chore(ci): 🤖 improve changelog parsing (#947)

* chore: 🤖 make extract-changelog as a separate process to allow local extract output testing

* refactor: 💡 extract changelog with fallbacks

* fix: 🐛 all extract changelog error messages now redirect to stder

* chore: 🤖 remove redundant filter

Author: punkbit

.github/workflows/release-publisher.yml

@@ -158,20 +158,23 @@ jobs:
         id: changelog
         run: |
           VERSION="${{ steps.verify-merge.outputs.version }}"
+          CHANGELOG_PATH="CHANGELOG.md"
+          CHANGELOG_OUTPUT_TEMP_PATH="/tmp/changelog.txt"
+          FALLBACK_MSG="📝 See [CHANGELOG.md](./CHANGELOG.md) for details."
 
-          if [[ -f CHANGELOG.md ]]; then
-            CHANGELOG=$(awk "/## $VERSION/,/## [0-9]/" CHANGELOG.md | sed '1d;$d' | sed '/^$/d')
+          CHANGELOG=""
+          if [[ -f "$CHANGELOG_PATH" ]]; then
+            CHANGELOG=$(.scripts/bash/extract-changelog "$VERSION" "$CHANGELOG_PATH")
+          fi
 
-            if [[ -z "$CHANGELOG" ]]; then
-              CHANGELOG="📝 See [CHANGELOG.md](./CHANGELOG.md) for details."
-            fi
+          if [[ -n "$CHANGELOG" ]]; then
+            echo "$CHANGELOG" > "$CHANGELOG_OUTPUT_TEMP_PATH"
           else
-            CHANGELOG="No changelog available."
+            echo "No changelog available for version $VERSION." > "$CHANGELOG_OUTPUT_TEMP_PATH"
+            echo "" >> "$CHANGELOG_OUTPUT_TEMP_PATH"
+            echo "$FALLBACK_MSG" >> "$CHANGELOG_OUTPUT_TEMP_PATH"
           fi
 
-          # Try persist multiple lines
-          echo "$CHANGELOG" > /tmp/changelog.txt
-
       - name: Create GitHub Release
         if: steps.verify-merge.outputs.is_release == 'true'
         uses: softprops/action-gh-release@v1

.scripts/bash/extract-changelog

@@ -0,0 +1,47 @@
+#!/bin/bash
+
+if [[ $# -lt 1 ]]; then
+  echo "👹 Oops! Usage is extract-changelog <version> [changelog_file]" >&2
+  exit 1
+fi
+
+VERSION="$1"
+CHANGELOG_FILE="${2:-CHANGELOG.md}"
+
+if [[ -z "$VERSION" ]]; then
+  echo "👹 Oops! Version is empty" >&2
+  exit 1
+fi
+
+if [[ ! -f "$CHANGELOG_FILE" ]]; then
+  echo "👹 Oops! Changelog file not found: $CHANGELOG_FILE" >&2
+  exit 1
+fi
+
+# NOTE: Extract content between "## <version>" and the next "## <version>" header
+FOUND=false
+CHANGELOG=""
+
+while IFS= read -r line; do
+  if [[ "$line" == "## $VERSION" ]]; then
+    FOUND=true
+    continue
+  fi
+
+  if $FOUND; then
+    if [[ "$line" =~ ^##\ [0-9] ]]; then
+      break
+    fi
+    CHANGELOG+="$line"$'\n'
+  fi
+done < "$CHANGELOG_FILE"
+
+CHANGELOG="${CHANGELOG%$'\n'}"
+
+if [[ -z "$CHANGELOG" ]]; then
+  echo "No changelog content found for version $VERSION" >&2
+  exit 1
+fi
+
+# NOTE: Prevent GitHub mentioning user by replacing @username with `@username`
+echo "$CHANGELOG" | sed 's/@\([a-zA-Z0-9][a-zA-Z0-9-]*\)/`@\1`/g'