Fix action failure behavior and exit code capture

.github/workflows/test-action.yml

@@ -1,10 +1,10 @@
 name: Test GitHub Action
 
 # This workflow tests all features of the Python Linting GitHub Action
 # It validates that all action inputs work correctly and that the action
 # properly executes linting tools and badge generation
 
 on:
   pull_request:
     branches: [ main ]
     paths:
@@ -310,6 +310,67 @@
         with:
           python-version: ${{ matrix.python-version }}
 
+  # Test that action fails when linting fails
+  test-failure-behavior:
+    name: Test Failure Behavior
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write  # Need write to test badge commits
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v5
+
+      - name: Create badly formatted Python file
+        run: |
+          mkdir -p test_project
+          cat > test_project/bad_code.py << 'EOF'
+          """Badly formatted Python file to test failure behavior."""
+
+          def badly_formatted(  ):
+              x=1+2
+              y  =  3  +  4
+              return x+y
+
+          if __name__ == "__main__":
+              badly_formatted()
+          EOF
+
+      - name: Run Python Linting (Should Fail)
+        id: linting
+        uses: ./
+        with:
+          python-version: '3.11'
+          black_options: '--check'
+          generate-badges: 'true'
+          badges-directory: '.github/test-failure-badges'
+          update-readme: 'false'
+        continue-on-error: true
+
+      - name: Verify action failed
+        run: |
+          if [ "${{ steps.linting.outcome }}" != "failure" ]; then
+            echo "❌ Error: Action should have failed but didn't"
+            echo "Outcome was: ${{ steps.linting.outcome }}"
+            exit 1
+          fi
+          echo "✓ Action correctly failed when linting failed"
+
+      - name: Verify badges were still generated
+        run: |
+          if [ ! -f .github/test-failure-badges/black.svg ]; then
+            echo "❌ Error: Badges not generated even though they should always be created"
+            exit 1
+          fi
+          echo "✓ Badges were generated even though linting failed"
+
+          # Verify the badge shows failure status (contains 'failing' text)
+          if ! grep -q "failing" .github/test-failure-badges/black.svg; then
+            echo "❌ Error: Badge does not indicate failure"
+            cat .github/test-failure-badges/black.svg
+            exit 1
+          fi
+          echo "✓ Badge correctly shows failing status"
+
   # Final summary
   test-summary:
     name: Test Summary
@@ -324,6 +385,7 @@
       - test-readme-update
       - test-update-badges-script
       - test-python-versions
+      - test-failure-behavior
     steps:
       - name: All tests passed
         run: |
@@ -337,3 +399,5 @@
           echo "  ✓ README updates"
           echo "  ✓ update_badges.py script"
           echo "  ✓ Multiple Python versions (3.9-3.12)"
+          echo "  ✓ Failure behavior (action fails when linting fails)"
+          echo "  ✓ Badge generation on failure"

README.md

@@ -67,6 +67,23 @@ When `update-readme` is enabled, the action will automatically insert badge refe
 ![MyPy](.github/badges/mypy.svg)
 ```
 
+## Behavior
+
+### Failure Handling
+
+The action is designed to provide comprehensive linting feedback while maintaining proper CI/CD semantics:
+
+1. **All linting tools always run**: Even if one tool fails, the others will still execute to provide complete feedback
+2. **Badges and README are always updated**: Badge generation and README updates happen regardless of linting results, ensuring status badges accurately reflect the current state
+3. **The action fails if any linting fails**: After all tools run and badges are updated, the action will fail with a non-zero exit code if any linting tool reported issues
+4. **Workflow stops on failure**: When the action fails, subsequent steps in your workflow will not execute (unless they use `if: always()` or `if: failure()`)
+
+This ensures that:
+- You get complete linting feedback in one run
+- Status badges are always up-to-date
+- Your CI/CD pipeline correctly reports failures
+- Failed linting prevents merges when using branch protection rules
+
 ## Inputs
 
 | Input | Description | Required | Default |

action.yml

@@ -81,7 +81,7 @@ runs:
     - name: Run Pylint
       run: |
         pylint ${{ inputs.pylint_options }} --reports=y --jobs=0 . 2>&1 | tee pylint_output.txt
-        echo "PYLINT_EXIT_CODE=$?" >> $GITHUB_ENV
+        echo "PYLINT_EXIT_CODE=${PIPESTATUS[0]}" >> $GITHUB_ENV
       shell: bash
       if: always()
       continue-on-error: true
@@ -101,7 +101,7 @@ runs:
     - name: Run Black
       run: |
         black --check ${{ inputs.black_options }} . 2>&1 | tee black_output.txt
-        echo "BLACK_EXIT_CODE=$?" >> $GITHUB_ENV
+        echo "BLACK_EXIT_CODE=${PIPESTATUS[0]}" >> $GITHUB_ENV
       shell: bash
       if: always()
       continue-on-error: true
@@ -121,7 +121,7 @@ runs:
     - name: Run MyPy
       run: |
         mypy ${{ inputs.mypy_options }} . 2>&1 | tee mypy_output.txt
-        echo "MYPY_EXIT_CODE=$?" >> $GITHUB_ENV
+        echo "MYPY_EXIT_CODE=${PIPESTATUS[0]}" >> $GITHUB_ENV
       shell: bash
       if: always()
       continue-on-error: true
@@ -253,4 +253,41 @@ runs:
       shell: bash
       if: always()
 
+    - name: Check linting results and fail if needed
+      run: |
+        echo "Checking linting results..."
+        FAILED=0
+
+        if [ "${PYLINT_EXIT_CODE:-0}" != "0" ]; then
+          echo "❌ Pylint failed with exit code ${PYLINT_EXIT_CODE}"
+          FAILED=1
+        else
+          echo "✓ Pylint passed"
+        fi
+
+        if [ "${BLACK_EXIT_CODE:-0}" != "0" ]; then
+          echo "❌ Black failed with exit code ${BLACK_EXIT_CODE}"
+          FAILED=1
+        else
+          echo "✓ Black passed"
+        fi
+
+        if [ "${MYPY_EXIT_CODE:-0}" != "0" ]; then
+          echo "❌ MyPy failed with exit code ${MYPY_EXIT_CODE}"
+          FAILED=1
+        else
+          echo "✓ MyPy passed"
+        fi
+
+        if [ "$FAILED" -eq 1 ]; then
+          echo ""
+          echo "❌ Linting failed. Please fix the issues above."
+          exit 1
+        else
+          echo ""
+          echo "✅ All linting checks passed!"
+        fi
+      shell: bash
+      if: always()
+