chore: fix Pyink GitHub Action to check on all changed .py files

Three fixes:
1. used "fetch-depth: 2" to ensure that files in all commits in the PR are checked
2. triggered by all changed ".py" files in the repo
3. merged the "check modified files" and "run Pyink" steps because $GITHUB_ENV cannot handle multi-line env vars without special treatment

PiperOrigin-RevId: 766793736

.github/workflows/pyink.yml

@@ -17,8 +17,7 @@ name: Check Pyink Formatting
 on:
   pull_request:
     paths:
-      - 'src/**/*.py'
+      - '**.py'
-      - 'tests/**/*.py'
       - 'pyproject.toml'
 
 jobs:
@@ -28,6 +27,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          fetch-depth: 2
 
       - name: Set up Python
         uses: actions/setup-python@v5
@@ -38,36 +39,31 @@ jobs:
         run: |
           pip install pyink
 
-      - name: Detect changed Python files
+      - name: Run pyink on changed files
-        id: detect_changes
+        id: run_pyink
         run: |
           git fetch origin ${{ github.base_ref }}
           CHANGED_FILES=$(git diff --diff-filter=ACMR --name-only origin/${{ github.base_ref }}...HEAD | grep -E '\.py$' || true)
-          echo "CHANGED_FILES=${CHANGED_FILES}" >> $GITHUB_ENV
+          if [ -n "$CHANGED_FILES" ]; then
-
+            echo "Changed Python files:"
-      - name: Run pyink on changed files
+            echo "$CHANGED_FILES"
-        if: env.CHANGED_FILES != ''
-        run: |
-          echo "Changed Python files:"
-          echo "$CHANGED_FILES"
-
-          # Run pyink --check
-          set +e
-          pyink --check --config pyproject.toml $CHANGED_FILES
-          RESULT=$?
-          set -e
-
-          if [ $RESULT -ne 0 ]; then
             echo ""
-            echo "❌ Pyink formatting check failed!"
+            FORMATTED_FILES=$(echo "$CHANGED_FILES" | tr '\n' ' ')
-            echo "👉 To fix formatting, run locally:"
+
-            echo ""
+            # Run pyink --check
-            echo "    pyink --config pyproject.toml $CHANGED_FILES"
+            set +e
-            echo ""
+            pyink --check --diff --config pyproject.toml $CHANGED_FILES
-            exit $RESULT
+            RESULT=$?
+            set -e
+            if [ $RESULT -ne 0 ]; then
+              echo ""
+              echo "❌ Pyink formatting check failed!"
+              echo "👉 To fix formatting, run locally:"
+              echo ""
+              echo "    pyink --config pyproject.toml $FORMATTED_FILES"
+              echo ""
+              exit $RESULT
+            fi
+          else
+            echo "No Python files changed. Skipping pyink check."
           fi
-
-      - name: No changed Python files detected
-        if: env.CHANGED_FILES == ''
-        run: |
-          echo "No Python files changed. Skipping pyink check."