feat: option to skip merge commits format check

Author: zlodes

README.md

@@ -152,6 +152,7 @@ options:
   --no-color       Disable color in output.
   --force-scope    Force commit to have scope defined.
   --scopes SCOPES  Optional list of scopes to support. Scopes should be separated by commas with no spaces (e.g. api,client)
+  --skip-merges    Do not check format for merge commits.
   --strict         Force commit to strictly follow Conventional Commits formatting. Disallows fixup! style commits.
   --verbose        Print more verbose error output.
 ```

conventional_pre_commit/format.py

@@ -159,3 +159,13 @@ def has_autosquash_prefix(input):
     regex = re.compile(pattern, re.DOTALL)
 
     return bool(regex.match(input))
+
+def is_merge_commit(input):
+    """
+    Returns True if input starts with 'Merge branch '.
+
+    It doesn't check whether the rest of the input matches Conventional Commits
+    formatting.
+    """
+
+    return input.startswith("Merge branch ")

conventional_pre_commit/hook.py

@@ -23,6 +23,13 @@ def main(argv=[]):
         default=None,
         help="Optional list of scopes to support. Scopes should be separated by commas with no spaces (e.g. api,client)",
     )
+    parser.add_argument(
+        "--skip-merges",
+        action="store_true",
+        default=False,
+        dest="skip_merges",
+        help="Do not check format for merge commits.",
+    )
     parser.add_argument(
         "--strict",
         action="store_true",
@@ -55,6 +62,10 @@ def main(argv=[]):
     else:
         scopes = args.scopes
 
+    if args.skip_merges:
+        if format.is_merge_commit(commit_msg):
+            return RESULT_SUCCESS
+
     if not args.strict:
         if format.has_autosquash_prefix(commit_msg):
             return RESULT_SUCCESS

tests/conftest.py

@@ -44,6 +44,11 @@ def fixup_commit_path():
     return get_message_path("fixup_commit")
 
 
+@pytest.fixture
+def merge_commit_path():
+    return get_message_path("merge_commit")
+
+
 @pytest.fixture
 def conventional_commit_bad_multi_line_path():
     return get_message_path("conventional_commit_bad_multi_line")

tests/messages/merge_commit

@@ -0,0 +1 @@
+Merge branch '2.x.x' into '1.x.x'

tests/test_format.py

@@ -124,6 +124,8 @@ def test_r_autosquash_prefixes():
     for prefix in format.AUTOSQUASH_PREFIXES:
         assert regex.match(prefix)
 
+def test_merge_commit():
+    assert format.is_merge_commit("Merge branch '2.x.x' into '1.x.x'")
 
 def test_conventional_types__default():
     result = format.conventional_types()

tests/test_hook.py

@@ -84,6 +84,18 @@ def test_main_fail__fixup_commit(fixup_commit_path):
     assert result == RESULT_FAIL
 
 
+def test_main_fail__merge_commit(merge_commit_path):
+    result = main([merge_commit_path])
+
+    assert result == RESULT_FAIL
+
+
+def test_main_success__merge_commit(merge_commit_path):
+    result = main(["--skip-merges", merge_commit_path])
+
+    assert result == RESULT_SUCCESS
+
+
 def test_main_success__conventional_commit_multi_line(conventional_commit_multi_line_path):
     result = main([conventional_commit_multi_line_path])