From 65572c719a323ad92603fc82801827841ff81a7d Mon Sep 17 00:00:00 2001
From: dundargoc <33953936+dundargoc@users.noreply.github.com>
Date: Sun, 19 Sep 2021 18:27:08 +0200
Subject: [PATCH] build(lint): commit linter #15620

---
 Makefile               |  11 ++-
 scripts/lintcommit.lua | 147 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 156 insertions(+), 2 deletions(-)
 create mode 100644 scripts/lintcommit.lua

diff --git a/Makefile b/Makefile
index 39f42739ff..2cbedaf0b1 100644
--- a/Makefile
+++ b/Makefile
@@ -163,6 +163,13 @@ _opt_pylint:
 	@command -v flake8 && { $(MAKE) pylint; exit $$?; } \
 		|| echo "SKIP: pylint (flake8 not found)"
 
+commitlint:
+	$(realpath build/bin/nvim) --clean -es +"luafile scripts/lintcommit.lua"
+
+_opt_commitlint:
+	@test -x build/bin/nvim && { $(MAKE) commitlint; exit $$?; } \
+		|| echo "SKIP: commitlint (build/bin/nvim not found)"
+
 unittest: | nvim
 	+$(BUILD_CMD) -C build unittest
 
@@ -205,7 +212,7 @@ appimage:
 appimage-%:
 	bash scripts/genappimage.sh $*
 
-lint: check-single-includes clint lualint _opt_pylint _opt_shlint
+lint: check-single-includes clint lualint _opt_pylint _opt_shlint _opt_commitlint
 
 # Generic pattern rules, allowing for `make build/bin/nvim` etc.
 # Does not work with "Unix Makefiles".
@@ -217,4 +224,4 @@ $(DEPS_BUILD_DIR)/%: phony_force
 	$(BUILD_CMD) -C $(DEPS_BUILD_DIR) $(patsubst $(DEPS_BUILD_DIR)/%,%,$@)
 endif
 
-.PHONY: test lualint pylint shlint functionaltest unittest lint clint clean distclean nvim libnvim cmake deps install appimage checkprefix
+.PHONY: test lualint pylint shlint functionaltest unittest lint clint clean distclean nvim libnvim cmake deps install appimage checkprefix commitlint
diff --git a/scripts/lintcommit.lua b/scripts/lintcommit.lua
new file mode 100644
index 0000000000..64daee7249
--- /dev/null
+++ b/scripts/lintcommit.lua
@@ -0,0 +1,147 @@
+local function commit_message_is_ok(commit_message)
+  local commit_split = vim.split(commit_message, ":")
+
+  -- Return true if the type is vim-patch since most of the normal rules don't
+  -- apply.
+  if commit_split[1] == "vim-patch" then
+    return true
+  end
+
+  -- Check that message isn't too long.
+  if commit_message:len() > 80 then
+    vim.cmd([[verbose echo "Commit message is too long, a maximum of 80 characters is allowed. Commit message:"]])
+    return false
+  end
+
+  -- Return false if no colons are detected.
+  if vim.tbl_count(commit_split) < 2 then
+    vim.cmd([[verbose echo "Commit message does not include colons. Commit message:"]])
+    return false
+  end
+
+  local before_colon = commit_split[1]
+  local after_colon = commit_split[2]
+
+  -- Check if commit introduces a breaking change.
+  if vim.endswith(before_colon, "!") then
+    before_colon = before_colon:sub(1, -2)
+  end
+
+  -- Check if type is correct
+  local type = vim.split(before_colon, "%(")[1]
+  local allowed_types = {"build", "ci", "docs", "feat", "fix", "perf", "refactor", "revert", "test", "chore"}
+  if not vim.tbl_contains(allowed_types, type) then
+    vim.cmd([[verbose echo "Commit type is not recognized. Allowed types are: build, ci, docs, feat, fix, perf, refactor, revert, test, chore. Commit message:"]])
+    return false
+  end
+
+  -- Check if scope is empty
+  if before_colon:match("%(") then
+    local scope = vim.trim(before_colon:match("%((.*)%)"))
+    if scope == '' then
+      vim.cmd([[verbose echo "Scope can't be empty. Commit message:"]])
+      return false
+    end
+  end
+
+  -- Check that description doesn't end with a period
+  if vim.endswith(after_colon, ".") then
+      vim.cmd([[verbose echo "Description ends with a period (\".\"). Commit message:"]])
+    return false
+  end
+
+  -- Check that description has exactly one whitespace after colon, followed by
+  -- a lowercase letter and then any number of letters.
+  if not string.match(after_colon, '^ %l%a*') then
+      vim.cmd([[verbose echo "There should be one whitespace after the colon and the first letter should lowercase. Commit message:"]])
+    return false
+  end
+
+  return true
+end
+
+local function main()
+  local current_branch = vim.trim(vim.fn.system({'git', 'branch', '--show-current'}))
+  local ancestor_commit = vim.trim(vim.fn.system({'git', 'merge-base', 'origin/master', current_branch}))
+  local commits_str = vim.trim(vim.fn.system({'git', 'rev-list', ancestor_commit .. ".." .. current_branch}))
+
+  local commits = {}
+  for substring in commits_str:gmatch("%S+") do
+     table.insert(commits, substring)
+  end
+
+  for _, commit_hash in ipairs(commits) do
+    local message = vim.trim(vim.fn.system({'git', 'show', '-s', '--format=%s' , commit_hash}))
+    if vim.v.shell_error ~= 0 then
+      vim.cmd('verbose echo "Invalid commit-id: ' .. commit_hash .. '"')
+    elseif not commit_message_is_ok(message) then
+      vim.cmd("verbose echo '" .. message:gsub("'","''") .. "'")
+      vim.cmd('verbose echo ""')
+      vim.cmd("cquit 1")
+    end
+  end
+end
+
+local function _test()
+  local good_messages = {
+    "ci: normal message",
+    "build: normal message",
+    "docs: normal message",
+    "feat: normal message",
+    "fix: normal message",
+    "perf: normal message",
+    "refactor: normal message",
+    "revert: normal message",
+    "test: normal message",
+    "chore: normal message",
+    "ci(window): message with scope",
+    "ci!: message with breaking change",
+    "ci(tui)!: message with scope and breaking change",
+    "vim-patch:8.2.3374: Pyret files are not recognized (#15642)",
+    "vim-patch:8.1.1195,8.2.{3417,3419}",
+  }
+
+  local bad_messages = {
+    ":no type before colon 1",
+    " :no type before colon 2",
+    "  :no type before colon 3",
+    "ci(empty description):",
+    "ci(whitespace as description): ",
+    "docs(multiple whitespaces as description):   ",
+    "ci no colon after type",
+    "test:  extra space after colon",
+    "ci:	tab after colon",
+    "ci:no space after colon",
+    "ci :extra space before colon",
+    "refactor(): empty scope",
+    "ci( ): whitespace as scope",
+    "chore: period at end of sentence.",
+    "ci: Starting sentence capitalized",
+    "unknown: using unknown type",
+    "chore: you're saying this commit message just goes on and on and on and on and on and on for way too long?",
+  }
+
+  print("Messages expected to pass:")
+
+  for _, message in ipairs(good_messages) do
+    if commit_message_is_ok(message) then
+      print("[ PASSED ] :", message)
+    else
+      print("[ FAIL ]   :", message)
+    end
+  end
+
+  print("Messages expected to fail:")
+
+  for _, message in ipairs(bad_messages) do
+    if commit_message_is_ok(message) then
+      print("[ PASSED ] :", message)
+    else
+      print("[ FAIL ]   :", message)
+    end
+  end
+end
+
+-- _test()
+
+main()