Automate release creation on package version bumps

Author: koszti

.github/workflows/release-on-version-bump.yml

@@ -0,0 +1,80 @@
+name: Release on Version Bump
+
+on:
+  push:
+    branches:
+      - main
+
+permissions:
+  contents: write
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v5
+        with:
+          fetch-depth: 0
+
+      - name: Detect version bump
+        id: version
+        run: |
+          set -euo pipefail
+
+          NEW_VERSION=$(jq -r .version precise/package.json)
+
+          if git show HEAD^:precise/package.json >/tmp/previous-package.json 2>/dev/null; then
+            PREVIOUS_VERSION=$(jq -r .version /tmp/previous-package.json)
+          else
+            PREVIOUS_VERSION=""
+          fi
+
+          {
+            echo "new_version=$NEW_VERSION"
+            echo "previous_version=$PREVIOUS_VERSION"
+          } >> "$GITHUB_OUTPUT"
+
+          if [ "$NEW_VERSION" = "$PREVIOUS_VERSION" ]; then
+            echo "bumped=false" >> "$GITHUB_OUTPUT"
+            echo "No version bump detected; skipping release creation."
+            exit 0
+          fi
+
+          echo "bumped=true" >> "$GITHUB_OUTPUT"
+
+      - name: Generate changelog
+        id: changelog
+        if: steps.version.outputs.bumped == 'true'
+        run: |
+          set -euo pipefail
+
+          PREVIOUS_TAG=$(git tag --list "*.*.*" --sort=-v:refname | head -n 1 || true)
+
+          if [ -n "$PREVIOUS_TAG" ]; then
+            RANGE="${PREVIOUS_TAG}..HEAD"
+            LOG=$(git log --no-merges --pretty=format:"- %s (%h)" "$RANGE")
+          else
+            LOG=$(git log --no-merges --pretty=format:"- %s (%h)")
+          fi
+
+          if [ -z "$LOG" ]; then
+            LOG="Changelog not available."
+          fi
+
+          {
+            echo "changelog<<'EOF'"
+            echo "$LOG"
+            echo "EOF"
+          } >> "$GITHUB_OUTPUT"
+
+      - name: Create GitHub release
+        if: steps.version.outputs.bumped == 'true'
+        uses: softprops/action-gh-release@v2
+        with:
+          tag_name: ${{ steps.version.outputs.new_version }}
+          name: ${{ steps.version.outputs.new_version }}
+          body: ${{ steps.changelog.outputs.changelog }}
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}