-- Validate commit message. Designed to be run as pre-commit hook and in CI.

--

-- Each Neovim's argument for when it is opened is assumed to be a path to

-- a file containing commit message to validate

-- Example usage:

-- ```

-- nvim --headless --noplugin -u scripts/lintcommit.lua -- .git/COMMIT_EDITMSG

-- ```

-- Validator functions

local allowed_commit_types = { 'ci', 'docs', 'feat', 'fix', 'refactor', 'style', 'test' }

local allowed_scopes = { 'ALL' }

for _, module in ipairs(vim.fn.readdir('lua/mini')) do

if module ~= 'init.lua' then table.insert(allowed_scopes, module:match('^(.+)%.lua$')) end

end

local validate_subject = function(line)

-- Possibly allow starting with 'fixup' to disable commit linting

if vim.startswith(line, 'fixup') then

local fail_on_fixup = vim.loop.os_getenv('LINTCOMMIT_FAIL_ON_FIXUP') ~= nil

local msg = fail_on_fixup and 'No "fixup" commits are allowed.' or ''

return not fail_on_fixup, msg

end

-- Should match overall conventional commit spec

local commit_type, scope, desc = string.match(line, '^([^(]+)(%b())!?: (.+)$')

if commit_type == nil then

commit_type, desc = string.match(line, '^([^!:]+)!?: (.+)$')

end

if commit_type == nil or desc == nil then

return false,

'First line does not match conventional commit specification of `<type>[optional scope][!]: <description>`: '

.. vim.inspect(line)

end

-- Commit type should be present and be from one of allowed

if not vim.tbl_contains(allowed_commit_types, commit_type) then

local one_of = table.concat(vim.tbl_map(vim.inspect, allowed_commit_types), ', ')

return false, 'Commit type ' .. vim.inspect(commit_type) .. ' is not allowed. Use one of ' .. one_of .. '.'

end

-- Scope, if present, should be from one of allowed

if scope ~= nil then

scope = scope:sub(2, -2)

if not vim.tbl_contains(allowed_scopes, scope) then

local one_of = table.concat(vim.tbl_map(vim.inspect, allowed_scopes), ', ')

return false, 'Scope ' .. vim.inspect(scope) .. ' is not allowed. Use one of ' .. one_of .. '.'

end

end

-- Description should be present and properly formatted

if string.find(desc, '^%w') == nil then

return false, 'Description should start with alphanumeric character: ' .. vim.inspect(desc)

end

if string.find(desc, '^%u%l') ~= nil then

return false, 'Description should not start with capitalized word: ' .. vim.inspect(desc)

end

if string.find(desc, '[.,?!;]$') ~= nil then

return false, 'Description should not end with any of `.,?!;`: ' .. vim.inspect(desc)

end

-- Subject should not be too long

if vim.fn.strdisplaywidth(line) > 72 then

return false, 'First line is longer than 72 characters: ' .. vim.inspect(desc)

end

return true, nil

end

local validate_body = function(parts)

if #parts == 1 then return true, nil end

if parts[2] ~= '' then return false, 'Second line should be empty' end

if parts[3] == nil then return false, 'If first line is not enough, body should be present' end

if string.find(parts[3], '^%S') == nil then return false, 'First body line should not start with whitespace.' end

for i = 3, #parts do

if vim.fn.strdisplaywidth(parts[i]) > 80 then

return false, 'Body line is longer than 80 characters: ' .. vim.inspect(parts[i])

end

end

if string.find(parts[#parts], '^%s*$') ~= nil then return false, 'Body should not end with blank line.' end

return true, nil

end

local validate_bad_wording = function(msg)

local has_fix = msg:find('[Ff]ix #') or msg:find('[Ff]ixes #') or msg:find('[Ff]ixed #')

local has_bad_close = msg:find('[Cc]lose[sd]? #') ~= nil

local has_bad_resolve = msg:find('[Rr]esolve[sd] #') ~= nil

if has_fix or has_bad_close or has_bad_resolve then

return false,

'Use "Resolve #" GitHub keyword to resolve issue/PR '

.. '(not "Fix(/es/ed)", not "Close(/s/d)", not "Resolve(s/d)").'

end

return true, nil

end

local validate_commit_msg = function(lines)

-- Ignore Git comments

lines = vim.tbl_filter(function(l) return l:find('^%s*#') == nil end, lines)

local is_valid, err_msg

-- Allow all lines to be empty to abort commiting

local all_empty = true

for _, l in ipairs(lines) do

if l ~= '' then all_empty = false end

end

if all_empty then return true, nil end

-- Validate subject (first line)

is_valid, err_msg = validate_subject(lines[1])

if not is_valid then return is_valid, err_msg end

-- Validate body

is_valid, err_msg = validate_body(lines)

if not is_valid then return is_valid, err_msg end

-- No validation for footer

-- Should not contain bad wording

for _, l in ipairs(lines) do

is_valid, err_msg = validate_bad_wording(l)

if not is_valid then return is_valid, err_msg end

end

return true, nil

end

local validate_commit_msg_from_file = function(path)

local ok, lines = pcall(vim.fn.readfile, path)

if not ok then return false, 'Could not read file ' .. path end

return validate_commit_msg(lines)

end

-- Actual validation

local exit_code = 0

for i = 0, vim.fn.argc(-1) - 1 do

local path = vim.fn.argv(i, -1)

io.write('Commit message of ' .. vim.fn.fnamemodify(path, ':t') .. ':\n')

local is_valid, err_msg = validate_commit_msg_from_file(path)

io.write((is_valid and 'OK' or err_msg) .. '\n\n')

if not is_valid then exit_code = 1 end

end

os.exit(exit_code)

-- Tests to be run interactively: `_G.test_cases_failed` should be empty.

-- NOTE: Comment out previous `os.exit()` call

local test_cases = {

-- Subject

['fixup'] = true,

['fixup: commit message'] = true,

['fixup! commit message'] = true,

['ci: normal message'] = true,

['docs: normal message'] = true,

['feat: normal message'] = true,

['fix: normal message'] = true,

['refactor: normal message'] = true,

['style: normal message'] = true,

['test: normal message'] = true,

['feat(ai): message with scope'] = true,

['feat!: message with breaking change'] = true,

['feat(ai)!: message with scope and breaking change'] = true,

['style(ALL): style all modules'] = true,

['unknown: unknown type'] = false,

['feat(unknown): unknown scope'] = false,

['refactor(): empty scope'] = false,

['ci( ): whitespace as scope'] = false,

['ci no colon after type'] = false,

[': no type before colon 1'] = false,

[' : no type before colon 2'] = false,

[' : no type before colon 3'] = false,

['ci:'] = false,

['ci: '] = false,

['ci: '] = false,

['feat: message with : in it'] = true,

['feat(ai): message with : in it'] = true,

['test: extra space after colon'] = false,

['ci: tab after colon'] = false,

['ci:no space after colon'] = false,

['ci : extra space before colon'] = false,

['ci: bad punctuation at end of sentence.'] = false,

['ci: bad punctuation at end of sentence,'] = false,

['ci: bad punctuation at end of sentence?'] = false,

['ci: bad punctuation at end of sentence!'] = false,

['ci: bad punctuation at end of sentence;'] = false,

['ci: good punctuation at end of sentence:'] = true,

['ci: good punctuation at end of sentence"'] = true,

["ci: good punctuation at end of sentence'"] = true,

['ci: good punctuation at end of sentence)'] = true,

['ci: good punctuation at end of sentence]'] = true,

['ci: Capitalized first word'] = false,

['ci: UPPER_CASE First Word'] = true,

['ci: very very very very very very very very very very very looong subject'] = false,

-- Body

['ci: desc\n\nBody'] = true,

['ci: desc\n\nBody\n\nwith\n \nempty and blank lines'] = true,

['ci: desc\nSecond line is not empty'] = false,

['ci: desc\n\n First body line starts with whitespace'] = false,

['ci: desc\n\nBody\nwith\nVery very very very very very very very very very very very very looong body line'] = false,

['ci: only two lines\n\n'] = false,

['ci: desc\n\nLast line is empty\n\n'] = false,

['ci: desc\n\nLast line is blank\n '] = false,

-- Footer

-- No validation for footer

-- Bad wordings

['ci: this has Fixed #1'] = false,

['ci: this has fixed #1'] = false,

['ci: this Fixes #1'] = false,

['ci: this fixes #1'] = false,

['ci: this will Fix #1'] = false,

['ci: this will fix #1'] = false,

['ci: this has Closed #1'] = false,

['ci: this has closed #1'] = false,

['ci: this Closes #1'] = false,

['ci: this closes #1'] = false,

['ci: this will Close #1'] = false,

['ci: this will close #1'] = false,

['ci: this has Resolved #1'] = false,

['ci: this has resolved #1'] = false,

['ci: this Resolves #1'] = false,

['ci: this resolves #1'] = false,

['ci: desc\n\nthis has Fixed #1'] = false,

['ci: desc\n\nthis has fixed #1'] = false,

['ci: desc\n\nthis Fixes #1'] = false,

['ci: desc\n\nthis fixes #1'] = false,

['ci: desc\n\nthis will Fix #1'] = false,

['ci: desc\n\nthis will fix #1'] = false,

['ci: desc\n\nthis has Closed #1'] = false,

['ci: desc\n\nthis has closed #1'] = false,

['ci: desc\n\nthis Closes #1'] = false,

['ci: desc\n\nthis closes #1'] = false,

['ci: desc\n\nthis will Close #1'] = false,

['ci: desc\n\nthis will close #1'] = false,

['ci: desc\n\nthis has Resolved #1'] = false,

['ci: desc\n\nthis has resolved #1'] = false,

['ci: desc\n\nthis Resolves #1'] = false,

['ci: desc\n\nthis resolves #1'] = false,

-- Ignore comments

['# Comment\nci: desc'] = true,

[' # Comment\nci: desc'] = true,

['ci: desc\n# Comment\n\nBody'] = true,

-- Allow all empty lines

[''] = true,

['\n'] = true,

['\n# Comment'] = true,

}

_G.test_cases_failed = {}

vim.loop.os_unsetenv('LINTCOMMIT_FAIL_ON_FIXUP')

for message, expected in pairs(test_cases) do

local lines = vim.split(message, '\n')

local is_valid = validate_commit_msg(lines)

if is_valid ~= expected then

table.insert(_G.test_cases_failed, { msg = message, expected = expected, actual = is_valid })

end

end

local fixup_test_cases = {

['fixup'] = false,

['fixup: should fail'] = false,

['fixup! should fail'] = false,

-- Should only matter in subject

['ci: desc\n\nfixup'] = true,

}

vim.loop.os_setenv('LINTCOMMIT_FAIL_ON_FIXUP', 'true')

for message, expected in pairs(fixup_test_cases) do

local lines = vim.split(message, '\n')

local is_valid = validate_commit_msg(lines)

if is_valid ~= expected then

table.insert(_G.test_cases_failed, { msg = message, expected = expected, actual = is_valid })

end

end