feat(subject): make uppercase description check configurable

README.md

@@ -95,6 +95,41 @@ By default there is no minimum description length. Enforce one with
 commit-guard --min-description-length 10
 ```
 
+### Subject format
+
+By default the description must start with a lowercase letter. To allow
+uppercase descriptions:
+
+```bash
+commit-guard --no-require-lowercase
+```
+
+In `.commit-guard.toml`:
+
+```toml
+require-lowercase = false
+```
+
+By default trailing `.` is forbidden. To change the set of forbidden trailing
+characters (any character is valid, including space):
+
+```bash
+commit-guard --no-trailing-chars ".,"
+commit-guard --no-trailing-chars ".,!"
+```
+
+In `.commit-guard.toml`:
+
+```toml
+no-trailing-chars = [".", "!"]
+```
+
+Pass an empty list to disable the check entirely:
+
+```toml
+no-trailing-chars = []
+```
+
 ### Type validation
 
 By default the standard conventional commit types are accepted. Use `--types`
@@ -149,7 +184,8 @@ independently of `--enable`/`--disable`.
 
 Place `.commit-guard.toml` in your project root (or any parent directory) to
 set defaults for `enable`, `disable`, `scopes`, `require-scope`, `types`,
-`max-subject-length`, `min-description-length`, and `require-trailers`.
+`max-subject-length`, `min-description-length`, `require-lowercase`,
+`no-trailing-chars`, and `require-trailers`.
 commit-guard searches upward from the working directory and uses the first
 file found.
 
@@ -161,6 +197,8 @@ require-scope = true
 types = ["feat", "fix", "chore", "wip"]
 max-subject-length = 100
 min-description-length = 10
+require-lowercase = false
+no-trailing-chars = [".", "!"]
 require-trailers = ["Closes", "Reviewed-by"]
 ```
 
@@ -170,7 +208,8 @@ enable = ["subject", "imperative"]
 ```
 
 CLI flags (`--enable`, `--disable`, `--scopes`, `--require-scope`, `--types`,
-`--max-subject-length`, `--min-description-length`, `--require-trailer`) take
+`--max-subject-length`, `--min-description-length`, `--no-require-lowercase`,
+`--no-trailing-chars`, `--require-trailer`) take
 full precedence and ignore config file values when provided.
 
 ### Environment variables
@@ -321,6 +360,8 @@ jobs:
           require-trailer: 'Closes,Reviewed-by'
           max-subject-length: '100'
           min-description-length: '10'
+          no-require-lowercase: 'true'
+          no-trailing-chars: '.,!'
           allow-empty: 'true'
           include-merges: 'true'
           output-file: results.jsonl

action.yml

@@ -34,6 +34,13 @@ inputs:
   min-description-length:
     description: Minimum description length in characters (default 0, off)
     required: false
+  no-require-lowercase:
+    description: Allow description to start with uppercase (default false)
+    required: false
+    default: 'false'
+  no-trailing-chars:
+    description: Forbidden trailing characters, comma-separated (default '.')
+    required: false
   allow-empty:
     description: Exit 0 when --range yields no commits
     required: false
@@ -75,6 +82,8 @@ runs:
         CG_TYPES: ${{ inputs.types }}
         CG_MAX_SUBJECT_LENGTH: ${{ inputs.max-subject-length }}
         CG_MIN_DESCRIPTION_LENGTH: ${{ inputs.min-description-length }}
+        CG_NO_REQUIRE_LOWERCASE: ${{ inputs.no-require-lowercase }}
+        CG_NO_TRAILING_CHARS: ${{ inputs.no-trailing-chars }}
         CG_ALLOW_EMPTY: ${{ inputs.allow-empty }}
         CG_INCLUDE_MERGES: ${{ inputs.include-merges }}
         CG_REQUIRE_TRAILER: ${{ inputs.require-trailer }}
@@ -92,6 +101,8 @@ runs:
             ARGS+=(--max-subject-length "$CG_MAX_SUBJECT_LENGTH")
         [[ -n "$CG_MIN_DESCRIPTION_LENGTH" ]] && \
             ARGS+=(--min-description-length "$CG_MIN_DESCRIPTION_LENGTH")
+        [[ "$CG_NO_REQUIRE_LOWERCASE" == "true" ]] && ARGS+=(--no-require-lowercase)
+        [[ -n "$CG_NO_TRAILING_CHARS" ]] && ARGS+=(--no-trailing-chars "$CG_NO_TRAILING_CHARS")
         [[ "$CG_ALLOW_EMPTY" == "true" ]] && ARGS+=(--allow-empty)
         [[ "$CG_INCLUDE_MERGES" == "true" ]] && ARGS+=(--include-merges)
         [[ -n "$CG_REQUIRE_TRAILER" ]] && ARGS+=(--require-trailer "$CG_REQUIRE_TRAILER")

docs/index.html

@@ -398,6 +398,8 @@ <h2>Configuration <a href="#configuration" class="anchor">#</a></h2>
 types = ["feat", "fix", "chore", "wip"]
 max-subject-length = 100
 min-description-length = 10
+require-lowercase = false
+no-trailing-chars = [".", "!"]
 require-trailers = ["Closes", "Reviewed-by"]</code></pre>
 
         <h3>Required trailers</h3>
@@ -492,8 +494,10 @@ <h2>GitHub Actions <a href="#github-actions" class="anchor">#</a></h2>
           <code>range</code>, <code>enable</code>, <code>disable</code>,
           <code>scopes</code>, <code>require-scope</code>, <code>types</code>,
           <code>max-subject-length</code>, <code>min-description-length</code>,
-          <code>require-trailer</code>, <code>allow-empty</code>,
-          <code>include-merges</code>, <code>output-file</code>.
+          <code>no-require-lowercase</code>, <code>no-trailing-chars</code>,
+          <code>require-trailer</code>,
+          <code>allow-empty</code>, <code>include-merges</code>,
+          <code>output-file</code>.
         </p>
 
         <p>

src/git_commit_guard/__init__.py

@@ -146,15 +146,17 @@ def _strip_comments(message):
     )
 
 
-def check_subject(  # noqa: PLR0913 Too many arguments in function definition (7 > 5)
+def check_subject(  # noqa: PLR0913 Too many arguments in function definition (9 > 5)
     line,
     result,
     allowed_scopes=frozenset(),
     allowed_types=TYPES,
     max_subject_length=MAX_SUBJECT_LEN,
     min_description_length=0,
+    no_trailing_chars=frozenset("."),
     *,
     require_scope=False,
+    require_lowercase=True,
 ):
     m = SUBJECT_RE.match(line)
     if not m:
@@ -174,10 +176,10 @@ def check_subject(  # noqa: PLR0913 Too many arguments in function definition (7
         result.error(f"unknown scope: {scope}", check=Check.SUBJECT)
 
     desc = m.group("desc")
-    if desc[0].isupper():
+    if require_lowercase and desc[0].isupper():
         result.error("description must not start with uppercase", check=Check.SUBJECT)
-    if desc.endswith("."):
-        result.error("description must not end with period", check=Check.SUBJECT)
+    if no_trailing_chars and desc[-1] in no_trailing_chars:
+        result.error(f"description must not end with {desc[-1]!r}", check=Check.SUBJECT)
     if len(line) > max_subject_length:
         result.error(
             f"subject too long: {len(line)} > {max_subject_length}", check=Check.SUBJECT
@@ -305,6 +307,8 @@ class Args:
     allowed_types: frozenset
     max_subject_length: int
     min_description_length: int
+    require_lowercase: bool
+    no_trailing_chars: frozenset
     rev_range: str | None
     allow_empty: bool
     include_merges: bool
@@ -345,6 +349,22 @@ def _resolve_min_description_length(args, config):
     return 0
 
 
+def _resolve_require_lowercase(args, config):
+    if args.require_lowercase is not None:
+        return args.require_lowercase
+    if "require-lowercase" in config:
+        return config["require-lowercase"]
+    return True
+
+
+def _resolve_no_trailing_chars(args, config):
+    if args.no_trailing_chars is not None:
+        return frozenset(c for c in args.no_trailing_chars.split(",") if c)
+    if "no-trailing-chars" in config:
+        return frozenset(config["no-trailing-chars"])
+    return frozenset(".")
+
+
 def _resolve_required_trailers(args, config):
     if args.require_trailer:
         return [t.strip() for t in args.require_trailer.split(",")]
@@ -431,6 +451,19 @@ def _parse_args():
         metavar="N",
         help="minimum description length in characters (default: 0, off)",
     )
+    parser.add_argument(
+        "--no-require-lowercase",
+        dest="require_lowercase",
+        action="store_false",
+        default=None,
+        help="allow description to start with uppercase (default: disallowed)",
+    )
+    parser.add_argument(
+        "--no-trailing-chars",
+        default=None,
+        metavar="CHAR[,CHAR,...]",
+        help="forbidden trailing characters in description (default: '.')",
+    )
     parser.add_argument(
         "--range",
         dest="rev_range",
@@ -473,6 +506,8 @@ def _parse_args():
     allowed_types = _resolve_types(args, config)
     max_subject_length = _resolve_max_subject_length(args, config)
     min_description_length = _resolve_min_description_length(args, config)
+    require_lowercase = _resolve_require_lowercase(args, config)
+    no_trailing_chars = _resolve_no_trailing_chars(args, config)
     required_trailers = _resolve_required_trailers(args, config)
 
     if args.allow_empty and not args.rev_range:
@@ -507,6 +542,8 @@ def _parse_args():
         allowed_types=allowed_types,
         max_subject_length=max_subject_length,
         min_description_length=min_description_length,
+        require_lowercase=require_lowercase,
+        no_trailing_chars=no_trailing_chars,
         rev_range=args.rev_range,
         allow_empty=args.allow_empty,
         include_merges=args.include_merges,
@@ -560,7 +597,9 @@ def _run_checks(args, rev, message, result):
             args.allowed_types,
             args.max_subject_length,
             args.min_description_length,
+            args.no_trailing_chars,
             require_scope=args.require_scope,
+            require_lowercase=args.require_lowercase,
         )
     if Check.IMPERATIVE in args.enabled:
         if desc is None:

tests/test_git_commit_guard.py

@@ -113,11 +113,41 @@ def test_uppercase_description(self):
         check_subject("fix: Add token", r)
         assert not r.ok
 
+    def test_uppercase_description_allowed(self):
+        r = Result()
+        check_subject("fix: Add token", r, require_lowercase=False)
+        assert r.ok
+
+    def test_lowercase_required_by_default(self):
+        r = Result()
+        check_subject("fix: add token", r)
+        assert r.ok
+
     def test_trailing_period(self):
         r = Result()
         check_subject("fix: add token.", r)
         assert not r.ok
 
+    def test_trailing_char_custom(self):
+        r = Result()
+        check_subject("fix: add token!", r, no_trailing_chars=frozenset("!"))
+        assert not r.ok
+
+    def test_trailing_char_space(self):
+        r = Result()
+        check_subject("fix: add token ", r, no_trailing_chars=frozenset(". "))
+        assert not r.ok
+
+    def test_trailing_chars_empty_disables_check(self):
+        r = Result()
+        check_subject("fix: add token.", r, no_trailing_chars=frozenset())
+        assert r.ok
+
+    def test_trailing_chars_multiple(self):
+        r = Result()
+        check_subject("fix: add token!", r, no_trailing_chars=frozenset(".!"))
+        assert not r.ok
+
     def test_subject_too_long(self):
         r = Result()
         check_subject("fix: " + "a" * 68, r)  # 73 chars total