feat: ライセンススナップショットのチェックと自動更新ワークフローを追加

Author: yuubinnkyoku

.gitattributes

@@ -0,0 +1,16 @@
+# Enforce LF endings for text files to avoid CRLF noise, especially in generated license snapshot
+* text=auto eol=lf
+
+# Explicitly enforce LF for the generated OSS licenses snapshot
+lib/generated/oss_licenses.dart text eol=lf
+
+# Keep binary files untouched
+*.png binary
+*.jpg binary
+*.jpeg binary
+*.ttf binary
+*.otf binary
+*.ico binary
+
+# Scripts (shell) also LF
+*.sh text eol=lf

.github/workflows/license_snapshot.yml

@@ -0,0 +1,57 @@
+name: License Snapshot Check
+
+on:
+  pull_request:
+    branches: [ main, fix/** ]
+    paths:
+      - 'pubspec.yaml'
+      - 'pubspec.lock'
+      - 'lib/generated/oss_licenses.dart'
+      - '.github/workflows/license_snapshot.yml'
+  push:
+    branches: [ main ]
+    paths:
+      - 'pubspec.yaml'
+      - 'pubspec.lock'
+      - 'lib/generated/oss_licenses.dart'
+      - '.github/workflows/license_snapshot.yml'
+  workflow_dispatch: {}
+
+jobs:
+  license-diff:
+    name: Verify generated OSS licenses snapshot is up-to-date
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Set up Flutter (stable)
+        uses: subosito/flutter-action@v2
+        with:
+          channel: 'stable'
+          cache: true
+
+      - name: Pub get
+        run: flutter pub get
+
+      - name: Generate license snapshot
+        run: >-
+          dart run flutter_oss_licenses:generate
+          --output lib/generated/oss_licenses.dart
+
+      - name: Check diff
+        run: |
+          if git diff --name-only --exit-code lib/generated/oss_licenses.dart; then
+            echo "License snapshot is up-to-date.";
+          else
+            echo '::error file=lib/generated/oss_licenses.dart::License snapshot is outdated. Run:';
+            echo 'dart run flutter_oss_licenses:generate --output lib/generated/oss_licenses.dart';
+            echo 'and commit the result.';
+            exit 1;
+          fi
+
+      - name: Show diff (only when failed previously)
+        if: failure()
+        run: git --no-pager diff lib/generated/oss_licenses.dart

.github/workflows/license_snapshot_autoupdate.yml

@@ -0,0 +1,70 @@
+name: License Snapshot Auto-Update
+
+on:
+  schedule:
+    # 毎日 03:15 UTC (日本時間 12:15 JST頃) 実行。GitHub Actions は分散なので多少の誤差あり。
+    - cron: '15 3 * * *'
+  workflow_dispatch: {}
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  update-license-snapshot:
+    name: Generate & Auto PR (oss licenses)
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Set up Flutter (stable)
+        uses: subosito/flutter-action@v2
+        with:
+          channel: 'stable'
+          cache: true
+
+      - name: Pub get
+        run: flutter pub get
+
+      - name: Re-generate license snapshot
+        run: >-
+          dart run flutter_oss_licenses:generate
+          --output lib/generated/oss_licenses.dart
+
+      - name: Detect changes
+        id: diff
+        run: |
+          if git diff --quiet --exit-code lib/generated/oss_licenses.dart; then
+            echo "changed=false" >> $GITHUB_OUTPUT
+          else
+            echo "changed=true" >> $GITHUB_OUTPUT
+          fi
+
+      - name: Create Pull Request
+        if: steps.diff.outputs.changed == 'true'
+        uses: peter-evans/create-pull-request@v6
+        with:
+          commit-message: 'chore(licenses): update oss licenses snapshot'
+          title: 'chore(licenses): update oss licenses snapshot'
+          body: |
+            自動生成ワークフローにより `lib/generated/oss_licenses.dart` を更新しました。
+
+            - 依存追加/更新/削除を検出
+            - コミット時刻: ${{ github.run_id }}
+
+            マージ後、手動のライセンス差分チェック (#license_snapshot.yml) も最新となります。
+          branch: ci/update-oss-licenses
+          delete-branch: true
+          add-paths: |
+            lib/generated/oss_licenses.dart
+          labels: |
+            chore
+            automation
+
+      - name: No changes summary
+        if: steps.diff.outputs.changed != 'true'
+        run: echo "No license snapshot changes detected."