feat: derive release bump only from the title bang marker (#268)

The release workflow scanned the PR title and body for "BREAKING CHANGE(S)"
and forced a major bump on any match. Prose that merely mentioned the phrase,
including a sentence stating there was no breaking change, tripped it. This is
the same footgun that mis-cut a major in getstream-ruby.

Treat the `\!` marker in the conventional-commits title (e.g. `feat\!:`) as the
sole breaking-change signal and stop reading the PR body entirely. Drop the
now-unused --body / --body-file options and the body plumbing in release.yml.

Author: mogita

.github/workflows/release.yml

@@ -64,13 +64,9 @@ jobs:
         if: github.event_name == 'pull_request' && steps.already_released.outputs.value != 'true'
         env:
           PR_TITLE: ${{ github.event.pull_request.title }}
-          PR_BODY: ${{ github.event.pull_request.body }}
         run: |
-          PR_BODY_FILE=$(mktemp)
-          printf '%s' "$PR_BODY" > "$PR_BODY_FILE"
           python3 scripts/release/bump_version.py \
             --title "$PR_TITLE" \
-            --body-file "$PR_BODY_FILE" \
             --output "$GITHUB_OUTPUT"
 
       - name: Determine version bump (manual)

scripts/release/bump_version.py

@@ -65,12 +65,11 @@ def find_latest_semver_tag() -> str:
     return "{}.{}.{}".format(*versions[-1])
 
 
-def determine_bump_type(title: str, body: str) -> str:
+def determine_bump_type(title: str) -> str:
+    # Breaking changes are signalled only by the `!` marker in the title
+    # (e.g. `feat!:`). Free-text body/title prose is not trusted: a PR that
+    # merely mentions "BREAKING CHANGE" must not force a major bump.
     title = title.strip()
-    body = body.strip()
-    breaking_re = re.compile(r"BREAKING[ -]CHANGES?", re.IGNORECASE)
-    if breaking_re.search(title) or breaking_re.search(body):
-        return "major"
     match = re.match(r"^([a-zA-Z]+)(\([^)]+\))?(!)?:", title)
     if not match:
         return "none"
@@ -119,12 +118,6 @@ def parse_bool(value: str) -> bool:
     return value.strip().lower() == "true"
 
 
-def resolve_body(args: argparse.Namespace) -> str:
-    if args.body_file:
-        return Path(args.body_file).read_text(encoding="utf-8")
-    return args.body or ""
-
-
 def write_outputs(output_path: str, entries: dict[str, str]) -> None:
     if not output_path:
         for key, value in entries.items():
@@ -138,8 +131,6 @@ def write_outputs(output_path: str, entries: dict[str, str]) -> None:
 def main() -> int:
     parser = argparse.ArgumentParser()
     parser.add_argument("--title", default="")
-    parser.add_argument("--body", default="")
-    parser.add_argument("--body-file", dest="body_file", default="")
     parser.add_argument("--output", default="")
     parser.add_argument("--manual-bump", dest="manual_bump", default="")
     parser.add_argument(
@@ -174,8 +165,7 @@ def main() -> int:
         )
         return 0
 
-    body = resolve_body(args)
-    bump = determine_bump_type(args.title, body)
+    bump = determine_bump_type(args.title)
     if bump == "none":
         write_outputs(
             args.output,