autotag-from-changelog: Add tag-created and tag outputs

CHANGELOG.md

@@ -17,6 +17,9 @@ Breaking changes are prefixed with "Breaking Change: ".
 
 ### Added
 
+- `autotag-from-changelog` now exposes `tag_created` and `tag` outputs so
+  callers can react to whether a new tag was pushed.
+- `expect_step_output` test helper for asserting GitHub Actions step outputs.
 - `get-workflow-ref` action: resolve the ref a caller used to invoke a reusable
   workflow by parsing the caller's workflow file — no API calls or extra
   permissions needed.

CLAUDE.md

@@ -61,6 +61,9 @@ sources `test_helpers.sh` and validates behavior.
   production scripts. Run each command on its own line so that `bash -e`
   (the default for GitHub Actions `run` steps) halts on failure and the
   return code is checked automatically.
+- Use snake_case for multi-word action output names (e.g., `tag_created`
+  instead of `tag-created`). Hyphens in output names are parsed as subtraction
+  in GitHub Actions expressions.
 - In workflow YAML files, always look up and use the latest major version of
   built-in GitHub Actions (e.g., `actions/checkout`, `actions/upload-artifact`).
   Do not rely on memorized version numbers — they go stale.
@@ -70,3 +73,7 @@ sources `test_helpers.sh` and validates behavior.
   on error paths without logging or returning the error. If ignoring an
   error is genuinely correct (e.g., best-effort cleanup), add a comment
   explaining why it's safe to ignore.
+
+## Commit messages
+- If a commit updates or adds a specific action, prefix the commit with that
+  action. 

autotag-from-changelog/action.yml

@@ -4,10 +4,18 @@ inputs:
   changelog-path:
     description: Path to the changelog file
     default: CHANGELOG.md
+outputs:
+  tag_created:
+    description: Whether a new tag was created ("true" or "false")
+    value: ${{ steps.autotag.outputs.tag_created }}
+  tag:
+    description: The tag that was created (empty if no tag was created)
+    value: ${{ steps.autotag.outputs.tag }}
 runs:
   using: composite
   steps:
-    - shell: bash
+    - id: autotag
+      shell: bash
       env:
         CHANGELOG_PATH: ${{ inputs.changelog-path }}
       run: ${{ github.action_path }}/auto-tag-release.sh

autotag-from-changelog/auto-tag-release.sh

@@ -52,6 +52,7 @@ parse_changelog "$changelog"
 # Check if the version string is empty.
 if [ -z "$version" ]; then
   echo "No released version found in CHANGELOG.md, skipping."
+  set_output "tag_created" "false"
   exit 0
 fi
 
@@ -71,6 +72,7 @@ if [ -n "$unreleased_content" ]; then
   # be tagged — if it isn't, something went wrong.
   if [ "$tag_exists" = true ]; then
     echo "Content under [Unreleased] and ${tag} already tagged, nothing to do."
+    set_output "tag_created" "false"
     exit 0
   else
     log_error "CHANGELOG.md has content under [Unreleased] but ${tag} is not tagged. Tag the previous release before adding new entries."
@@ -80,6 +82,7 @@ fi
 
 if [ "$tag_exists" = true ]; then
   echo "Tag ${tag} already exists, nothing to do."
+  set_output "tag_created" "false"
   exit 0
 fi
 
@@ -96,3 +99,5 @@ if [[ "$tag" =~ ^v([0-9]+)\.[0-9]+\.[0-9]+ ]]; then
   git push --force origin "$major_tag"
   log_notice "Updated ${major_tag} successfully"
 fi
+set_output "tag_created" "true"
+set_output "tag" "$tag"

autotag-from-changelog/auto-tag-release_test.sh

@@ -151,6 +151,9 @@ run_parse_test "parse: content before unreleased is ignored" "0.9.0" "true" CHAN
 # Integration tests
 # =============================================
 
+GITHUB_OUTPUT="$TMPDIR/github_output"
+export GITHUB_OUTPUT
+
 # --- Content under [Unreleased], previous version not tagged — should fail ---
 cat <<'EOF' > CHANGELOG.md
 ## [Unreleased]
@@ -172,8 +175,11 @@ cat <<'EOF' > CHANGELOG.md
 ## [1.0.0] - 2026-01-01
 EOF
 
+: > "$GITHUB_OUTPUT"
 expect_success_output "creates new tag" "Tagged v1.0.0 successfully" \
   env CHANGELOG_PATH=CHANGELOG.md "$SCRIPT_DIR/auto-tag-release.sh"
+expect_step_output "creates new tag — tag_created output" "tag_created" "true"
+expect_step_output "creates new tag — tag output" "tag" "v1.0.0"
 
 # Verify the tag was actually created
 if git rev-parse v1.0.0 >/dev/null; then
@@ -188,8 +194,10 @@ fi
 verify_major_tag_points_to v1 v1.0.0
 
 # --- Tag already exists — should skip ---
+: > "$GITHUB_OUTPUT"
 expect_success_output "tag already exists" "already exists" \
   env CHANGELOG_PATH=CHANGELOG.md "$SCRIPT_DIR/auto-tag-release.sh"
+expect_step_output "tag already exists — tag_created output" "tag_created" "false"
 
 # --- Content under [Unreleased], previous version already tagged — should pass ---
 cat <<'EOF' > CHANGELOG.md
@@ -210,8 +218,10 @@ cat <<'EOF' > CHANGELOG.md
 ## [Unreleased]
 EOF
 
+: > "$GITHUB_OUTPUT"
 expect_success_output "no released version" "No released version found" \
   env CHANGELOG_PATH=CHANGELOG.md "$SCRIPT_DIR/auto-tag-release.sh"
+expect_step_output "no released version — tag_created output" "tag_created" "false"
 
 # --- No [Unreleased] section — should skip ---
 cat <<'EOF' > CHANGELOG.md

test_helpers.sh

@@ -98,6 +98,29 @@ expect_failure_output() {
   _run_test "$name" "nonzero" "$expected_output" "$@"
 }
 
+# expect_step_output "test name" "key" "expected_value"
+# Asserts that GITHUB_OUTPUT contains key=expected_value.
+# Checks the last occurrence of the key so tests that reuse the same file work.
+expect_step_output() {
+  local name="$1" key="$2" expected="$3"
+  local actual=""
+  if [ ! -f "${GITHUB_OUTPUT}" ]; then
+    echo "FAIL: $name — GITHUB_OUTPUT file does not exist"
+    FAIL=$((FAIL + 1))
+    return
+  fi
+  if grep --quiet --fixed-strings "${key}=" "${GITHUB_OUTPUT}"; then
+    actual=$(grep --fixed-strings "${key}=" "${GITHUB_OUTPUT}" | tail -1 | cut -d= -f2-)
+  fi
+  if [ "$actual" = "$expected" ]; then
+    echo "PASS: $name"
+    PASS=$((PASS + 1))
+  else
+    echo "FAIL: $name — expected output $key=$expected, got '$actual'"
+    FAIL=$((FAIL + 1))
+  fi
+}
+
 print_results() {
   echo ""
   echo "Results: $PASS passed, $FAIL failed"