (possibly nested). Will be executed without any guarantees on order. Return ~ `(table)` A single test set. Usage ~ >lua -- Use with defaults T = MiniTest.new_set() T['works'] = function() MiniTest.expect.equality(1, 1) end -- Use with custom options. This will result into two actual cases: first -- will pass, second - fail after two attempts. T['nested'] = MiniTest.new_set({ hooks = { pre_case = function() _G.x = 1 end }, parametrize = { { 1 }, { 2 } }, n_retry = 2, }) T['nested']['works'] = function(x) MiniTest.expect.equality(_G.x, x) end < ------------------------------------------------------------------------------ *MiniTest-test-case* Test case An item of sequential test organization, as opposed to hierarchical with test set (see |MiniTest.new_set()|). It is created as result of test collection with |MiniTest.collect()| to represent all necessary information of test execution. Execution of test case goes by the following rules: - Call functions in order: - All elements of `hooks.pre` from first to last without arguments. - Field `test` with arguments unpacked from `args`. If execution fails, retry it (along with hooks that come from `pre_case` and `post_case`) at most `n_retry` times until first success (if any). - All elements of `hooks.post` from first to last without arguments. - Error in any call gets appended to `exec.fails`, meaning error in any hook will lead to test fail. - State (`exec.state`) is changed before every call and after last call. Class ~ {Test-case} Fields ~ {args} `(table)` Array of arguments with which `test` will be called. {data} `(table)` User data: all fields of `opts.data` from nested test sets. {desc} `(table)` Description: array of fields from nested test sets. {exec} `(table|nil)` Information about test case execution. Value of `nil` means that this particular case was not (yet) executed. Has following fields: - - array of strings with failing information. - - array of strings with non-failing information. - - state of test execution. One of: - `'Executing '` (during execution). - `'Pass'` (no fails, no notes). - `'Pass with notes'` (no fails, some notes). - `'Fail'` (some fails, no notes). - `'Fail with notes'` (some fails, some notes). {hooks} `(table)` Hooks to be executed as part of test case. Has fields: -
 and  - arrays of functions to be consecutively executed
    before and after every execution of `test`.
  -  and  - arrays of strings with sources of
    corresponding elements in 
 and  arrays. Source is one of
    `"once"` (for `pre_once` and `post_once` hooks) and
    `"case"` (for `pre_case` and `post_case` hooks).
{test} `(function|table)` Main callable object representing test action.

------------------------------------------------------------------------------
                                                               *MiniTest.skip()*
                             `MiniTest.skip`({msg})
Skip the rest of current case

Notes:
- When called inside test case, stops execution while adding message to notes.
- When called inside `pre_case` hook, registers skip at the start of its
  test case. Calling in other hooks has no effect.
- Currently implemented as a specially handled type of error.

Parameters ~
{msg} `(string|nil)` Message to be added to current case notes.

------------------------------------------------------------------------------
                                                           *MiniTest.add_note()*
                           `MiniTest.add_note`({msg})
Add note to currently executed test case

Appends `msg` to `exec.notes` field of `case` in |MiniTest.current|.

Parameters ~
{msg} `(string)` Note to add.

------------------------------------------------------------------------------
                                                            *MiniTest.finally()*
                            `MiniTest.finally`({f})
Register callable execution after current callable

Can be used several times inside hooks and main test callable of test case.

Parameters ~
{f} `(function|table)` Callable to be executed after current callable is
  finished executing (regardless of whether it ended with error or not).

------------------------------------------------------------------------------
                                                                *MiniTest.run()*
                             `MiniTest.run`({opts})
Run tests

- Try executing project specific script at path `opts.script_path`. If
  successful (no errors), then stop.
- Collect cases with |MiniTest.collect()| and `opts.collect`.
- Execute collected cases with |MiniTest.execute()| and `opts.execute`.

Parameters ~
{opts} `(table|nil)` Options with structure similar to |MiniTest.config|.
  Absent values are inferred from there.

------------------------------------------------------------------------------
                                                           *MiniTest.run_file()*
                      `MiniTest.run_file`({file}, {opts})
Run specific test file

Basically a |MiniTest.run()| wrapper with custom `collect.find_files` option.

Parameters ~
{file} `(string|nil)` Path to test file. By default a path of current buffer.
{opts} `(table|nil)` Options for |MiniTest.run()|.

------------------------------------------------------------------------------
                                                    *MiniTest.run_at_location()*
                 `MiniTest.run_at_location`({location}, {opts})
Run case(s) covering location

Try filtering case(s) covering location, meaning that definition of its
main `test` action (as taken from builtin `debug.getinfo`) is located in
specified file and covers specified line. Note that it can result in
multiple cases if they come from parametrized test set (see `parametrize`
option in |MiniTest.new_set()|).

Basically a |MiniTest.run()| wrapper with custom `collect.find_files` option.

Parameters ~
{location} `(table|nil)` Table with fields  (path to file) and 
  (line number in that file). Default is taken from current cursor position.

------------------------------------------------------------------------------
                                                            *MiniTest.collect()*
                           `MiniTest.collect`({opts})
Collect test cases

Overview of collection process:
- If `opts.emulate_busted` is `true`, temporary make special global
  functions (removed at the end of collection). They can be used inside
  test files to create hierarchical structure of test cases.
- Source each file from array output of `opts.find_files`. It should output
  a test set (see |MiniTest.new_set()|) or `nil` (if "busted" style is used;
  test set is created implicitly).
- Combine all test sets into single set with fields equal to its file path.
- Convert from hierarchical test configuration to sequential: from single
  test set to array of test cases (see |MiniTest-test-case|). Conversion is
  done in the form of "for every table element do: for every `parametrize`
  element do: ...". Details:
    - If element is a callable, construct test case with it being main
      `test` action. Description is appended with key of element in current
      test set table. Hooks, arguments, and data are taken from "current
      nested" ones. Add case to output array.
    - If element is a test set, process it in similar, recursive fashion.
      The "current nested" information is expanded:
        - `args` is extended with "current element" from `parametrize`.
        - `desc` is appended with element key.
        - `hooks` are appended to their appropriate places. `*_case` hooks
          will be inserted closer to all child cases than hooks from parent
          test sets: `pre_case` at end, `post_case` at start.
        - `data` is extended via |vim.tbl_deep_extend()|.
    - Any other element is not processed.
- Filter array with `opts.filter_cases`. Note that input case doesn't contain
  all hooks, as `*_once` hooks will be added after filtration.
- Add `*_once` hooks to appropriate cases.

Parameters ~
{opts} `(table|nil)` Options controlling case collection. Possible fields:
  -  - whether to emulate `lunarmodules/busted` interface.
    It emulates these global functions: `describe`, `it`, `setup`, `teardown`,
    `before_each`, `after_each`. Use |MiniTest.skip()| instead of `pending()`
    and |MiniTest.finally()| instead of `finally`.
  -  - function which when called without arguments returns
    array with file paths. Each file should be a Lua file returning single
    test set or `nil`.
  -  - function which when called with single test case
    (see |MiniTest-test-case|) returns `false` if this case should be filtered
    out; `true` otherwise.

Return ~
`(table)` Array of test cases ready to be used by |MiniTest.execute()|.

------------------------------------------------------------------------------
                                                            *MiniTest.execute()*
                      `MiniTest.execute`({cases}, {opts})
Execute array of test cases

Overview of execution process:
- Reset `all_cases` in |MiniTest.current| with `cases` input.
- Call `reporter.start(cases)` (if present).
- Execute each case in natural array order (aligned with their integer
  keys). Set `MiniTest.current.case` to currently executed case. Detailed
  test case execution is described in |MiniTest-test-case|. After any state
  change (including case retry attempts), call `reporter.update(case_num)`
  (if present), where `case_num` is an integer key of current test case.
- Call `reporter.finish()` (if present).

Notes:
- Execution is done in asynchronous fashion with scheduling. This allows
  making meaningful progress report during execution.
- This function doesn't return anything. Instead, it updates `cases` in
  place with proper `exec` field. Use `all_cases` at |MiniTest.current| to
  look at execution result.

Parameters ~
{cases} `(table)` Array of test cases (see |MiniTest-test-case|).
{opts} `(table|nil)` Options controlling case collection. Possible fields:
  -  - table with possible callable fields `start`, `update`,
    `finish`. Default: |MiniTest.gen_reporter.buffer()| in interactive
    usage and |MiniTest.gen_reporter.stdout()| in headless usage.
  -  - whether to stop execution (see |MiniTest.stop()|)
    after first error. Default: `false`.

------------------------------------------------------------------------------
                                                               *MiniTest.stop()*
                            `MiniTest.stop`({opts})
Stop test execution

Parameters ~
{opts} `(table|nil)` Options with fields:
  -  - whether to close all child neovim processes
    created with |MiniTest.new_child_neovim()|. Default: `true`.

------------------------------------------------------------------------------
                                                       *MiniTest.is_executing()*
                           `MiniTest.is_executing`()
Check if tests are being executed

Return ~
`(boolean)`

------------------------------------------------------------------------------
                                                               *MiniTest.expect*
                               `MiniTest.expect`
Table with expectation functions

Each function has the following behavior:
- Silently returns `true` if expectation is fulfilled.
- Throws an informative error with information helpful for debugging.
  Allows customizable fail reason to provide more context.

Mostly designed to be used within |mini.test| framework.

Usage ~
>lua
  local x = 1 + 1
  MiniTest.expect.equality(x, 2) -- passes
  MiniTest.expect.equality(x, 1, { fail_reason = 'Not equal' }) -- fails
<
------------------------------------------------------------------------------
                                                    *MiniTest.expect.equality()*
              `MiniTest.expect.equality`({left}, {right}, {opts})
Expect equality of two objects

Equality is tested via |vim.deep_equal()|. It also tries to compute more
detailed cause for equality (for easier spotting the difference):
- If they have different types.
- For strings if they have different length or if some character is different.
- For tables it shows a "key branch" at which values are different along with
  the actual values. A single difference is shown, there might be more.
  For not nested tables key branch is just a key. If the difference is inside
  nested tables, the key branch shows a "path through nested tables" to
  a different value. Examples: >lua

    local eq = MiniTest.expect.equality
    eq({ 1, 2 }, { 1, 3 })         -- Key branch is `2`
    eq({ 1, { 2 } }, { 1, 'c' })   -- Key branch is `2` ('c' is not a table)
    eq({ 1, { 2 } }, { 1, { 3 } }) -- Key branch is `2->1`

    -- Key branch is either `1->1->"a"` or `1->1->"b"`
    eq({ { { a = 1 } } }, { { { b = 2 } } })
<
Parameters ~
{left} `(any)` First object.
{right} `(any)` Second object.
{opts} `(table|nil)` Options. Possible fields:
  -  `(string|function)` - reason for failing expectation.
    a function is called with expectation input and should return a string.
    Default: `nil` for default reason like "Failed expectation for ...".

------------------------------------------------------------------------------
                                                 *MiniTest.expect.no_equality()*
             `MiniTest.expect.no_equality`({left}, {right}, {opts})
Expect no equality of two objects

Equality is tested via |vim.deep_equal()|.

Parameters ~
{left} `(any)` First object.
{right} `(any)` Second object.
{opts} `(table|nil)` Options. Possible fields:
  -  `(string|function)` - reason for failing expectation.
    a function is called with expectation input and should return a string.
    Default: `nil` for default reason like "Failed expectation for ...".

------------------------------------------------------------------------------
                                                       *MiniTest.expect.error()*
             `MiniTest.expect.error`({f}, {pattern}, {opts}, {...})
Expect function call to raise error

Parameters ~
{f} `(function)` Function to be tested for raising error.
{pattern} `(string|nil)` Pattern which error message should match.
  Use `nil` or empty string to not test for pattern matching.
{opts} `(table|nil)` Options. Possible fields:
  -  `(string|function)` - reason for failing expectation.
    a function is called with expectation input and should return a string.
    Default: `nil` for default reason like "Failed expectation for ...".

------------------------------------------------------------------------------
                                                    *MiniTest.expect.no_error()*
                 `MiniTest.expect.no_error`({f}, {opts}, {...})
Expect function call to not raise error

Parameters ~
{f} `(function)` Function to be tested for not raising error.
{opts} `(table|nil)` Options. Possible fields:
  -  `(string|function)` - reason for failing expectation.
    a function is called with expectation input and should return a string.
    Default: `nil` for default reason like "Failed expectation for ...".

------------------------------------------------------------------------------
                                        *MiniTest.expect.reference_screenshot()*
      `MiniTest.expect.reference_screenshot`({screenshot}, {path}, {opts})
Expect equality to reference screenshot

Parameters ~
{screenshot} `(table|nil)` Array with screenshot information. Usually an output
  of `child.get_screenshot()` (see |MiniTest-child-neovim-get_screenshot()|).
  If `nil`, expectation passed.
{path} `(string|nil)` Path to reference screenshot. If `nil`, constructed
  automatically in directory `opts.directory` from current case info and
  total number of times it was called inside current case. If there is no
  file at `path`, it is created with content of `screenshot`.
{opts} `(table|nil)` Options:
  -  `(boolean)` - whether to forcefully create reference screenshot.
    Temporary useful during test writing. Default: `false`.
  -  `(boolean|table)` - whether to ignore all or some text lines.
    If `true` - ignore all, if number array - ignore text of those lines,
    if `false` - do not ignore any. Default: `false`.
  -  `(boolean|table)` - whether to ignore all or some attr lines.
    If `true` - ignore all, if number array - ignore attr of those lines,
    if `false` - do not ignore any. Default: `false`.
  -  `(string)` - directory where automatically constructed `path`
    is located. Default: "tests/screenshots".
  -  `(string|function)` - reason for failing expectation.
    a function is called with expectation input and should return a string.
    Default: `nil` for default reason like "Failed expectation for ...".

------------------------------------------------------------------------------
                                                    *MiniTest.new_expectation()*
       `MiniTest.new_expectation`({subject}, {predicate}, {fail_context})
Create new expectation function

Helper for writing custom functions with behavior similar to other methods
of |MiniTest.expect|.

Parameters ~
{subject} `(string|function|table)` Subject of expectation. If callable,
  called with expectation input arguments to produce string value.
{predicate} `(function|table)` Predicate callable. Called with expectation
  input arguments. Output `false` or `nil` means failed expectation.
{fail_context} `(string|function|table)` Information about fail. If callable,
  called with expectation input arguments to produce string value.

Return ~
`(function)` Expectation function.

Usage ~
>lua
  local expect_truthy = MiniTest.new_expectation(
    'truthy',
    function(x) return x end,
    function(x) return 'Object: ' .. vim.inspect(x) end
  )
<
------------------------------------------------------------------------------
                                                         *MiniTest.gen_reporter*
                            `MiniTest.gen_reporter`
Table with pre-configured report generators

Each element is a function which returns reporter - table with callable
`start`, `update`, and `finish` fields.

------------------------------------------------------------------------------
                                                *MiniTest.gen_reporter.buffer()*
                     `MiniTest.gen_reporter.buffer`({opts})
Generate buffer reporter

This is a default choice for interactive (not headless) usage. Opens a window
with dedicated non-terminal buffer and updates it with throttled redraws.

Opened buffer has the following helpful Normal mode mappings:
- `` - stop test execution if executing (see |MiniTest.is_executing()|
  and |MiniTest.stop()|). Close window otherwise.
- `q` - same as `` for convenience and compatibility.

General idea:
- Group cases by concatenating first `opts.group_depth` elements of case
  description (`desc` field). Groups by collected files if using default values.
- In `start()` show some stats to know how much is scheduled to be executed.
- In `update()` show symbolic overview of current group and state of current
  case. Each symbol represents one case and its state:
    - `?` - case didn't finish executing.
    - `o` - pass.
    - `O` - pass with notes.
    - `x` - fail.
    - `X` - fail with notes.
- In `finish()` show all fails and notes ordered by case.

Parameters ~
{opts} `(table|nil)` Table with options. Used fields:
  -  - number of first elements of case description (can be zero)
    used for grouping. Higher values mean higher granularity of output.
    Default: 1.
  -  - minimum number of milliseconds to wait between
    redrawing. Reduces screen flickering but not amount of computations.
    Default: 10.
  -  - definition of window to open. Can take one of the forms:
      - Callable. It is called expecting output to be target window id
        (current window is used if output is `nil`). Use this to open in
        "normal" window (like `function() vim.cmd('vsplit') end`).
      - Table. Used as `config` argument in |nvim_open_win()|.
    Default: table for centered floating window.

------------------------------------------------------------------------------
                                                *MiniTest.gen_reporter.stdout()*
                     `MiniTest.gen_reporter.stdout`({opts})
Generate stdout reporter

This is a default choice for headless usage. Writes to `stdout`. Uses
coloring ANSI escape sequences to make pretty and informative output
(should work in most modern terminals and continuous integration providers).

It has same general idea as |MiniTest.gen_reporter.buffer()| with slightly
less output (it doesn't overwrite previous text) to overcome typical
terminal limitations.

Parameters ~
{opts} `(table|nil)` Table with options. Used fields:
  -  - number of first elements of case description (can be zero)
    used for grouping. Higher values mean higher granularity of output.
    Default: 1.
  -  - whether to quit after finishing test execution.
    Default: `true`.

------------------------------------------------------------------------------
                                                   *MiniTest.new_child_neovim()*
                         `MiniTest.new_child_neovim`()
Create child Neovim process

This creates an object designed to be a fundamental piece of |mini.test|
methodology. It can start/stop/restart a separate (child) Neovim process
(headless, but fully functioning) together with convenience helpers to
interact with it through |RPC| messages.

For more information see |MiniTest-child-neovim|.

Return ~
`(MiniTest.child)` Object of |MiniTest-child-neovim|.

Usage ~
>lua
  -- Initiate
  local child = MiniTest.new_child_neovim()
  child.start()

  -- Use API functions
  child.api.nvim_buf_set_lines(0, 0, -1, true, { 'Line inside child Neovim' })

  -- Execute Lua code, Vimscript commands, etc.
  child.lua('_G.n = 0')
  child.cmd('au CursorMoved * lua _G.n = _G.n + 1')
  child.type_keys('l')
  print(child.lua_get('_G.n')) -- Should be 1

  -- Use other `vim.xxx` Lua wrappers (executed inside child process)
  vim.b.aaa = 'current process'
  child.b.aaa = 'child process'
  print(child.lua_get('vim.b.aaa')) -- Should be 'child process'

  -- Always stop process after it is not needed
  child.stop()
<
------------------------------------------------------------------------------
                                                         *MiniTest-child-neovim*
Child class

It offers a great set of tools to write reliable and reproducible tests by
allowing to use fresh process in any test action. Interaction with it is done
through |RPC| protocol.

Although quite flexible, at the moment it has certain limitations:
- Doesn't allow using functions or userdata for child's both inputs and
  outputs. Usual solution is to move computations from current Neovim process
  to child process. Use `child.lua()` and `child.lua_get()` for that.
- When writing tests, it is common to end up with "hanging" process: it
  stops executing without any output. Most of the time it is because Neovim
  process is "blocked", i.e. it waits for user input and won't return from
  other call (like `child.api.nvim_exec_lua()`). Common causes are active
  |hit-enter-prompt| (increase prompt height to a bigger value) or
  Operator-pending mode (exit it). To mitigate this experience, most helpers
  will throw an error if its immediate execution will lead to hanging state.
  Also in case of hanging state try `child.api_notify` instead of `child.api`.

Notes:
- An important type of field is a "redirection table". It acts as a
  convenience wrapper for corresponding `vim.*` table. Can be used both to
  return and set values. Examples:
    - `child.api.nvim_buf_line_count(0)` will execute
      `vim.api.nvim_buf_line_count(0)` inside child process and return its
      output to current process.
    - `child.bo.filetype = 'lua'` will execute `vim.bo.filetype = 'lua'`
      inside child process.
  They still have same limitations listed above, so are not perfect. In
  case of a doubt, use `child.lua()`.
- Almost all methods use |vim.rpcrequest()| (i.e. wait for call to finish and
  then return value). See for `*_notify` variant to use |vim.rpcnotify()|.
- All fields and methods should be called with `.`, not `:`.

Class ~
{MiniTest.child}

Fields ~
{start} `(function)` Start child process. See |MiniTest-child-neovim-start()|.
{stop} `(function)` Stop current child process.
{restart} `(function)` Restart child process: stop if running and then
  start a new one. Takes same arguments as `child.start()` but uses values
  from most recent `start()` call as defaults.

{type_keys} `(function)` Emulate typing keys.
  See |MiniTest-child-neovim-type_keys()|. Doesn't check for blocked state.

{cmd} `(function)` Execute Vimscript code from a string.
  A wrapper for |nvim_exec()| without capturing output.
{cmd_capture} `(function)` Execute Vimscript code from a string and
  capture output. A wrapper for |nvim_exec()| with capturing output.

{lua} `(function)` Execute Lua code. A wrapper for |nvim_exec_lua()|.
{lua_notify} `(function)` Execute Lua code without waiting for output.
{lua_get} `(function)` Execute Lua code and return result. A wrapper
  for |nvim_exec_lua()| but prepends string code with `return`.
{lua_func} `(function)` Execute Lua function and return it's result.
  Function will be called with all extra parameters (second one and later).
  Note: usage of upvalues (data from outside function scope) is not allowed.

{is_blocked} `(function)` Check whether child process is blocked.
{is_running} `(function)` Check whether child process is currently running.

{ensure_normal_mode} `(function)` Ensure normal mode.
{get_screenshot} `(function)` Returns table with two "2d arrays" of single
  characters representing what is displayed on screen and how it looks.
  Has `opts` table argument for optional configuratnion.

{job} `(table|nil)` Information about current job. If `nil`, child is not running.

{api} `(table)` Redirection table for `vim.api`. Doesn't check for blocked state.
{api_notify} `(table)` Same as `api`, but uses |vim.rpcnotify()|.

{diagnostic} `(table)` Redirection table for |vim.diagnostic|.
{fn} `(table)` Redirection table for |vim.fn|.
{highlight} `(table)` Redirection table for |vim.highlight|.
{hl} `(table)` Redirection table for |vim.hl|.
{json} `(table)` Redirection table for `vim.json`.
{loop} `(table)` Redirection table for |vim.loop|.
{lsp} `(table)` Redirection table for `vim.lsp` (|lsp-core|).
{mpack} `(table)` Redirection table for |vim.mpack|.
{spell} `(table)` Redirection table for |vim.spell|.
{treesitter} `(table)` Redirection table for `vim.treesitter` (|lua-treesitter-core|).
{ui} `(table)` Redirection table for |vim.ui|. Currently of no
  use because it requires sending function through RPC, which is impossible
  at the moment.
{fs} `(table)` Redirection table for |vim.fs|.

{g} `(table)` Redirection table for |vim.g|.
{b} `(table)` Redirection table for |vim.b|.
{w} `(table)` Redirection table for |vim.w|.
{t} `(table)` Redirection table for |vim.t|.
{v} `(table)` Redirection table for |vim.v|.
{env} `(table)` Redirection table for |vim.env|.

{o} `(table)` Redirection table for |vim.o|.
{go} `(table)` Redirection table for |vim.go|.
{bo} `(table)` Redirection table for |vim.bo|.
{wo} `(table)` Redirection table for |vim.wo|.

------------------------------------------------------------------------------
                                                 *MiniTest-child-neovim-start()*
                          `child.start`({args}, {opts})

Start child process and connect to it. Won't work if child is already running.

Parameters ~
{args} `(table)` Array with arguments for executable. Will be prepended with
  the following default arguments (see |startup-options|): >lua
  { '--clean', '-n', '--listen', ,
    '--headless', '--cmd', 'set lines=24 columns=80' }
<
{opts} `(table|nil)` Options:
  -  - name of Neovim executable. Default: |v:progpath|.
  -  - stop trying to connect after this amount of
    milliseconds. Default: 5000.

Usage ~
>lua
  child = MiniTest.new_child_neovim()

  -- Start default clean Neovim instance
  child.start()

  -- Start with custom 'init.lua' file
  child.start({ '-u', 'scripts/minimal_init.lua' })
<
------------------------------------------------------------------------------
                                             *MiniTest-child-neovim-type_keys()*
                       `child.type_keys`({wait}, {...})

Basically a wrapper for |nvim_input()| applied inside child process.
Differences:
- Can wait after each group of characters.
- Raises error if typing keys resulted into error in child process (i.e. its
  |v:errmsg| was updated).
- Key `<` as a separate entry may not be escaped as ``.

Parameters ~
{wait} `(number|nil)` Number of milliseconds to wait after each entry. May be
  omitted, in which case no waiting is done.
{...} `(string|table)` Separate entries for |nvim_input()|,
  after which `wait` will be applied. Can be either string or array of strings.

Usage ~
>lua
  -- All of these type keys 'c', 'a', 'w'
  child.type_keys('caw')
  child.type_keys('c', 'a', 'w')
  child.type_keys('c', { 'a', 'w' })

  -- Waits 5 ms after `c` and after 'w'
  child.type_keys(5, 'c', { 'a', 'w' })

  -- Special keys can also be used
  child.type_keys('i', 'Hello world', '')
<
------------------------------------------------------------------------------
                                        *MiniTest-child-neovim-get_screenshot()*
                        `child.get_screenshot`({opts})

Compute what is displayed on (default TUI) screen and how it is displayed.
This basically calls |screenstring()| and |screenattr()| for every visible
cell (row from 1 to |'lines'|, column from 1 to |'columns'|).

Notes:
- To make output more portable and visually useful, outputs of
  `screenattr()` are coded with single character symbols. Those are taken from
  94 characters (ASCII codes between 33 and 126), so there will be duplicates
  in case of more than 94 different ways text is displayed on screen.

Parameters ~
{opts} `(table|nil)` Options. Possieble fields:
  -  `(boolean)` - whether to call |:redraw| prior to computing
    screenshot. Default: `true`.

Return ~
`(table|nil)` Screenshot table with the following fields:
  -  - "2d array" (row-column) of single characters displayed at
    particular cells.
  -  - "2d array" (row-column) of symbols representing how text is
    displayed (basically, "coded" appearance/highlighting). They should be
    used only in relation to each other: same/different symbols for two
    cells mean same/different visual appearance. Note: there will be false
    positives if there are more than 94 different attribute values.
  It also can be used with `tostring()` to convert to single string (used
  for writing to reference file). It results into two visual parts
  (separated by empty line), for `text` and `attr`. Each part has "ruler"
  above content and line numbers for each line.
  Returns `nil` if couldn't get a reasonable screenshot.

Usage ~
>lua
  local screenshot = child.get_screenshot()

  -- Show character displayed row=3 and column=4
  print(screenshot.text[3][4])

  -- Convert to string
  tostring(screenshot)
<

 vim:tw=78:ts=8:noet:ft=help:norl:nvim-mini-mini.test-6f129de/lua/000077500000000000000000000000001521526606100165345ustar00rootroot00000000000000nvim-mini-mini.test-6f129de/lua/mini/000077500000000000000000000000001521526606100174705ustar00rootroot00000000000000nvim-mini-mini.test-6f129de/lua/mini/test.lua000066400000000000000000002770331521526606100211660ustar00rootroot00000000000000--- *mini.test* Test Neovim plugins
---
--- MIT License Copyright (c) 2022 Evgeni Chasnovski

--- Features:
--- - Test action is defined as a named callable entry of a table.
---
--- - Helper for creating child Neovim process which is designed to be used in
---   tests (including taking and verifying screenshots). See
---   |MiniTest.new_child_neovim()| and |MiniTest.expect.reference_screenshot()|.
---
--- - Hierarchical organization of tests with custom hooks, parametrization,
---   and user data. See |MiniTest.new_set()|.
---
--- - Emulation of [lunarmodules/busted](https://github.com/lunarmodules/busted)
---   interface (`describe`, `it`, etc.).
---
--- - Predefined small yet usable set of expectations (`assert`-like functions).
---   See |MiniTest.expect|.
---
--- - Customizable definition of what files should be tested.
---
--- - Test case filtering. There are predefined wrappers for testing a file
---   (|MiniTest.run_file()|) and case at a location like current cursor position
---   (|MiniTest.run_at_location()|).
---
--- - Customizable reporter of output results. There are two predefined ones:
---     - |MiniTest.gen_reporter.buffer()| for interactive usage.
---     - |MiniTest.gen_reporter.stdout()| for headless Neovim.
---
--- - Customizable project specific testing script.
---
--- - Works on Unix (Linux, MacOS, etc.) and Windows.
---
--- What it doesn't support:
--- - Parallel execution. Due to idea of limiting implementation complexity.
---
--- - Mocks, stubs, etc. Use child Neovim process and manually override what is
---   needed. Reset child process it afterwards.
---
--- - "Overly specific" expectations. Tests for (no) equality and (absence of)
---   errors usually cover most of the needs. Adding new expectations is a
---   subject to weighing its usefulness against additional implementation
---   complexity. Use |MiniTest.new_expectation()| to create custom ones.
---
--- For more information see:
--- - `TESTING.md` file for a hands-on introduction based on examples.
---
--- - Code of this plugin's tests. Consider it to be an example of intended
---   way to use |mini.test| for test organization and creation.
---
--- # Workflow ~
---
--- - Organize tests in separate files. Each test file should return a test set
---   (explicitly or implicitly by using "busted" style functions).
---
--- - Write test actions as callable entries of test set. Use child process
---   inside test actions (see |MiniTest.new_child_neovim()|) and builtin
---   expectations (see |MiniTest.expect|).
---
--- - Run tests. This does two steps:
---     - Collect. This creates single hierarchical test set, flattens into
---       array of test cases (see |MiniTest-test-case|) while expanding with
---       parametrization, and possibly filters them.
---     - Execute. This safely calls hooks and main test actions in specified
---       order while allowing reporting progress in asynchronous fashion.
---       Detected errors means test case fail; otherwise - pass.
---
--- # Setup ~
---
--- This module needs a setup with `require('mini.test').setup({})` (replace
--- `{}` with your `config` table). It will create global Lua table `MiniTest`
--- which you can use for scripting or manually (with `:lua MiniTest.*`).
---
--- See |MiniTest.config| for available config settings.
---
--- You can override runtime config settings locally to buffer inside
--- `vim.b.minitest_config` which should have same structure as `MiniTest.config`.
--- See |mini.nvim-buffer-local-config| for more details.
---
--- To stop module from showing non-error feedback, set `config.silent = true`.
---
--- # Comparisons ~
---
--- - Testing infrastructure from
---   [nvim-lua/plenary.nvim](https://github.com/nvim-lua/plenary.nvim):
---     - Executes each file in separate headless Neovim process with customizable
---       `init.vim` file. While |mini.test| executes everything in current
---       Neovim process encouraging writing tests with help of manually
---       managed child Neovim process (see |MiniTest.new_child_neovim()|).
---     - Tests are expected to be written with embedded simplified versions of
---       `lunarmodules/busted` and `lunarmodules/luassert`. While |mini.test|
---       uses concepts of test set (see |MiniTest.new_set()|) and test case
---       (see |MiniTest-test-case|). It also can emulate bigger part of
---       "busted" framework.
---     - Has single way of reporting progress (shows result after every case
---       without summary). While |mini.test| can have customized reporters
---       with defaults for interactive and headless usage (provide more
---       compact and user-friendly summaries).
---     - Allows parallel execution, while |mini.test| does not.
---     - Allows making mocks, stubs, and spies, while |mini.test| does not in
---       favor of manually overwriting functionality in child Neovim process.
---
--- Although |mini.test| supports emulation of "busted style" testing, it will
--- be more stable to use its designed approach of defining tests (with
--- `MiniTest.new_set()` and explicit table fields). Couple of reasons:
--- - "Busted" syntax doesn't support full capabilities offered by |mini.test|.
---   Mainly it is about parametrization and supplying user data to test sets.
--- - It is an emulation, not full support. So some subtle things might not
---   work the way you expect.
---
--- Some hints for converting from `plenary.nvim` tests to |mini.test|:
--- - Rename files from `***_spec.lua` to `test_***.lua` and put them in
---   "tests" directory.
--- - Replace `assert` calls with |mini.test| expectations. See |MiniTest.expect|.
--- - Create main test set `T = MiniTest.new_set()` and eventually return it.
--- - Make new sets (|MiniTest.new_set()|) from `describe` blocks. Convert
---   `before_each()` and `after_each` to `pre_case` and `post_case` hooks.
--- - Make test cases from `it` blocks.
---
--- # Highlight groups ~
--- *MiniTest-hl-groups*
---
--- - `MiniTestEmphasis` - emphasis highlighting. By default it is a bold text.
--- - `MiniTestFail` - highlighting of failed cases. By default it is a bold
---   text with `vim.g.terminal_color_1` color (red).
--- - `MiniTestPass` - highlighting of passed cases. By default it is a bold
---   text with `vim.g.terminal_color_2` color (green).
---
--- To change any highlight group, set it directly with |nvim_set_hl()|.
---
--- # Disabling ~
---
--- To disable, set `vim.g.minitest_disable` (globally) or `vim.b.minitest_disable`
--- (for a buffer) to `true`. Considering high number of different scenarios
--- and customization intentions, writing exact rules for disabling module's
--- functionality is left to user. See |mini.nvim-disabling-recipes| for common
--- recipes.
---@tag MiniTest

---@alias __test_expect_fail_reason -  `(string|function)` - reason for failing expectation.
---     a function is called with expectation input and should return a string.
---     Default: `nil` for default reason like "Failed expectation for ...".

-- Module definition ==========================================================
local MiniTest = {}
local H = {}

--- Module setup
---
---@param config table|nil Module config table. See |MiniTest.config|.
---
---@usage >lua
---   require('mini.test').setup() -- use default config
---   -- OR
---   require('mini.test').setup({}) -- replace {} with your config table
--- <
MiniTest.setup = function(config)
  -- TODO: Remove after Neovim=0.9 support is dropped
  if vim.fn.has('nvim-0.10') == 0 then
    vim.notify(
      '(mini.test) Neovim<0.10 is soft deprecated (module works but is not supported).'
        .. " It will be deprecated after the next 'mini.nvim' release (module might not work)."
        .. ' Please update your Neovim version.'
    )
  end

  -- Export module
  _G.MiniTest = MiniTest

  -- Setup config
  config = H.setup_config(config)

  -- Apply config
  H.apply_config(config)

  -- Define behavior
  H.create_autocommands()

  -- Create default highlighting
  H.create_default_hl()
end

--stylua: ignore start
--- Defaults ~
---@eval return MiniDoc.afterlines_to_code(MiniDoc.current.eval_section)
MiniTest.config = {
  -- Options for collection of test cases. See `:h MiniTest.collect()`.
  collect = {
    -- Temporarily emulate functions from 'busted' testing framework
    -- (`describe`, `it`, `before_each`, `after_each`, and more)
    emulate_busted = true,

    -- Function returning array of file paths to be collected.
    -- Default: all Lua files in 'tests' directory starting with 'test_'.
    find_files = function()
      return vim.fn.globpath('tests', '**/test_*.lua', true, true)
    end,

    -- Predicate function indicating if test case should be executed
    filter_cases = function(case) return true end,
  },

  -- Options for execution of test cases. See `:h MiniTest.execute()`.
  execute = {
    -- Table with callable fields `start()`, `update()`, and `finish()`
    reporter = nil,

    -- Whether to stop execution after first error
    stop_on_error = false,
  },

  -- Path (relative to current directory) to script which handles project
  -- specific test running
  script_path = 'scripts/minitest.lua',

  -- Whether to disable showing non-error feedback
  silent = false,
}
--minidoc_afterlines_end
--stylua: ignore end

-- Module data ================================================================
--- Table with information about current state of test execution
---
--- Use it to examine result of |MiniTest.execute()|. It is reset at the
--- beginning of every call.
---
--- At least these keys are supported:
--- -  - array with all cases being currently executed. Basically,
---   an input of `MiniTest.execute()`.
--- -  - currently executed test case. See |MiniTest-test-case|. Use it
---   to customize execution output (like adding custom notes, etc).
MiniTest.current = { all_cases = nil, case = nil }

-- Module functionality =======================================================
--- Create test set
---
--- Test set is one of the two fundamental data structures. It is a table that
--- defines hierarchical test organization as opposed to sequential
--- organization with |MiniTest-test-case|.
---
--- All its elements are one of three categories:
--- - A callable (object that can be called; function or table with `__call`
---   metatble entry) is considered to define a test action. It will be called
---   with "current arguments" (result of all nested `parametrize` values, read
---   further). If it throws error, test has failed.
--- - A test set (output of this function) defines nested structure. Its
---   options during collection (see |MiniTest.collect()|) will be extended
---   with options of this (parent) test set.
--- - Any other elements are considered helpers and don't directly participate
---   in test structure.
---
--- Set options allow customization of test collection and execution (more
--- details in `opts` description):
--- - `hooks` - table with elements that will be called without arguments at
---   predefined stages of test execution.
--- - `parametrize` - array defining different arguments with which main test
---   actions will be called. Any non-trivial parametrization will lead to
---   every element (even nested) be "multiplied" and processed with every
---   element of `parametrize`. This allows handling many different combination
---   of tests with little effort.
--- - `data` - table with user data that will be forwarded to cases. Primary
---   objective is to be used for customized case filtering.
---
--- Notes:
--- - Preferred way of adding elements is by using syntax `T[name] = element`.
---   This way order of added elements will be preserved. Any other way won't
---   guarantee any order.
--- - Supplied options `opts` are stored in `opts` field of metatable
---   (`getmetatable(set).opts`).
---
---@param opts table|nil Allowed options:
---   -  - table with fields:
---       -  - executed before first filtered node.
---       -  - executed before each case (even nested).
---       -  - executed after each case (even nested).
---       -  - executed after last filtered node.
---   -  - array where each element is itself an array of
---     parameters to be appended to "current parameters" of callable fields.
---     Note: don't use plain `{}` as it is equivalent to "parametrization into
---     zero cases", so no cases will be collected from this set. Calling test
---     actions with no parameters is equivalent to `{{}}` or not supplying
---     `parametrize` option at all.
---   -  - user data to be forwarded to cases. Can be used for a more
---     granular filtering.
---   -  - number of times to retry each case until success.
---     Default: 1.
---@param tbl table|nil Initial test items (possibly nested). Will be executed
---   without any guarantees on order.
---
---@return table A single test set.
---
---@usage >lua
---   -- Use with defaults
---   T = MiniTest.new_set()
---   T['works'] = function() MiniTest.expect.equality(1, 1) end
---
---   -- Use with custom options. This will result into two actual cases: first
---   -- will pass, second - fail after two attempts.
---   T['nested'] = MiniTest.new_set({
---     hooks = { pre_case = function() _G.x = 1 end },
---     parametrize = { { 1 }, { 2 } },
---     n_retry = 2,
---   })
---
---   T['nested']['works'] = function(x) MiniTest.expect.equality(_G.x, x) end
--- <
MiniTest.new_set = function(opts, tbl)
  opts = opts or {}
  tbl = tbl or {}

  -- Keep track of new elements order. This allows to iterate through elements
  -- in order they were added.
  local metatbl = { class = 'testset', key_order = vim.tbl_keys(tbl), opts = opts }
  metatbl.__newindex = function(t, key, value)
    table.insert(metatbl.key_order, key)
    rawset(t, key, value)
  end

  return setmetatable(tbl, metatbl)
end

--- Test case
---
--- An item of sequential test organization, as opposed to hierarchical with
--- test set (see |MiniTest.new_set()|). It is created as result of test
--- collection with |MiniTest.collect()| to represent all necessary information
--- of test execution.
---
--- Execution of test case goes by the following rules:
--- - Call functions in order:
---     - All elements of `hooks.pre` from first to last without arguments.
---     - Field `test` with arguments unpacked from `args`. If execution fails,
---       retry it (along with hooks that come from `pre_case` and `post_case`)
---       at most `n_retry` times until first success (if any).
---     - All elements of `hooks.post` from first to last without arguments.
--- - Error in any call gets appended to `exec.fails`, meaning error in any
---   hook will lead to test fail.
--- - State (`exec.state`) is changed before every call and after last call.
---
---@class Test-case
---
---@field args table Array of arguments with which `test` will be called.
---@field data table User data: all fields of `opts.data` from nested test sets.
---@field desc table Description: array of fields from nested test sets.
---@field exec table|nil Information about test case execution. Value of `nil` means
---   that this particular case was not (yet) executed. Has following fields:
---   -  - array of strings with failing information.
---   -  - array of strings with non-failing information.
---   -  - state of test execution. One of:
---       - `'Executing '` (during execution).
---       - `'Pass'` (no fails, no notes).
---       - `'Pass with notes'` (no fails, some notes).
---       - `'Fail'` (some fails, no notes).
---       - `'Fail with notes'` (some fails, some notes).
---@field hooks table Hooks to be executed as part of test case. Has fields:
---   - 
 and  - arrays of functions to be consecutively executed
---     before and after every execution of `test`.
---   -  and  - arrays of strings with sources of
---     corresponding elements in 
 and  arrays. Source is one of
---     `"once"` (for `pre_once` and `post_once` hooks) and
---     `"case"` (for `pre_case` and `post_case` hooks).
---@field test function|table Main callable object representing test action.
---@tag MiniTest-test-case

--- Skip the rest of current case
---
--- Notes:
--- - When called inside test case, stops execution while adding message to notes.
--- - When called inside `pre_case` hook, registers skip at the start of its
---   test case. Calling in other hooks has no effect.
--- - Currently implemented as a specially handled type of error.
---
---@param msg string|nil Message to be added to current case notes.
MiniTest.skip = function(msg)
  H.cache.skip_message = msg or 'Skip test'
  error(H.cache.skip_message, 0)
end

--- Add note to currently executed test case
---
--- Appends `msg` to `exec.notes` field of `case` in |MiniTest.current|.
---
---@param msg string Note to add.
MiniTest.add_note = function(msg)
  local case = MiniTest.current.case
  case.exec = case.exec or {}
  case.exec.notes = case.exec.notes or {}
  table.insert(case.exec.notes, msg)
end

--- Register callable execution after current callable
---
--- Can be used several times inside hooks and main test callable of test case.
---
---@param f function|table Callable to be executed after current callable is
---   finished executing (regardless of whether it ended with error or not).
MiniTest.finally = function(f) table.insert(H.cache.finally, f) end

--- Run tests
---
--- - Try executing project specific script at path `opts.script_path`. If
---   successful (no errors), then stop.
--- - Collect cases with |MiniTest.collect()| and `opts.collect`.
--- - Execute collected cases with |MiniTest.execute()| and `opts.execute`.
---
---@param opts table|nil Options with structure similar to |MiniTest.config|.
---   Absent values are inferred from there.
MiniTest.run = function(opts)
  if H.is_disabled() then return end

  -- Try sourcing project specific script first
  local success = H.execute_project_script(opts)
  if success then return end

  -- Collect and execute
  opts = H.get_config(opts)
  local cases = MiniTest.collect(opts.collect)
  MiniTest.execute(cases, opts.execute)
end

--- Run specific test file
---
--- Basically a |MiniTest.run()| wrapper with custom `collect.find_files` option.
---
---@param file string|nil Path to test file. By default a path of current buffer.
---@param opts table|nil Options for |MiniTest.run()|.
MiniTest.run_file = function(file, opts)
  file = vim.fn.fnamemodify(file or vim.api.nvim_buf_get_name(0), ':p:.')

  local stronger_opts = { collect = { find_files = function() return { file } end } }
  opts = vim.tbl_deep_extend('force', opts or {}, stronger_opts)

  MiniTest.run(opts)
end

--- Run case(s) covering location
---
--- Try filtering case(s) covering location, meaning that definition of its
--- main `test` action (as taken from builtin `debug.getinfo`) is located in
--- specified file and covers specified line. Note that it can result in
--- multiple cases if they come from parametrized test set (see `parametrize`
--- option in |MiniTest.new_set()|).
---
--- Basically a |MiniTest.run()| wrapper with custom `collect.find_files` option.
---
---@param location table|nil Table with fields  (path to file) and 
---   (line number in that file). Default is taken from current cursor position.
MiniTest.run_at_location = function(location, opts)
  if location == nil then
    local cur_file = vim.fn.fnamemodify(vim.api.nvim_buf_get_name(0), ':.')
    local cur_pos = vim.api.nvim_win_get_cursor(0)
    location = { file = cur_file, line = cur_pos[1] }
  end

  local stronger_opts = {
    collect = {
      find_files = function() return { location.file } end,
      filter_cases = function(case)
        local info = debug.getinfo(case.test)

        return info.short_src == location.file
          and info.linedefined <= location.line
          and location.line <= info.lastlinedefined
      end,
    },
  }
  opts = vim.tbl_deep_extend('force', opts or {}, stronger_opts)

  MiniTest.run(opts)
end

--- Collect test cases
---
--- Overview of collection process:
--- - If `opts.emulate_busted` is `true`, temporary make special global
---   functions (removed at the end of collection). They can be used inside
---   test files to create hierarchical structure of test cases.
--- - Source each file from array output of `opts.find_files`. It should output
---   a test set (see |MiniTest.new_set()|) or `nil` (if "busted" style is used;
---   test set is created implicitly).
--- - Combine all test sets into single set with fields equal to its file path.
--- - Convert from hierarchical test configuration to sequential: from single
---   test set to array of test cases (see |MiniTest-test-case|). Conversion is
---   done in the form of "for every table element do: for every `parametrize`
---   element do: ...". Details:
---     - If element is a callable, construct test case with it being main
---       `test` action. Description is appended with key of element in current
---       test set table. Hooks, arguments, and data are taken from "current
---       nested" ones. Add case to output array.
---     - If element is a test set, process it in similar, recursive fashion.
---       The "current nested" information is expanded:
---         - `args` is extended with "current element" from `parametrize`.
---         - `desc` is appended with element key.
---         - `hooks` are appended to their appropriate places. `*_case` hooks
---           will be inserted closer to all child cases than hooks from parent
---           test sets: `pre_case` at end, `post_case` at start.
---         - `data` is extended via |vim.tbl_deep_extend()|.
---     - Any other element is not processed.
--- - Filter array with `opts.filter_cases`. Note that input case doesn't contain
---   all hooks, as `*_once` hooks will be added after filtration.
--- - Add `*_once` hooks to appropriate cases.
---
---@param opts table|nil Options controlling case collection. Possible fields:
---   -  - whether to emulate `lunarmodules/busted` interface.
---     It emulates these global functions: `describe`, `it`, `setup`, `teardown`,
---     `before_each`, `after_each`. Use |MiniTest.skip()| instead of `pending()`
---     and |MiniTest.finally()| instead of `finally`.
---   -  - function which when called without arguments returns
---     array with file paths. Each file should be a Lua file returning single
---     test set or `nil`.
---   -  - function which when called with single test case
---     (see |MiniTest-test-case|) returns `false` if this case should be filtered
---     out; `true` otherwise.
---
---@return table Array of test cases ready to be used by |MiniTest.execute()|.
MiniTest.collect = function(opts)
  opts = vim.tbl_deep_extend('force', H.get_config().collect, opts or {})

  -- Make single test set
  local set = MiniTest.new_set()

  for _, file in ipairs(opts.find_files()) do
    -- Possibly emulate 'busted' with current file. This allows to wrap all
    -- implicit cases from that file into single set with file's name.
    if opts.emulate_busted then
      set[file] = MiniTest.new_set()
      H.busted_emulate(set[file])
    end

    -- Execute file
    local ok, t = pcall(dofile, file)

    -- Catch errors
    if not ok then
      local msg = string.format('Sourcing %s resulted into following error: %s', vim.inspect(file), t)
      H.error(msg)
    end
    local is_output_correct = (opts.emulate_busted and vim.tbl_count(set[file]) > 0) or H.is_instance(t, 'testset')
    if not is_output_correct then
      local msg = string.format(
        [[%s does not define a test set. Did you return `MiniTest.new_set()` or created 'busted' tests?]],
        vim.inspect(file)
      )
      H.error(msg)
    end

    -- If output is test set, always use it (even if 'busted' tests were added)
    if H.is_instance(t, 'testset') then set[file] = t end
  end

  H.busted_deemulate()

  -- Convert to test cases. This also creates separate aligned array of hooks
  -- which should be executed once regarding test case. This is needed to
  -- correctly inject those hooks after filtering is done.
  local raw_cases, raw_hooks_once = H.set_to_testcases(set)

  -- Filter cases (at this stage don't have injected `hooks_once`)
  local cases, hooks_once = {}, {}
  for i, c in ipairs(raw_cases) do
    if opts.filter_cases(c) then
      table.insert(cases, c)
      table.insert(hooks_once, raw_hooks_once[i])
    end
  end

  -- Inject `hooks_once` into appropriate cases
  H.inject_hooks_once(cases, hooks_once)

  return cases
end

--- Execute array of test cases
---
--- Overview of execution process:
--- - Reset `all_cases` in |MiniTest.current| with `cases` input.
--- - Call `reporter.start(cases)` (if present).
--- - Execute each case in natural array order (aligned with their integer
---   keys). Set `MiniTest.current.case` to currently executed case. Detailed
---   test case execution is described in |MiniTest-test-case|. After any state
---   change (including case retry attempts), call `reporter.update(case_num)`
---   (if present), where `case_num` is an integer key of current test case.
--- - Call `reporter.finish()` (if present).
---
--- Notes:
--- - Execution is done in asynchronous fashion with scheduling. This allows
---   making meaningful progress report during execution.
--- - This function doesn't return anything. Instead, it updates `cases` in
---   place with proper `exec` field. Use `all_cases` at |MiniTest.current| to
---   look at execution result.
---
---@param cases table Array of test cases (see |MiniTest-test-case|).
---@param opts table|nil Options controlling case collection. Possible fields:
---   -  - table with possible callable fields `start`, `update`,
---     `finish`. Default: |MiniTest.gen_reporter.buffer()| in interactive
---     usage and |MiniTest.gen_reporter.stdout()| in headless usage.
---   -  - whether to stop execution (see |MiniTest.stop()|)
---     after first error. Default: `false`.
MiniTest.execute = function(cases, opts)
  H.check_type('cases', cases, 'table')

  MiniTest.current.all_cases = cases

  -- Verify correct arguments
  if #cases == 0 then
    H.message('No cases to execute.')
    return
  end

  opts = vim.tbl_deep_extend('force', H.get_config().execute, opts or {})
  local reporter = opts.reporter or (H.is_headless and MiniTest.gen_reporter.stdout() or MiniTest.gen_reporter.buffer())
  if type(reporter) ~= 'table' then
    H.message('`opts.reporter` should be table or `nil`.')
    return
  end
  opts.reporter = reporter

  -- Plan execution in order
  H.cache = { is_executing = true }

  local queue = {}
  table.insert(queue, function() H.exec_callable(reporter.start, cases) end)
  for case_num, cur_case in ipairs(cases) do
    table.insert(queue, H.make_case(cur_case, case_num, opts))
  end
  table.insert(queue, function() H.exec_callable(reporter.finish) end)
  -- - Use separate call to ensure that `reporter.finish` error won't interfere
  table.insert(queue, function() H.cache.is_executing = false end)

  -- Execute queue ensuring order
  -- NOTE: Directly `vim.schedule` each step without an explicit queue handling
  -- is possible, but it might interfere with async-adjacent yet synchronous
  -- functions (as `vim.wait()`) callsed inside cases outside of child process.
  local exec_queue_step, n_queue = function(_) end, #queue
  exec_queue_step = function(n)
    queue[n]()
    if n < n_queue then vim.schedule(function() exec_queue_step(n + 1) end) end
  end
  vim.schedule(function() exec_queue_step(1) end)
end

--- Stop test execution
---
---@param opts table|nil Options with fields:
---   -  - whether to close all child neovim processes
---     created with |MiniTest.new_child_neovim()|. Default: `true`.
MiniTest.stop = function(opts)
  opts = vim.tbl_deep_extend('force', { close_all_child_neovim = true }, opts or {})

  -- Register intention to stop execution
  H.cache.should_stop_execution = true

  -- Possibly stop all child Neovim processes
  if not opts.close_all_child_neovim then return end

  for _, child in ipairs(H.child_neovim_registry) do
    pcall(child.stop)
  end
  H.child_neovim_registry = {}
end

--- Check if tests are being executed
---
---@return boolean
MiniTest.is_executing = function() return H.cache.is_executing == true end

-- Expectations ---------------------------------------------------------------
--- Table with expectation functions
---
--- Each function has the following behavior:
--- - Silently returns `true` if expectation is fulfilled.
--- - Throws an informative error with information helpful for debugging.
---   Allows customizable fail reason to provide more context.
---
--- Mostly designed to be used within |mini.test| framework.
---
---@usage >lua
---   local x = 1 + 1
---   MiniTest.expect.equality(x, 2) -- passes
---   MiniTest.expect.equality(x, 1, { fail_reason = 'Not equal' }) -- fails
--- <
MiniTest.expect = {}

--- Expect equality of two objects
---
--- Equality is tested via |vim.deep_equal()|. It also tries to compute more
--- detailed cause for equality (for easier spotting the difference):
--- - If they have different types.
--- - For strings if they have different length or if some character is different.
--- - For tables it shows a "key branch" at which values are different along with
---   the actual values. A single difference is shown, there might be more.
---   For not nested tables key branch is just a key. If the difference is inside
---   nested tables, the key branch shows a "path through nested tables" to
---   a different value. Examples: >lua
---
---     local eq = MiniTest.expect.equality
---     eq({ 1, 2 }, { 1, 3 })         -- Key branch is `2`
---     eq({ 1, { 2 } }, { 1, 'c' })   -- Key branch is `2` ('c' is not a table)
---     eq({ 1, { 2 } }, { 1, { 3 } }) -- Key branch is `2->1`
---
---     -- Key branch is either `1->1->"a"` or `1->1->"b"`
---     eq({ { { a = 1 } } }, { { { b = 2 } } })
--- <
---@param left any First object.
---@param right any Second object.
---@param opts table|nil Options. Possible fields:
---   __test_expect_fail_reason
MiniTest.expect.equality = function(left, right, opts)
  if vim.deep_equal(left, right) then return true end

  opts = opts or {}
  local fail_reason = H.normalize_reason(opts.fail_reason, 'Failed expectation for equality', left, right)
  local cause = H.compute_no_equality_cause(left, right)
  local context = string.format('Cause: %s\nLeft:  %s\nRight: %s', cause, vim.inspect(left), vim.inspect(right))
  H.error_with_emphasis(fail_reason, context)
end

--- Expect no equality of two objects
---
--- Equality is tested via |vim.deep_equal()|.
---
---@param left any First object.
---@param right any Second object.
---@param opts table|nil Options. Possible fields:
---   __test_expect_fail_reason
MiniTest.expect.no_equality = function(left, right, opts)
  if not vim.deep_equal(left, right) then return true end

  opts = opts or {}
  local fail_reason = H.normalize_reason(opts.fail_reason, 'Failed expectation for *no* equality', left, right)
  local context = string.format('Object: %s', vim.inspect(left))
  H.error_with_emphasis(fail_reason, context)
end

--- Expect function call to raise error
---
---@param f function Function to be tested for raising error.
---@param pattern string|nil Pattern which error message should match.
---   Use `nil` or empty string to not test for pattern matching.
---@param opts table|nil Options. Possible fields:
---   __test_expect_fail_reason
MiniTest.expect.error = function(f, pattern, opts, ...)
  H.check_type('pattern', pattern, 'string', true)

  -- Provide backward compatibility for `(f, pattern, ...)` signature.
  -- TODO: Remove after releasing 'mini.nvim' 0.18.0
  local args = { ... }
  local is_valid_opts = type(opts) == 'table'
    and (opts.fail_reason == nil or type(opts.fail_reason) == 'string' or vim.is_callable(opts.fail_reason))
  if select('#', ...) > 0 or not (opts == nil or is_valid_opts) then
    table.insert(args, 1, opts)
    opts = {}
    vim.notify(
      '(mini.test) `expect.error` now does not accept extra arguments for tested function.'
        .. " It will mostly work until the next 'mini.nvim' release, but not after that."
        .. ' Use them explicitly inside anonymous function: `expect.error(f, "", 1, 2)` ->'
        .. ' `expect.error(function() f(1, 2) end, "")`.'
        .. '\nSorry for the inconvenience.',
      vim.log.levels.WARN
    )
  end
  local ok, err = pcall(f, unpack(args))

  err = tostring(err)
  local has_matched_error = not ok and string.find(err, pattern or '') ~= nil
  if has_matched_error then return true end

  opts = opts or {}
  local pattern_suffix = pattern == nil and '' or (' matching pattern ' .. vim.inspect(pattern))
  local fail_reason = H.normalize_reason(opts.fail_reason, 'Failed expectation for error' .. pattern_suffix, f, pattern)
  local context = ok and 'Observed no error' or ('Observed error: ' .. err)
  H.error_with_emphasis(fail_reason, context)
end

--- Expect function call to not raise error
---
---@param f function Function to be tested for not raising error.
---@param opts table|nil Options. Possible fields:
---   __test_expect_fail_reason
MiniTest.expect.no_error = function(f, opts, ...)
  -- Provide backward compatibility for `(f, ...)` signature.
  -- TODO: Remove after releasing 'mini.nvim' 0.18.0
  local args = { ... }
  local is_valid_opts = type(opts) == 'table' and (opts.fail_prefix == nil or type(opts.fail_prefix) == 'string')
  if select('#', ...) > 0 or not (opts == nil or is_valid_opts) then
    table.insert(args, 1, opts)
    opts = {}
    vim.notify(
      '(mini.test) `expect.no_error` now does not accept extra arguments for tested function.'
        .. " It will mostly work until the next 'mini.nvim' release, but not after that."
        .. ' Use them explicitly inside anonymous function: `expect.no_error(f, 1, 2)` ->'
        .. ' `expect.no_error(function() f(1, 2) end)`.'
        .. '\nSorry for the inconvenience.',
      vim.log.levels.WARN
    )
  end
  local ok, err = pcall(f, unpack(args))
  if ok then return true end

  opts = opts or {}
  local fail_reason = H.normalize_reason(opts.fail_reason, 'Failed expectation for *no* error', f)
  H.error_with_emphasis(fail_reason, 'Observed error: ' .. tostring(err))
end

--- Expect equality to reference screenshot
---
---@param screenshot table|nil Array with screenshot information. Usually an output
---   of `child.get_screenshot()` (see |MiniTest-child-neovim-get_screenshot()|).
---   If `nil`, expectation passed.
---@param path string|nil Path to reference screenshot. If `nil`, constructed
---   automatically in directory `opts.directory` from current case info and
---   total number of times it was called inside current case. If there is no
---   file at `path`, it is created with content of `screenshot`.
---@param opts table|nil Options:
---   -  `(boolean)` - whether to forcefully create reference screenshot.
---     Temporary useful during test writing. Default: `false`.
---   -  `(boolean|table)` - whether to ignore all or some text lines.
---     If `true` - ignore all, if number array - ignore text of those lines,
---     if `false` - do not ignore any. Default: `false`.
---   -  `(boolean|table)` - whether to ignore all or some attr lines.
---     If `true` - ignore all, if number array - ignore attr of those lines,
---     if `false` - do not ignore any. Default: `false`.
---   -  `(string)` - directory where automatically constructed `path`
---     is located. Default: "tests/screenshots".
---   __test_expect_fail_reason
MiniTest.expect.reference_screenshot = function(screenshot, path, opts)
  if screenshot == nil then return true end

  local default_opts = { force = false, ignore_text = false, ignore_attr = false, directory = 'tests/screenshots' }
  opts = vim.tbl_extend('force', default_opts, opts or {})

  H.cache.n_screenshots = H.cache.n_screenshots + 1

  if path == nil then
    -- Sanitize path. Replace any control characters, whitespace, OS specific
    -- forbidden characters with '-' (with some useful exception)
    local linux_forbidden = [[/]]
    local windows_forbidden = [[<>:"/\|?*]]
    local pattern = string.format('[%%c%%s%s%s]', vim.pesc(linux_forbidden), vim.pesc(windows_forbidden))
    local replacements = setmetatable({ ['"'] = "'" }, { __index = function() return '-' end })
    local name = H.case_to_stringid(MiniTest.current.case):gsub(pattern, replacements)

    -- Don't end with whitespace or dot (forbidden on Windows)
    name = name:gsub('[%s%.]$', '-')
    path = vim.fs.normalize(opts.directory) .. '/' .. name

    -- Deal with multiple screenshots
    if H.cache.n_screenshots > 1 then path = path .. string.format('-%03d', H.cache.n_screenshots) end
  end

  -- If there is no readable screenshot file, create it. Pass with note.
  if opts.force or vim.fn.filereadable(path) == 0 then
    local dir_path = vim.fn.fnamemodify(path, ':p:h')
    vim.fn.mkdir(dir_path, 'p')
    H.screenshot_write(screenshot, path)

    MiniTest.add_note('Created reference screenshot at path ' .. vim.inspect(path))
    return true
  end

  local reference = H.screenshot_read(path)

  -- Compare
  local same_text, cause_text = H.screenshot_compare_part('text', reference, screenshot, opts)
  local same_attr, cause_attr = H.screenshot_compare_part('attr', reference, screenshot, opts)
  if same_text and same_attr then return true end

  local fail_reason_fallback = 'Failed expectation for screenshot equality to reference at ' .. vim.inspect(path)
  local fail_reason = H.normalize_reason(opts.fail_reason, fail_reason_fallback, screenshot, path)
  local cause = same_text and cause_attr or cause_text
  local context = string.format('%s\nReference:\n%s\n\nObserved:\n%s', cause, tostring(reference), tostring(screenshot))
  H.error_with_emphasis(fail_reason, context)
end

--- Create new expectation function
---
--- Helper for writing custom functions with behavior similar to other methods
--- of |MiniTest.expect|.
---
---@param subject string|function|table Subject of expectation. If callable,
---   called with expectation input arguments to produce string value.
---@param predicate function|table Predicate callable. Called with expectation
---   input arguments. Output `false` or `nil` means failed expectation.
---@param fail_context string|function|table Information about fail. If callable,
---   called with expectation input arguments to produce string value.
---
---@return function Expectation function.
---
---@usage >lua
---   local expect_truthy = MiniTest.new_expectation(
---     'truthy',
---     function(x) return x end,
---     function(x) return 'Object: ' .. vim.inspect(x) end
---   )
--- <
MiniTest.new_expectation = function(subject, predicate, fail_context)
  return function(...)
    if predicate(...) then return true end

    local cur_subject = vim.is_callable(subject) and subject(...) or subject
    local cur_context = vim.is_callable(fail_context) and fail_context(...) or fail_context
    H.error_with_emphasis('Failed expectation for ' .. cur_subject, cur_context)
  end
end

-- Reporters ------------------------------------------------------------------
--- Table with pre-configured report generators
---
--- Each element is a function which returns reporter - table with callable
--- `start`, `update`, and `finish` fields.
MiniTest.gen_reporter = {}

--- Generate buffer reporter
---
--- This is a default choice for interactive (not headless) usage. Opens a window
--- with dedicated non-terminal buffer and updates it with throttled redraws.
---
--- Opened buffer has the following helpful Normal mode mappings:
--- - `` - stop test execution if executing (see |MiniTest.is_executing()|
---   and |MiniTest.stop()|). Close window otherwise.
--- - `q` - same as `` for convenience and compatibility.
---
--- General idea:
--- - Group cases by concatenating first `opts.group_depth` elements of case
---   description (`desc` field). Groups by collected files if using default values.
--- - In `start()` show some stats to know how much is scheduled to be executed.
--- - In `update()` show symbolic overview of current group and state of current
---   case. Each symbol represents one case and its state:
---     - `?` - case didn't finish executing.
---     - `o` - pass.
---     - `O` - pass with notes.
---     - `x` - fail.
---     - `X` - fail with notes.
--- - In `finish()` show all fails and notes ordered by case.
---
---@param opts table|nil Table with options. Used fields:
---   -  - number of first elements of case description (can be zero)
---     used for grouping. Higher values mean higher granularity of output.
---     Default: 1.
---   -  - minimum number of milliseconds to wait between
---     redrawing. Reduces screen flickering but not amount of computations.
---     Default: 10.
---   -  - definition of window to open. Can take one of the forms:
---       - Callable. It is called expecting output to be target window id
---         (current window is used if output is `nil`). Use this to open in
---         "normal" window (like `function() vim.cmd('vsplit') end`).
---       - Table. Used as `config` argument in |nvim_open_win()|.
---     Default: table for centered floating window.
MiniTest.gen_reporter.buffer = function(opts)
  -- NOTE: another choice of implementing this is to use terminal buffer
  -- `vim.api.nvim_open_term()`.
  -- Pros:
  -- - Renders ANSI escape sequences (mostly) correctly, i.e. no need in
  --   replacing them with Neovim range highlights.
  -- - This reporter and `stdout` one can share more of a codebase.
  -- Cons:
  -- - Couldn't manage to implement "redraw on every update".
  -- - Extra steps still are needed in order to have richer output information.
  --   This involves ANSI sequences that move cursor, which have same issues as
  --   in `stdout`, albeit easier to overcome:
  --     - Handling of scroll.
  --     - Hard wrapping of lines leading to need of using window width.
  local default_opts = { group_depth = 1, throttle_delay = 10, window = H.buffer_reporter.default_window_opts() }
  opts = vim.tbl_deep_extend('force', default_opts, opts or {})

  local buf_id, win_id
  local is_valid_buf_win = function() return vim.api.nvim_buf_is_valid(buf_id) and vim.api.nvim_win_is_valid(win_id) end

  -- Helpers
  local set_cursor = function(line)
    vim.api.nvim_win_set_cursor(win_id, { line or vim.api.nvim_buf_line_count(buf_id), 0 })
  end

  -- Define "write from cursor line" function with throttled redraw
  local latest_draw_time = 0
  local replace_last = function(n_replace, lines, force)
    H.buffer_reporter.set_lines(buf_id, lines, -n_replace - 1, -1)

    -- Throttle redraw to reduce flicker
    local cur_time = vim.loop.hrtime()
    local is_enough_time_passed = (cur_time - latest_draw_time) > opts.throttle_delay * 1000000
    if is_enough_time_passed or force then
      vim.cmd('redraw')
      latest_draw_time = cur_time
    end
  end

  -- Create reporter functions
  local res = {}
  local all_cases, all_groups, latest_group_name

  res.start = function(cases)
    -- Set up buffer and window
    buf_id, win_id = H.buffer_reporter.setup_buf_and_win(opts.window)

    -- Set up data (taking into account possible not first time run)
    all_cases = cases
    all_groups = H.overview_reporter.compute_groups(cases, opts.group_depth)
    latest_group_name = nil

    -- Write lines
    local lines = H.overview_reporter.start_lines(all_cases, all_groups)
    replace_last(1, lines)
    set_cursor()
  end

  res.update = function(case_num)
    if not is_valid_buf_win() then return end

    local case, cur_group_name = all_cases[case_num], all_groups[case_num].name

    -- Update symbol
    local state = type(case.exec) == 'table' and case.exec.state or nil
    all_groups[case_num].symbol = H.reporter_symbols[state]

    local n_replace = H.buffer_reporter.update_step_n_replace(latest_group_name, cur_group_name)
    local lines = H.buffer_reporter.update_step_lines(case_num, all_cases, all_groups)
    replace_last(n_replace, lines)
    set_cursor()

    latest_group_name = cur_group_name
  end

  res.finish = function()
    if not is_valid_buf_win() then return end

    -- Cache final cursor position to overwrite 'Current case state' header
    local start_line = vim.api.nvim_buf_line_count(buf_id) - 1

    -- Force writing lines
    local lines = H.overview_reporter.finish_lines(all_cases)
    replace_last(2, lines, true)
    set_cursor(start_line)
  end

  return res
end

--- Generate stdout reporter
---
--- This is a default choice for headless usage. Writes to `stdout`. Uses
--- coloring ANSI escape sequences to make pretty and informative output
--- (should work in most modern terminals and continuous integration providers).
---
--- It has same general idea as |MiniTest.gen_reporter.buffer()| with slightly
--- less output (it doesn't overwrite previous text) to overcome typical
--- terminal limitations.
---
---@param opts table|nil Table with options. Used fields:
---   -  - number of first elements of case description (can be zero)
---     used for grouping. Higher values mean higher granularity of output.
---     Default: 1.
---   -  - whether to quit after finishing test execution.
---     Default: `true`.
MiniTest.gen_reporter.stdout = function(opts)
  opts = vim.tbl_deep_extend('force', { group_depth = 1, quit_on_finish = true }, opts or {})

  local write = function(text)
    text = type(text) == 'table' and table.concat(text, '\n') or text
    io.stdout:write(text)
    io.flush()
  end

  local all_cases, all_groups, latest_group_name
  local default_symbol = H.reporter_symbols[nil]

  local res = {}

  res.start = function(cases)
    -- Set up data
    all_cases = cases
    all_groups = H.overview_reporter.compute_groups(cases, opts.group_depth)

    -- Write lines
    local lines = H.overview_reporter.start_lines(all_cases, all_groups)
    write(lines)
  end

  res.update = function(case_num)
    local cur_case = all_cases[case_num]
    local cur_group_name = all_groups[case_num].name

    -- Possibly start overview of new group
    if cur_group_name ~= latest_group_name then
      write('\n')
      write(cur_group_name)
      if cur_group_name ~= '' then write(': ') end
    end

    -- Possibly show new symbol
    local state = type(cur_case.exec) == 'table' and cur_case.exec.state or nil
    local cur_symbol = H.reporter_symbols[state]
    if cur_symbol ~= default_symbol then write(cur_symbol) end

    latest_group_name = cur_group_name
  end

  res.finish = function()
    write('\n\n')
    local lines = H.overview_reporter.finish_lines(all_cases)
    write(lines)
    write('\n')

    -- Possibly quit
    if not opts.quit_on_finish then return end
    local command = string.format('silent! %scquit', H.has_fails(all_cases) and 1 or 0)
    vim.cmd(command)
  end

  return res
end

-- Exported utility functions -------------------------------------------------
--- Create child Neovim process
---
--- This creates an object designed to be a fundamental piece of |mini.test|
--- methodology. It can start/stop/restart a separate (child) Neovim process
--- (headless, but fully functioning) together with convenience helpers to
--- interact with it through |RPC| messages.
---
--- For more information see |MiniTest-child-neovim|.
---
---@return MiniTest.child Object of |MiniTest-child-neovim|.
---
---@usage >lua
---   -- Initiate
---   local child = MiniTest.new_child_neovim()
---   child.start()
---
---   -- Use API functions
---   child.api.nvim_buf_set_lines(0, 0, -1, true, { 'Line inside child Neovim' })
---
---   -- Execute Lua code, Vimscript commands, etc.
---   child.lua('_G.n = 0')
---   child.cmd('au CursorMoved * lua _G.n = _G.n + 1')
---   child.type_keys('l')
---   print(child.lua_get('_G.n')) -- Should be 1
---
---   -- Use other `vim.xxx` Lua wrappers (executed inside child process)
---   vim.b.aaa = 'current process'
---   child.b.aaa = 'child process'
---   print(child.lua_get('vim.b.aaa')) -- Should be 'child process'
---
---   -- Always stop process after it is not needed
---   child.stop()
--- <
MiniTest.new_child_neovim = function()
  local child = {}
  local start_args, start_opts

  local ensure_running = function()
    if child.is_running() then return end
    H.error('Child process is not running. Did you call `child.start()`?')
  end

  local prevent_hanging = function(method)
    if not child.is_blocked() then return end

    local msg = string.format('Can not use `child.%s` because child process is blocked.', method)
    H.error_with_emphasis(msg)
  end

  -- Start headless Neovim instance
  child.start = function(args, opts)
    if child.is_running() then
      H.message('Child process is already running. Use `child.restart()`.')
      return
    end

    args = args or {}
    opts = vim.tbl_deep_extend('force', { nvim_executable = vim.v.progpath, connection_timeout = 5000 }, opts or {})

    -- Make unique name for `--listen` pipe
    local job = { address = vim.fn.tempname() }

    if vim.fn.has('win32') == 1 then
      -- Use special local pipe prefix on Windows with (hopefully) unique name
      -- Source: https://learn.microsoft.com/en-us/windows/win32/ipc/pipe-names
      job.address = [[\\.\pipe\mininvim]] .. vim.fn.fnamemodify(job.address, ':t')
    end

    --stylua: ignore
    local full_args = {
      opts.nvim_executable, '--clean', '-n', '--listen', job.address,
      -- Setting 'lines' and 'columns' makes headless process more like
      -- interactive for closer to reality testing
      '--headless', '--cmd', 'set lines=24 columns=80'
    }
    vim.list_extend(full_args, args)

    -- Using 'jobstart' for creating a job is crucial for getting this to work
    -- in Github Actions. Other approaches:
    -- - Using `{ pty = true }` seems crucial to make this work on GitHub CI.
    -- - Using `vim.loop.spawn()` is doable, but has some issues:
    --     - https://github.com/neovim/neovim/issues/21630
    --     - https://github.com/neovim/neovim/issues/21886
    job.id = vim.fn.jobstart(full_args)

    local step = 10
    local connected, i, max_tries = nil, 0, math.floor(opts.connection_timeout / step)
    repeat
      i = i + 1
      vim.loop.sleep(step)
      connected, job.channel = pcall(vim.fn.sockconnect, 'pipe', job.address, { rpc = true })
    until connected or i >= max_tries

    if not connected then
      local err = '  ' .. job.channel:gsub('\n', '\n  ')
      H.error('Failed to make connection to child Neovim with the following error:\n' .. err)
      child.stop()
    end

    child.job = job
    start_args, start_opts = args, opts
  end

  child.stop = function()
    if not child.is_running() then return end

    -- Properly exit Neovim. `pcall` avoids `channel closed by client` error.
    -- Also wait for it to actually close. This reduces simultaneously opened
    -- Neovim instances and CPU load (overall reducing flacky tests).
    pcall(child.cmd, 'silent! 0cquit')
    vim.fn.jobwait({ child.job.id }, 1000)

    -- Close all used channels. Prevents `too many open files` type of errors.
    pcall(vim.fn.chanclose, child.job.channel)
    pcall(vim.fn.chanclose, child.job.id)

    -- Remove file for address to reduce chance of "can't open file" errors, as
    -- address uses temporary unique files
    pcall(vim.fn.delete, child.job.address)

    child.job = nil
  end

  child.restart = function(args, opts)
    args = args or start_args
    opts = vim.tbl_deep_extend('force', start_opts or {}, opts or {})

    child.stop()
    child.start(args, opts)
  end

  -- Wrappers for common `vim.xxx` objects (will get executed inside child)
  child.api = setmetatable({}, {
    __index = function(_, key)
      ensure_running()
      return function(...) return vim.rpcrequest(child.job.channel, key, ...) end
    end,
  })

  -- Variant of `api` functions called with `vim.rpcnotify`. Useful for making
  -- blocking requests (like `getcharstr()`).
  child.api_notify = setmetatable({}, {
    __index = function(_, key)
      ensure_running()
      return function(...) return vim.rpcnotify(child.job.channel, key, ...) end
    end,
  })

  ---@return table Emulates `vim.xxx` table (like `vim.fn`)
  ---@private
  local redirect_to_child = function(tbl_name)
    -- TODO: try to figure out the best way to operate on tables with function
    -- values (needs "deep encode/decode" of function objects)
    return setmetatable({}, {
      __index = function(_, key)
        ensure_running()

        local short_name = ('%s.%s'):format(tbl_name, key)
        local obj_name = ('vim[%s][%s]'):format(vim.inspect(tbl_name), vim.inspect(key))

        prevent_hanging(short_name)
        local value_type = child.api.nvim_exec_lua(('return type(%s)'):format(obj_name), {})

        if value_type == 'function' then
          -- This allows syntax like `child.fn.mode(1)`
          return function(...)
            prevent_hanging(short_name)
            return child.api.nvim_exec_lua(('return %s(...)'):format(obj_name), { ... })
          end
        end

        -- This allows syntax like `child.bo.buftype`
        prevent_hanging(short_name)
        return child.api.nvim_exec_lua(('return %s'):format(obj_name), {})
      end,
      __newindex = function(_, key, value)
        ensure_running()

        local short_name = ('%s.%s'):format(tbl_name, key)
        local obj_name = ('vim[%s][%s]'):format(vim.inspect(tbl_name), vim.inspect(key))

        -- This allows syntax like `child.b.aaa = function(x) return x + 1 end`
        -- (inherits limitations of `string.dump`: no upvalues, etc.)
        if type(value) == 'function' then
          local dumped = vim.inspect(string.dump(value))
          value = ('loadstring(%s)'):format(dumped)
        else
          value = vim.inspect(value)
        end

        prevent_hanging(short_name)
        child.api.nvim_exec_lua(('%s = %s'):format(obj_name, value), {})
      end,
    })
  end

  --stylua: ignore start
  local supported_vim_tables = {
    -- Collections
    'diagnostic', 'fn', 'highlight', 'hl', 'json', 'loop', 'lsp', 'mpack', 'spell', 'treesitter', 'ui', 'fs',
    -- Variables
    'g', 'b', 'w', 't', 'v', 'env',
    -- Options (no 'opt' because not really useful due to use of metatables)
    'o', 'go', 'bo', 'wo',
  }
  --stylua: ignore end
  for _, v in ipairs(supported_vim_tables) do
    child[v] = redirect_to_child(v)
  end

  -- Convenience wrappers
  child.type_keys = function(wait, ...)
    ensure_running()

    local has_wait = type(wait) == 'number'
    local keys = has_wait and { ... } or { wait, ... }
    keys = H.tbl_flatten(keys)

    -- From `nvim_input` docs: "On execution error: does not fail, but
    -- updates v:errmsg.". So capture it manually. NOTE: Have it global to
    -- allow sending keys which will block in the middle (like `[[]]` and
    -- ``). Otherwise, later check will assume that there was an error.
    local cur_errmsg
    for _, k in ipairs(keys) do
      if type(k) ~= 'string' then
        error('In `type_keys()` each argument should be either string or array of strings.')
      end

      -- But do that only if Neovim is not "blocked". Otherwise, usage of
      -- `child.v` will block execution.
      if not child.is_blocked() then
        cur_errmsg = child.v.errmsg
        child.v.errmsg = ''
      end

      -- Need to escape bare `<` (see `:h nvim_input`)
      child.api.nvim_input(k == '<' and '' or k)

      -- Possibly throw error manually
      if not child.is_blocked() then
        if child.v.errmsg ~= '' then
          error(child.v.errmsg, 2)
        else
          child.v.errmsg = cur_errmsg or ''
        end
      end

      -- Possibly wait
      if has_wait and wait > 0 then vim.loop.sleep(wait) end
    end
  end

  child.cmd = function(str)
    ensure_running()
    prevent_hanging('cmd')
    return child.api.nvim_exec(str, false)
  end

  child.cmd_capture = function(str)
    ensure_running()
    prevent_hanging('cmd_capture')
    return child.api.nvim_exec(str, true)
  end

  child.lua = function(str, args)
    ensure_running()
    prevent_hanging('lua')
    return child.api.nvim_exec_lua(str, args or {})
  end

  child.lua_notify = function(str, args)
    ensure_running()
    return child.api_notify.nvim_exec_lua(str, args or {})
  end

  child.lua_get = function(str, args)
    ensure_running()
    prevent_hanging('lua_get')
    return child.api.nvim_exec_lua('return ' .. str, args or {})
  end

  child.lua_func = function(f, ...)
    ensure_running()
    prevent_hanging('lua_func')
    return child.api.nvim_exec_lua(
      'local f = ...; return assert(loadstring(f))(select(2, ...))',
      { string.dump(f), ... }
    )
  end

  child.is_blocked = function()
    ensure_running()
    return child.api.nvim_get_mode()['blocking']
  end

  child.is_running = function() return child.job ~= nil end

  -- Various wrappers
  child.ensure_normal_mode = function()
    ensure_running()
    child.type_keys([[]], '')
  end

  child.get_screenshot = function(opts)
    ensure_running()
    prevent_hanging('get_screenshot')

    opts = vim.tbl_deep_extend('force', { redraw = true }, opts or {})

    if opts.redraw then child.cmd('redraw') end

    local res = child.lua([[
      local text, attr = {}, {}
      for i = 1, vim.o.lines do
        local text_line, attr_line = {}, {}
        for j = 1, vim.o.columns do
          table.insert(text_line, vim.fn.screenstring(i, j))
          table.insert(attr_line, vim.fn.screenattr(i, j))
        end
        table.insert(text, text_line)
        table.insert(attr, attr_line)
      end
      return { text = text, attr = attr }
    ]])
    res.attr = H.screenshot_encode_attr(res.attr)

    return H.screenshot_new(res)
  end

  -- Register `child` for automatic stop in case of emergency
  table.insert(H.child_neovim_registry, child)

  return child
end

--- Child class
---
--- It offers a great set of tools to write reliable and reproducible tests by
--- allowing to use fresh process in any test action. Interaction with it is done
--- through |RPC| protocol.
---
--- Although quite flexible, at the moment it has certain limitations:
--- - Doesn't allow using functions or userdata for child's both inputs and
---   outputs. Usual solution is to move computations from current Neovim process
---   to child process. Use `child.lua()` and `child.lua_get()` for that.
--- - When writing tests, it is common to end up with "hanging" process: it
---   stops executing without any output. Most of the time it is because Neovim
---   process is "blocked", i.e. it waits for user input and won't return from
---   other call (like `child.api.nvim_exec_lua()`). Common causes are active
---   |hit-enter-prompt| (increase prompt height to a bigger value) or
---   Operator-pending mode (exit it). To mitigate this experience, most helpers
---   will throw an error if its immediate execution will lead to hanging state.
---   Also in case of hanging state try `child.api_notify` instead of `child.api`.
---
--- Notes:
--- - An important type of field is a "redirection table". It acts as a
---   convenience wrapper for corresponding `vim.*` table. Can be used both to
---   return and set values. Examples:
---     - `child.api.nvim_buf_line_count(0)` will execute
---       `vim.api.nvim_buf_line_count(0)` inside child process and return its
---       output to current process.
---     - `child.bo.filetype = 'lua'` will execute `vim.bo.filetype = 'lua'`
---       inside child process.
---   They still have same limitations listed above, so are not perfect. In
---   case of a doubt, use `child.lua()`.
--- - Almost all methods use |vim.rpcrequest()| (i.e. wait for call to finish and
---   then return value). See for `*_notify` variant to use |vim.rpcnotify()|.
--- - All fields and methods should be called with `.`, not `:`.
---
---@class MiniTest.child
---
---@field start function Start child process. See |MiniTest-child-neovim-start()|.
---@field stop function Stop current child process.
---@field restart function Restart child process: stop if running and then
---   start a new one. Takes same arguments as `child.start()` but uses values
---   from most recent `start()` call as defaults.
---
---@field type_keys function Emulate typing keys.
---   See |MiniTest-child-neovim-type_keys()|. Doesn't check for blocked state.
---
---@field cmd function Execute Vimscript code from a string.
---   A wrapper for |nvim_exec()| without capturing output.
---@field cmd_capture function Execute Vimscript code from a string and
---   capture output. A wrapper for |nvim_exec()| with capturing output.
---
---@field lua function Execute Lua code. A wrapper for |nvim_exec_lua()|.
---@field lua_notify function Execute Lua code without waiting for output.
---@field lua_get function Execute Lua code and return result. A wrapper
---   for |nvim_exec_lua()| but prepends string code with `return`.
---@field lua_func function Execute Lua function and return it's result.
---   Function will be called with all extra parameters (second one and later).
---   Note: usage of upvalues (data from outside function scope) is not allowed.
---
---@field is_blocked function Check whether child process is blocked.
---@field is_running function Check whether child process is currently running.
---
---@field ensure_normal_mode function Ensure normal mode.
---@field get_screenshot function Returns table with two "2d arrays" of single
---   characters representing what is displayed on screen and how it looks.
---   Has `opts` table argument for optional configuratnion.
---
---@field job table|nil Information about current job. If `nil`, child is not running.
---
---@field api table Redirection table for `vim.api`. Doesn't check for blocked state.
---@field api_notify table Same as `api`, but uses |vim.rpcnotify()|.
---
---@field diagnostic table Redirection table for |vim.diagnostic|.
---@field fn table Redirection table for |vim.fn|.
---@field highlight table Redirection table for |vim.highlight|.
---@field hl table Redirection table for |vim.hl|.
---@field json table Redirection table for `vim.json`.
---@field loop table Redirection table for |vim.loop|.
---@field lsp table Redirection table for `vim.lsp` (|lsp-core|).
---@field mpack table Redirection table for |vim.mpack|.
---@field spell table Redirection table for |vim.spell|.
---@field treesitter table Redirection table for `vim.treesitter` (|lua-treesitter-core|).
---@field ui table Redirection table for |vim.ui|. Currently of no
---   use because it requires sending function through RPC, which is impossible
---   at the moment.
---@field fs table Redirection table for |vim.fs|.
---
---@field g table Redirection table for |vim.g|.
---@field b table Redirection table for |vim.b|.
---@field w table Redirection table for |vim.w|.
---@field t table Redirection table for |vim.t|.
---@field v table Redirection table for |vim.v|.
---@field env table Redirection table for |vim.env|.
---
---@field o table Redirection table for |vim.o|.
---@field go table Redirection table for |vim.go|.
---@field bo table Redirection table for |vim.bo|.
---@field wo table Redirection table for |vim.wo|.
---@tag MiniTest-child-neovim

---                           `child.start`({args}, {opts})
---
--- Start child process and connect to it. Won't work if child is already running.
---
---@param args table Array with arguments for executable. Will be prepended with
---   the following default arguments (see |startup-options|): >lua
---   { '--clean', '-n', '--listen', ,
---     '--headless', '--cmd', 'set lines=24 columns=80' }
--- <
---@param opts table|nil Options:
---   -  - name of Neovim executable. Default: |v:progpath|.
---   -  - stop trying to connect after this amount of
---     milliseconds. Default: 5000.
---
---@usage >lua
---   child = MiniTest.new_child_neovim()
---
---   -- Start default clean Neovim instance
---   child.start()
---
---   -- Start with custom 'init.lua' file
---   child.start({ '-u', 'scripts/minimal_init.lua' })
--- <
---@tag MiniTest-child-neovim-start()

---                        `child.type_keys`({wait}, {...})
---
--- Basically a wrapper for |nvim_input()| applied inside child process.
--- Differences:
--- - Can wait after each group of characters.
--- - Raises error if typing keys resulted into error in child process (i.e. its
---   |v:errmsg| was updated).
--- - Key `<` as a separate entry may not be escaped as ``.
---
---@param wait number|nil Number of milliseconds to wait after each entry. May be
---   omitted, in which case no waiting is done.
---@param ... string|table Separate entries for |nvim_input()|,
---   after which `wait` will be applied. Can be either string or array of strings.
---
---@usage >lua
---   -- All of these type keys 'c', 'a', 'w'
---   child.type_keys('caw')
---   child.type_keys('c', 'a', 'w')
---   child.type_keys('c', { 'a', 'w' })
---
---   -- Waits 5 ms after `c` and after 'w'
---   child.type_keys(5, 'c', { 'a', 'w' })
---
---   -- Special keys can also be used
---   child.type_keys('i', 'Hello world', '')
--- <
---@tag MiniTest-child-neovim-type_keys()

---                         `child.get_screenshot`({opts})
---
--- Compute what is displayed on (default TUI) screen and how it is displayed.
--- This basically calls |screenstring()| and |screenattr()| for every visible
--- cell (row from 1 to |'lines'|, column from 1 to |'columns'|).
---
--- Notes:
--- - To make output more portable and visually useful, outputs of
---   `screenattr()` are coded with single character symbols. Those are taken from
---   94 characters (ASCII codes between 33 and 126), so there will be duplicates
---   in case of more than 94 different ways text is displayed on screen.
---
---@param opts table|nil Options. Possieble fields:
---   -  `(boolean)` - whether to call |:redraw| prior to computing
---     screenshot. Default: `true`.
---
---@return table|nil Screenshot table with the following fields:
---   -  - "2d array" (row-column) of single characters displayed at
---     particular cells.
---   -  - "2d array" (row-column) of symbols representing how text is
---     displayed (basically, "coded" appearance/highlighting). They should be
---     used only in relation to each other: same/different symbols for two
---     cells mean same/different visual appearance. Note: there will be false
---     positives if there are more than 94 different attribute values.
---   It also can be used with `tostring()` to convert to single string (used
---   for writing to reference file). It results into two visual parts
---   (separated by empty line), for `text` and `attr`. Each part has "ruler"
---   above content and line numbers for each line.
---   Returns `nil` if couldn't get a reasonable screenshot.
---
---@usage >lua
---   local screenshot = child.get_screenshot()
---
---   -- Show character displayed row=3 and column=4
---   print(screenshot.text[3][4])
---
---   -- Convert to string
---   tostring(screenshot)
--- <
---@tag MiniTest-child-neovim-get_screenshot()

-- Helper data ================================================================
-- Module default config
H.default_config = vim.deepcopy(MiniTest.config)

-- Whether instance is running in headless mode
H.is_headless = #vim.api.nvim_list_uis() == 0

-- Cache for various data
H.cache = {
  -- Message with which case is meant to be skipped
  skip_message = nil,
  -- Queue of callables to be executed after step (hook or test function)
  finally = {},
  -- Whether to stop async execution
  should_stop_execution = false,
  -- Number of screenshots made in current case
  n_screenshots = 0,
}

-- Registry of all Neovim child processes
H.child_neovim_registry = {}

-- ANSI codes for common cases
H.ansi_codes = {
  fail = '\27[1;31m', -- Bold red
  pass = '\27[1;32m', -- Bold green
  emphasis = '\27[1m', -- Bold
  reset = '\27[0m',
}

-- Highlight groups for common ANSI codes
H.hl_groups = {
  ['\27[1;31m'] = 'MiniTestFail',
  ['\27[1;32m'] = 'MiniTestPass',
  ['\27[1m'] = 'MiniTestEmphasis',
}

-- Symbols used in reporter output
--stylua: ignore
H.reporter_symbols = setmetatable({
  ['Pass']            = H.ansi_codes.pass .. 'o' .. H.ansi_codes.reset,
  ['Pass with notes'] = H.ansi_codes.pass .. 'O' .. H.ansi_codes.reset,
  ['Fail']            = H.ansi_codes.fail .. 'x' .. H.ansi_codes.reset,
  ['Fail with notes'] = H.ansi_codes.fail .. 'X' .. H.ansi_codes.reset,
}, {
  __index = function() return H.ansi_codes.emphasis .. '?' .. H.ansi_codes.reset end,
})

-- Helper functionality =======================================================
-- Settings -------------------------------------------------------------------
H.setup_config = function(config)
  H.check_type('config', config, 'table', true)
  config = vim.tbl_deep_extend('force', vim.deepcopy(H.default_config), config or {})

  H.check_type('collect', config.collect, 'table')
  H.check_type('collect.emulate_busted', config.collect.emulate_busted, 'boolean')
  H.check_type('collect.find_files', config.collect.find_files, 'function')
  H.check_type('collect.filter_cases', config.collect.filter_cases, 'function')

  H.check_type('execute', config.execute, 'table')
  H.check_type('execute.reporter', config.execute.reporter, 'table', true)
  H.check_type('execute.stop_on_error', config.execute.stop_on_error, 'boolean')

  H.check_type('script_path', config.script_path, 'string')
  H.check_type('silent', config.silent, 'boolean')

  return config
end

H.apply_config = function(config) MiniTest.config = config end

H.create_autocommands = function()
  local gr = vim.api.nvim_create_augroup('MiniTest', {})
  vim.api.nvim_create_autocmd('ColorScheme', { group = gr, callback = H.create_default_hl, desc = 'Ensure colors' })
end

H.create_default_hl = function()
  local set_default_hl = function(name, data)
    data.default = true
    vim.api.nvim_set_hl(0, name, data)
  end

  set_default_hl('MiniTestFail', { fg = vim.g.terminal_color_1 or '#FF0000', bold = true })
  set_default_hl('MiniTestPass', { fg = vim.g.terminal_color_2 or '#00FF00', bold = true })
  set_default_hl('MiniTestEmphasis', { bold = true })
end

H.is_disabled = function() return vim.g.minitest_disable == true or vim.b.minitest_disable == true end

H.get_config = function(config)
  return vim.tbl_deep_extend('force', MiniTest.config, vim.b.minitest_config or {}, config or {})
end

-- Work with collection -------------------------------------------------------
H.busted_emulate = function(set)
  local cur_set = set

  _G.describe = function(name, f)
    local cur_set_parent = cur_set
    cur_set_parent[name] = MiniTest.new_set()
    cur_set = cur_set_parent[name]
    f()
    cur_set = cur_set_parent
  end

  _G.it = function(name, f) cur_set[name] = f end

  local setting_hook = function(hook_name)
    return function(hook)
      local metatbl = getmetatable(cur_set)
      metatbl.opts.hooks = metatbl.opts.hooks or {}
      metatbl.opts.hooks[hook_name] = hook
    end
  end

  _G.setup = setting_hook('pre_once')
  _G.before_each = setting_hook('pre_case')
  _G.after_each = setting_hook('post_case')
  _G.teardown = setting_hook('post_once')
end

H.busted_deemulate = function()
  local fun_names = { 'describe', 'it', 'setup', 'before_each', 'after_each', 'teardown' }
  for _, f_name in ipairs(fun_names) do
    _G[f_name] = nil
  end
end

-- Work with execution --------------------------------------------------------
H.execute_project_script = function(...)
  -- Don't process script if there are more than one active `run` calls
  if H.is_inside_script then return false end

  -- Don't process script if at least one argument is not default (`nil`)
  if #{ ... } > 0 then return end

  -- Store information
  local config_cache = vim.deepcopy(MiniTest.config)
  local local_config_cache = vim.b.minitest_config

  -- Pass information to a possible `run()` call inside script
  H.is_inside_script = true

  -- Execute script
  local success = pcall(vim.cmd, 'luafile ' .. H.get_config().script_path)

  -- Restore information
  MiniTest.config = config_cache
  vim.b.minitest_config = local_config_cache
  H.is_inside_script = nil

  return success
end

H.make_case = function(case, case_num, opts)
  local update_state = function(state)
    case.exec.state = state
    H.exec_callable(opts.reporter.update, case_num)
  end

  local is_case_executed = false
  local on_err = function(e)
    if H.cache.skip_message ~= nil then
      -- Add skip message to notes (not fails) only during main case execution
      if is_case_executed then
        table.insert(case.exec.notes, H.cache.skip_message)
        H.cache.skip_message = nil
      end
      return true
    end

    -- Append traceback to error message and indent lines for pretty print
    local error_lines = { tostring(e), 'Traceback:', unpack(H.traceback()) }
    local error_msg = table.concat(error_lines, '\n'):gsub('\n', '\n  ')
    table.insert(case.exec.fails, error_msg)

    return false
  end

  local exec_step = function(f, state)
    update_state(state)

    H.cache.finally, H.cache.n_screenshots = {}, 0
    local ok_f, ok_err = xpcall(f, on_err)

    for _, fin in ipairs(H.cache.finally) do
      H.exec_callable(fin)
    end

    return ok_f or ok_err
  end

  local exec_hooks = function(name, source)
    local source_arr = case.hooks[name .. '_source']
    local state_prefix = "Executing '" .. name .. "' hook #"
    for i, h in ipairs(case.hooks[name]) do
      if source_arr[i] == source then exec_step(h, state_prefix .. i) end
    end
  end

  return function()
    if H.cache.should_stop_execution then return end

    case.exec = { fails = {}, notes = {} }
    MiniTest.current.case = case

    exec_hooks('pre', 'once')
    local exec_data = case.exec

    local ok_case
    for _ = 1, case.n_retry do
      -- Ensure that fails and notes are not accumulated during retries
      case.exec = vim.deepcopy(exec_data)

      -- Ensure that `skip()` affects only `pre_case` hooks and case
      H.cache.skip_message = nil

      -- Executing `*_case` hooks on every retry should ensure same case setup
      -- (like cleanly restarted child process)
      exec_hooks('pre', 'case')

      local case_f = function() case.test(unpack(case.args)) end
      if #case.exec.fails > 0 then
        case_f = function() table.insert(case.exec.notes, 'Skip case due to error(s) in hooks.') end
      end
      if H.cache.skip_message ~= nil then case_f = function() MiniTest.skip(H.cache.skip_message) end end

      is_case_executed = true
      ok_case = exec_step(case_f, 'Executing test')
      is_case_executed = false

      exec_hooks('post', 'case')

      if ok_case then break end
    end

    exec_hooks('post', 'once')

    update_state(H.case_final_state(case))

    if not ok_case and opts.stop_on_error then MiniTest.stop() end
  end
end

-- Work with test cases -------------------------------------------------------
--- Convert test set to array of test cases
---
---@return ... Tuple of aligned arrays: with test cases and hooks that should
---   be executed only once before corresponding item.
---@private
H.set_to_testcases = function(set, template, hooks_once)
  template = template or { args = {}, desc = {}, hooks = { pre = {}, post = {} }, data = {}, n_retry = 1 }
  hooks_once = hooks_once or { pre = {}, post = {} }

  local metatbl = getmetatable(set)
  local opts, key_order = metatbl.opts, metatbl.key_order
  local hooks, parametrize, data, n_retry = opts.hooks or {}, opts.parametrize or { {} }, opts.data or {}, opts.n_retry

  -- Convert to steps only callable or test set nodes
  -- Ensure that all elements of `set` are being considered (might not be the
  -- case if `table.insert` was used, for example)
  key_order = H.ensure_all_vals(key_order, vim.tbl_keys(set))
  local node_keys = vim.tbl_filter(function(key)
    local node = set[key]
    return vim.is_callable(node) or H.is_instance(node, 'testset')
  end, key_order)

  if #node_keys == 0 then return {}, {} end

  -- Ensure that newly added hooks are represented by new functions.
  -- This is needed to count them later only within current set. Example: use
  -- the same function in several `_once` hooks. In `H.inject_hooks_once` it
  -- will be injected only once overall whereas it should be injected only once
  -- within corresponding test set.
  hooks_once =
    H.extend_hooks(hooks_once, { pre = H.wrap_callable(hooks.pre_once), post = H.wrap_callable(hooks.post_once) })

  local testcase_arr, hooks_once_arr = {}, {}
  -- Process nodes in order they were added as `T[...] = x`
  for _, key in ipairs(node_keys) do
    local node = set[key]
    for _, args in ipairs(parametrize) do
      if type(args) ~= 'table' then H.error('`parametrize` should have only tables. Got ' .. vim.inspect(args)) end

      local cur_template = H.extend_template(template, {
        args = args,
        desc = type(key) == 'string' and key:gsub('\n', '\\n') or key,
        hooks = { pre = hooks.pre_case, post = hooks.post_case },
        data = data,
        n_retry = n_retry,
      })

      if vim.is_callable(node) then
        table.insert(testcase_arr, H.new_testcase(cur_template, node))
        table.insert(hooks_once_arr, hooks_once)
      elseif H.is_instance(node, 'testset') then
        local nest_testcase_arr, nest_hooks_once_arr = H.set_to_testcases(node, cur_template, hooks_once)
        vim.list_extend(testcase_arr, nest_testcase_arr)
        vim.list_extend(hooks_once_arr, nest_hooks_once_arr)
      end
    end
  end

  return testcase_arr, hooks_once_arr
end

H.ensure_all_vals = function(arr_subset, arr_all)
  local vals_registry = {}
  for _, v in ipairs(arr_subset) do
    vals_registry[v] = true
  end

  for _, v in ipairs(arr_all) do
    if not vals_registry[v] then
      table.insert(arr_subset, v)
      vals_registry[v] = true
    end
  end

  return arr_subset
end

H.inject_hooks_once = function(cases, hooks_once)
  -- NOTE: this heavily relies on the equivalence of "have same object id" and
  -- "are same hooks"
  local already_injected, n = {}, #cases

  -- Inject 'pre' hooks moving forwards
  for i = 1, n do
    local case, hooks = cases[i], hooks_once[i].pre
    case.hooks.pre_source = vim.tbl_map(function() return 'case' end, case.hooks.pre)
    local target_tbl_id = 1
    for j = 1, #hooks do
      local h = hooks[j]
      if not already_injected[h] then
        table.insert(case.hooks.pre, target_tbl_id, h)
        table.insert(case.hooks.pre_source, target_tbl_id, 'once')
        target_tbl_id, already_injected[h] = target_tbl_id + 1, true
      end
    end
  end

  -- Inject 'post' hooks moving backwards
  for i = n, 1, -1 do
    local case, hooks = cases[i], hooks_once[i].post
    case.hooks.post_source = vim.tbl_map(function() return 'case' end, case.hooks.post)
    local target_tbl_id = #case.hooks.post + 1
    for j = #hooks, 1, -1 do
      local h = hooks[j]
      if not already_injected[h] then
        table.insert(case.hooks.post, target_tbl_id, h)
        table.insert(case.hooks.post_source, target_tbl_id, 'once')
        already_injected[h] = true
      end
    end
  end

  return cases
end

H.new_testcase = function(template, test)
  template.test = test
  return template
end

H.extend_template = function(template, layer)
  local res = vim.deepcopy(template)

  vim.list_extend(res.args, layer.args)
  table.insert(res.desc, layer.desc)
  res.hooks = H.extend_hooks(res.hooks, layer.hooks, false)
  res.data = vim.tbl_deep_extend('force', res.data, layer.data)
  res.n_retry = layer.n_retry or res.n_retry or 1

  return res
end

H.extend_hooks = function(hooks, layer, do_deepcopy)
  local res = hooks
  if do_deepcopy == nil or do_deepcopy then res = vim.deepcopy(hooks) end

  -- Closer (in terms of nesting) hooks should be closer to test callable
  if vim.is_callable(layer.pre) then table.insert(res.pre, layer.pre) end
  if vim.is_callable(layer.post) then table.insert(res.post, 1, layer.post) end

  return res
end

H.case_to_stringid = function(case)
  local desc = table.concat(case.desc, ' | ')
  if #case.args == 0 then return desc end
  local args = vim.inspect(case.args, { newline = '', indent = '' })
  return ('%s + args %s'):format(desc, args)
end

H.case_final_state = function(case)
  local pass_fail = #case.exec.fails == 0 and 'Pass' or 'Fail'
  local with_notes = #case.exec.notes == 0 and '' or ' with notes'
  return string.format('%s%s', pass_fail, with_notes)
end

-- Dynamic overview reporter --------------------------------------------------
H.overview_reporter = {}

H.overview_reporter.compute_groups = function(cases, group_depth)
  local default_symbol = H.reporter_symbols[nil]
  return vim.tbl_map(function(c)
    local desc_trunc = vim.list_slice(c.desc, 1, group_depth)
    local name = table.concat(desc_trunc, ' | ')
    return { name = name, symbol = default_symbol }
  end, cases)
end

H.overview_reporter.start_lines = function(cases, groups)
  local unique_names = {}
  for _, g in ipairs(groups) do
    unique_names[g.name] = true
  end
  local n_groups = #vim.tbl_keys(unique_names)

  return {
    string.format('%s %s', H.add_style('Total number of cases:', 'emphasis'), #cases),
    string.format('%s %s', H.add_style('Total number of groups:', 'emphasis'), n_groups),
    '',
  }
end

H.overview_reporter.finish_lines = function(cases)
  -- Gather fails and notes (colored based on case fail/pass)
  local fails, notes = {}, {}
  local n_fails, n_notes = 0, 0
  for _, c in ipairs(cases) do
    local stringid = H.case_to_stringid(c)
    local exec = c.exec == nil and { fails = {}, notes = {} } or c.exec

    if #exec.fails > 0 then
      table.insert(fails, '')
      local fail_prefix = string.format('%s in %s: ', H.add_style('FAIL', 'fail'), stringid)
      vim.list_extend(fails, H.add_prefix(exec.fails, fail_prefix))
      n_fails = n_fails + #exec.fails
    end

    if #exec.notes > 0 then
      table.insert(notes, '')
      local note_color = #exec.fails > 0 and 'fail' or 'pass'
      local note_prefix = string.format('%s in %s: ', H.add_style('NOTE', note_color), stringid)
      vim.list_extend(notes, H.add_prefix(exec.notes, note_prefix))
      n_notes = n_notes + #exec.notes
    end
  end

  -- Show all fails first, then all notes
  local header = string.format('Fails (%s) and Notes (%s)', n_fails, n_notes)
  local res = { H.add_style(header, 'emphasis') }
  vim.list_extend(res, fails)
  vim.list_extend(res, notes)

  return vim.split(table.concat(res, '\n'), '\n')
end

-- Buffer reporter utilities --------------------------------------------------
H.buffer_reporter = { ns_id = vim.api.nvim_create_namespace('MiniTestBuffer'), n_buffer = 0 }

H.buffer_reporter.setup_buf_and_win = function(window_opts)
  local buf_id = vim.api.nvim_create_buf(true, true)
  H.set_buf_name(buf_id, 'buffer-reporter')

  local win_id
  if vim.is_callable(window_opts) then
    win_id = window_opts()
  elseif type(window_opts) == 'table' then
    -- Ensure proper title
    if type(window_opts.title) == 'string' then
      window_opts.title = H.fit_to_width(window_opts.title, window_opts.width)
    end
    win_id = vim.api.nvim_open_win(buf_id, true, window_opts)
  end
  win_id = win_id or vim.api.nvim_get_current_win()
  vim.api.nvim_win_set_buf(win_id, buf_id)

  H.buffer_reporter.set_options(buf_id, win_id)
  H.buffer_reporter.set_mappings(buf_id)

  return buf_id, win_id
end

H.buffer_reporter.default_window_opts = function()
  return {
    relative = 'editor',
    width = math.floor(0.618 * vim.o.columns),
    height = math.floor(0.618 * vim.o.lines),
    row = math.floor(0.191 * vim.o.lines),
    col = math.floor(0.191 * vim.o.columns),
    border = (vim.fn.exists('+winborder') == 0 or vim.o.winborder == '') and 'single' or nil,
    title = ' Test results ',
  }
end

H.buffer_reporter.set_options = function(buf_id, win_id)
  -- Set unique name
  local n_buffer = H.buffer_reporter.n_buffer + 1
  local suffix = n_buffer == 1 and '' or (' ' .. n_buffer)
  H.buffer_reporter.n_buffer = n_buffer

  vim.cmd('silent! set filetype=minitest')

  --stylua: ignore start
  -- Set options for "temporary" buffer
  local buf_options = {
    bufhidden = 'wipe', buflisted = false, buftype = 'nofile', modeline = false, swapfile = false,
  }
  for name, value in pairs(buf_options) do
    vim.bo[buf_id][name] = value
  end

  -- Set options for "clean" window
  local win_options = {
    colorcolumn = '', fillchars = 'eob: ',    foldcolumn = '0', foldlevel = 999,
    number = false,   relativenumber = false, spell = false,    signcolumn = 'no',
    wrap = true,
  }
  for name, value in pairs(win_options) do
    vim.wo[win_id][name] = value
  end
  --stylua: ignore end
end

H.buffer_reporter.set_mappings = function(buf_id)
  local rhs = [[lua if MiniTest.is_executing() then MiniTest.stop() else vim.cmd('close') end]]
  vim.keymap.set('n', '', rhs, { buffer = buf_id, desc = 'Stop execution or close window' })
  vim.keymap.set('n', 'q', rhs, { buffer = buf_id, desc = 'Stop execution or close window' })
end

H.buffer_reporter.set_lines = function(buf_id, lines, start, finish)
  local ns_id = H.buffer_reporter.ns_id

  local n_lines = vim.api.nvim_buf_line_count(buf_id)
  start = (start < 0) and (n_lines + 1 + start) or start
  finish = (finish < 0) and (n_lines + 1 + finish) or finish

  -- Remove ANSI codes while tracking appropriate highlight data
  local new_lines, hl_ranges = {}, {}
  for i, l in ipairs(lines) do
    local n_removed = 0
    local new_l = l:gsub('\n', '\\n'):gsub('()(\27%[.-m)(.-)\27%[0m', function(...)
      local dots = { ... }
      local left = dots[1] - n_removed
      table.insert(
        hl_ranges,
        { hl = H.hl_groups[dots[2]], line = start + i - 1, left = left - 1, right = left + dots[3]:len() - 1 }
      )

      -- Here `4` is `string.len('\27[0m')`
      n_removed = n_removed + dots[2]:len() + 4
      return dots[3]
    end)
    table.insert(new_lines, new_l)
  end

  -- Clear highlighting on updated lines. Crucial because otherwise it will
  -- lead to A LOT of memory consumption.
  vim.api.nvim_buf_clear_namespace(buf_id, H.buffer_reporter.ns_id, start, finish)

  -- Set lines
  vim.api.nvim_buf_set_lines(buf_id, start, finish, true, new_lines)

  -- Add highlight
  for _, hl_data in ipairs(hl_ranges) do
    H.highlight_range(buf_id, ns_id, hl_data.hl, { hl_data.line, hl_data.left }, { hl_data.line, hl_data.right })
  end
end

H.buffer_reporter.update_step_lines = function(case_num, cases, groups)
  local cur_case = cases[case_num]
  local cur_group = groups[case_num].name

  -- Don't show anything before empty group name (when `group_depth` is 0)
  local cur_group_suffix = cur_group == '' and '' or ': '
  local cur_group_symbols = vim.tbl_map(
    function(g) return g.symbol end,
    vim.tbl_filter(function(g) return g.name == cur_group end, groups)
  )

  return {
    -- Group overview
    string.format('%s%s%s', cur_group, cur_group_suffix, table.concat(cur_group_symbols)),
    '',
    H.add_style('Current case state', 'emphasis'),
    string.format('%s: %s', H.case_to_stringid(cur_case), cur_case.exec.state),
  }
end

H.buffer_reporter.update_step_n_replace = function(latest_group_name, cur_group_name)
  -- By default rewrite latest group symbol overview
  local res = 4

  if latest_group_name == nil then
    -- Nothing to rewrite on first ever call
    res = 0
  elseif latest_group_name ~= cur_group_name then
    -- Write just under latest group symbol overview
    res = 3
  end

  return res
end

-- Predicates -----------------------------------------------------------------
H.is_instance = function(x, class)
  local metatbl = getmetatable(x)
  return type(metatbl) == 'table' and metatbl.class == class
end

H.has_fails = function(cases)
  for _, c in ipairs(cases) do
    local n_fails = c.exec == nil and 0 or #c.exec.fails
    if n_fails > 0 then return true end
  end
  return false
end

-- Expectation utilities ------------------------------------------------------
H.normalize_reason = function(reason, fallback, ...)
  if vim.is_callable(reason) then reason = reason(...) end
  if type(reason) ~= 'string' then reason = fallback end
  return reason
end

H.error_with_emphasis = function(msg, context)
  local lines = { '', H.add_style(msg, 'emphasis'), context }
  error(table.concat(lines, '\n'), 0)
end

H.traceback = function()
  local level, res = 1, {}
  local info = debug.getinfo(level, 'Snl')
  local this_short_src = info.short_src
  while info ~= nil do
    local is_from_file = info.source:sub(1, 1) == '@'
    local is_from_this_file = info.short_src == this_short_src
    if is_from_file and not is_from_this_file then
      local line = string.format([[  %s:%s]], info.short_src, info.currentline)
      table.insert(res, line)
    end
    level = level + 1
    info = debug.getinfo(level, 'Snl')
  end

  return res
end

H.compute_no_equality_cause = function(left, right)
  if type(left) ~= type(right) then return 'different types' end

  if type(left) == 'string' then
    if vim.fn.strchars(left) ~= vim.fn.strchars(right) then return 'different string length' end
    for i = 1, vim.fn.strchars(left) do
      local lchar, rchar = vim.fn.strcharpart(left, i - 1, 1), vim.fn.strcharpart(right, i - 1, 1)
      if lchar ~= rchar then
        return string.format('different character at position %s', i)
          .. string.format(', left = %s, right = %s', vim.inspect(lchar), vim.inspect(rchar))
      end
    end
  end

  if type(left) ~= 'table' then return 'different values' end

  -- Find key branch with different values
  local traverse
  traverse = function(branch, diff, a, b)
    if not (type(a) == 'table' and type(b) == 'table') then return end
    local keys = vim.tbl_keys(a)
    table.sort(keys, function(x, y) return tostring(x) < tostring(y) end)
    for _, k in ipairs(keys) do
      if not vim.deep_equal(a[k], b[k]) then
        table.insert(branch, k)
        diff.left, diff.right = a[k], b[k]
        return traverse(branch, diff, a[k], b[k])
      end
    end
  end

  -- - Traverse with both table orders to find the longest possible branch.
  --   This also covers the "present in one but not the other" cases.
  local left_branch, left_diff = {}, {}
  traverse(left_branch, left_diff, left, right)
  local right_branch, right_diff = {}, {}
  traverse(right_branch, right_diff, right, left)

  local branch, ldiff, rdiff = left_branch, left_diff.left, left_diff.right
  if #left_branch < #right_branch then
    branch, ldiff, rdiff = right_branch, right_diff.right, right_diff.left
  end
  ldiff = vim.inspect(ldiff, { newline = ' ', indent = '' })
  rdiff = vim.inspect(rdiff, { newline = ' ', indent = '' })
  local key_branch = table.concat(vim.tbl_map(vim.inspect, branch), '->')
  return string.format('different values at key %s%s', #branch > 1 and 'branch ' or '', key_branch)
    .. string.format(', left = %s, right = %s', ldiff, rdiff)
end

-- Screenshots ----------------------------------------------------------------
H.screenshot_new = function(t)
  local process_screen = function(arr_2d)
    local n_lines, n_cols = #arr_2d, #arr_2d[1]

    -- Prepend lines with line number of the form `01|`
    local n_digits = math.floor(math.log10(n_lines)) + 1
    local format = string.format('%%0%dd|%%s', n_digits)
    local lines = {}
    for i = 1, n_lines do
      table.insert(lines, string.format(format, i, table.concat(arr_2d[i])))
    end

    -- Make ruler
    local prefix = string.rep('-', n_digits) .. '|'
    local ruler = prefix .. ('---------|'):rep(math.ceil(0.1 * n_cols)):sub(1, n_cols)

    return string.format('%s\n%s', ruler, table.concat(lines, '\n'))
  end

  return setmetatable(t, {
    __tostring = function(x) return string.format('%s\n\n%s', process_screen(x.text), process_screen(x.attr)) end,
  })
end

H.screenshot_encode_attr = function(attr)
  local attr_codes, res = {}, {}
  -- Use 48 so that codes start from `'0'`
  local cur_code_id = 48
  for _, l in ipairs(attr) do
    local res_line = {}
    for _, s in ipairs(l) do
      -- Assign character codes to numerical attributes in order of their
      -- appearance on the screen. This leads to be a more reliable way of
      -- comparing two different screenshots (at cost of bigger effect when
      -- screenshot changes slightly).
      if not attr_codes[s] then
        attr_codes[s] = string.char(cur_code_id)
        -- Cycle through 33...126
        cur_code_id = math.fmod(cur_code_id + 1 - 33, 94) + 33
      end
      table.insert(res_line, attr_codes[s])
    end
    table.insert(res, res_line)
  end

  return res
end

H.screenshot_compare_part = function(part, ref, obs, opts)
  local ignore_part = opts['ignore_' .. part]
  if ignore_part == true then return true, '' end

  local compare = function(x, y, desc)
    if x == y then return true, '' end
    return false, ('Cause: different %s, reference = %s, observed = %s'):format(desc, vim.inspect(x), vim.inspect(y))
  end

  local ok, cause
  ok, cause = compare(#ref[part], #obs[part], 'number of `' .. part .. '` lines')
  if not ok then return ok, cause end

  local lines_to_check = {}
  for i = 1, #ref[part] do
    local is_ignore_part = type(ignore_part) == 'table' and vim.tbl_contains(ignore_part, i)
    if not is_ignore_part then table.insert(lines_to_check, i) end
  end

  for _, i in ipairs(lines_to_check) do
    ok, cause = compare(#ref[part][i], #obs[part][i], 'number of columns in `' .. part .. '` line ' .. i)
    if not ok then return ok, cause end

    for j = 1, #ref[part][i] do
      ok, cause = compare(ref[part][i][j], obs[part][i][j], '`' .. part .. '` cell at line ' .. i .. ' column ' .. j)
      if not ok then return ok, cause end
    end
  end

  return true, ''
end

H.screenshot_write = function(screenshot, path) vim.fn.writefile(vim.split(tostring(screenshot), '\n'), path) end

H.screenshot_read = function(path)
  -- General structure of screenshot with `n` lines:
  -- 1: ruler-separator
  -- 2, n+1: `prefix`|`text`
  -- n+2: empty line
  -- n+3: ruler-separator
  -- n+4, 2n+3: `prefix`|`attr`
  local lines = vim.fn.readfile(path)
  local n = 0.5 * (#lines - 3)
  local text_lines, attr_lines = vim.list_slice(lines, 2, n + 1), vim.list_slice(lines, n + 4, 2 * n + 3)

  local f = function(x) return H.string_to_screenchars(x:gsub('^%d+|', '')) end
  return H.screenshot_new({ text = vim.tbl_map(f, text_lines), attr = vim.tbl_map(f, attr_lines) })
end

-- Utilities ------------------------------------------------------------------
H.error = function(msg) error('(mini.test) ' .. msg, 0) end

H.check_type = function(name, val, ref, allow_nil)
  if type(val) == ref or (ref == 'callable' and vim.is_callable(val)) or (allow_nil and val == nil) then return end
  H.error(string.format('`%s` should be %s, not %s', name, ref, type(val)))
end

H.set_buf_name = function(buf_id, name) vim.api.nvim_buf_set_name(buf_id, 'minitest://' .. buf_id .. '/' .. name) end

H.echo = function(msg, is_important)
  if H.get_config().silent then return end

  -- Construct message chunks
  msg = type(msg) == 'string' and { { msg } } or msg
  table.insert(msg, 1, { '(mini.test) ', 'WarningMsg' })

  -- Echo. Force redraw to ensure that it is effective (`:h echo-redraw`)
  vim.cmd([[echo '' | redraw]])
  vim.api.nvim_echo(msg, is_important, {})
end

H.message = function(msg) H.echo(msg, true) end

H.wrap_callable = function(f)
  if not vim.is_callable(f) then return end
  return function(...) return f(...) end
end

H.exec_callable = function(f, ...)
  if not vim.is_callable(f) then return end
  return f(...)
end

H.add_prefix = function(tbl, prefix)
  return vim.tbl_map(function(x)
    local p = prefix
    -- Do not create trailing whitespace
    if x:sub(1, 1) == '\n' then p = p:gsub('%s*$', '') end
    return ('%s%s'):format(p, x)
  end, tbl)
end

H.add_style = function(x, ansi_code) return string.format('%s%s%s', H.ansi_codes[ansi_code], x, H.ansi_codes.reset) end

H.fit_to_width = function(text, width)
  local t_width = vim.fn.strchars(text)
  return t_width <= width and text or ('…' .. vim.fn.strcharpart(text, t_width - width + 1, width - 1))
end

H.string_to_screenchars = function(s)
  -- Can't use `vim.split(s, '')` because of multibyte characters
  local res = {}
  for i = 1, vim.fn.strchars(s) do
    local ch = vim.fn.strcharpart(s, i - 1, 1)
    table.insert(res, ch)
    -- Not single-width characters are read as a single char, but result into
    -- `{ ch, '', ... }` when computing observed screenshot (as this is how
    -- `vim.fn.screenstring()` works)
    for _ = 1, vim.fn.strdisplaywidth(ch) - 1 do
      table.insert(res, '')
    end
  end
  return res
end

-- TODO: Remove after compatibility with Neovim=0.9 is dropped
H.tbl_flatten = vim.fn.has('nvim-0.10') == 1 and function(x) return vim.iter(x):flatten(math.huge):totable() end
  or vim.tbl_flatten

-- TODO: Remove after compatibility with Neovim=0.10 is dropped
H.highlight_range = function(...) vim.hl.range(...) end
if vim.fn.has('nvim-0.11') == 0 then H.highlight_range = function(...) vim.highlight.range(...) end end

return MiniTest