Merging upstream version 0.17.0.

Signed-off-by: Daniel Baumann <daniel@debian.org>

gitlint-core/gitlint/contrib/rules/conventional_commit.py

@@ -0,0 +1,37 @@
+import re
+
+from gitlint.options import ListOption
+from gitlint.rules import CommitMessageTitle, LineRule, RuleViolation
+
+RULE_REGEX = re.compile(r"([^(]+?)(\([^)]+?\))?!?: .+")
+
+
+class ConventionalCommit(LineRule):
+    """ This rule enforces the spec at https://www.conventionalcommits.org/. """
+
+    name = "contrib-title-conventional-commits"
+    id = "CT1"
+    target = CommitMessageTitle
+
+    options_spec = [
+        ListOption(
+            "types",
+            ["fix", "feat", "chore", "docs", "style", "refactor", "perf", "test", "revert", "ci", "build"],
+            "Comma separated list of allowed commit types.",
+        )
+    ]
+
+    def validate(self, line, _commit):
+        violations = []
+        match = RULE_REGEX.match(line)
+
+        if not match:
+            msg = "Title does not follow ConventionalCommits.org format 'type(optional-scope): description'"
+            violations.append(RuleViolation(self.id, msg, line))
+        else:
+            line_commit_type = match.group(1)
+            if line_commit_type not in self.options["types"].value:
+                opt_str = ', '.join(self.options['types'].value)
+                violations.append(RuleViolation(self.id, f"Title does not start with one of {opt_str}", line))
+
+        return violations