Merge pull request #1443 from mattn/add-release-workflow

Add workflow to create releases on tag push

.github/workflows/release.yaml

diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
new file mode 100644
index 0000000..5db21a2
--- /dev/null
+++ b/.github/workflows/release.yaml
@@ -0,0 +1,38 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - 'v*'
+
+permissions:
+  contents: write
+
+concurrency:
+  group: release-${{ github.ref }}
+  cancel-in-progress: false
+
+jobs:
+  release:
+    name: Create release
+    runs-on: ubuntu-latest
+    steps:
+      - name: Create release with generated notes
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          set -euo pipefail
+          if output=$(gh release view "$GITHUB_REF_NAME" --repo "$GITHUB_REPOSITORY" 2>&1); then
+            echo "Release $GITHUB_REF_NAME already exists, skipping"
+            exit 0
+          elif ! grep -qi "release not found" <<< "$output"; then
+            # A lookup failure other than "not found" (auth, network, API)
+            # must not fall through to the create step.
+            echo "$output" >&2
+            exit 1
+          fi
+          gh release create "$GITHUB_REF_NAME" \
+            --repo "$GITHUB_REPOSITORY" \
+            --title "${GITHUB_REF_NAME#v}" \
+            --verify-tag \
+            --generate-notes