Implement code check for tests and changes

Added checks for modified files and test presence before grading.

Author: kappsegla

.github/workflows/classroom.yml

@@ -179,8 +179,24 @@ jobs:
           distribution: 'temurin'
           java-version: '25'
 
+      - name: Check for modified files and test presence
+        id: code-check
+        run: |
+          # Check for test files
+          has_tests=$(find src/test/java -type f -name "*.java" | grep -q . && echo "true" || echo "false")
+
+          # Check for modified files in src folders
+          git fetch origin main
+          changed_files=$(git diff --name-only origin/main...HEAD | grep -E '^src/(main|test)/java/.*\.java$' || true)
+          has_changes=$(test -n "$changed_files" && echo "true" || echo "false")
+
+          echo "has_tests=$has_tests" >> $GITHUB_OUTPUT
+          echo "has_changes=$has_changes" >> $GITHUB_OUTPUT
+           echo "should_grade=$([[ $has_tests == 'true' && $has_changes == 'true' ]] && echo 'true' || echo 'false')" >> $GITHUB_OUTPUT
+
       - name: Compilation Check
         id: compilation-check
+        if: ${{ steps.code-check.outputs.has_tests == 'true' && steps.code-check.outputs.has_changes == 'true' }}
         uses: classroom-resources/autograding-command-grader@v1
         with:
           test-name: Compilation Check
@@ -190,6 +206,7 @@ jobs:
 
       - name: Tests
         id: basic-tests
+        if: ${{ steps.code-check.outputs.has_tests == 'true' && steps.code-check.outputs.has_changes == 'true' }}
         uses: classroom-resources/autograding-command-grader@v1
         with:
           test-name: Basic Tests
@@ -198,9 +215,15 @@ jobs:
           max-score: 1
 
       - name: Autograding Reporter
+        if: ${{ steps.code-check.outputs.should_grade == 'true' }}
         uses: classroom-resources/autograding-grading-reporter@v1
         env:
           COMPILATION-CHECK_RESULTS: "${{steps.compilation-check.outputs.result}}"
           BASIC-TESTS_RESULTS: "${{steps.basic-tests.outputs.result}}"
         with:
           runners: compilation-check,basic-tests
+
+      - name: Reporter Skipped Notice
+        if: ${{ steps.code-check.outputs.should_grade != 'true' }}
+        run: |
+          echo "🛑 Skipping reporter: No grading results available due to missing tests or unchanged code."