add example failing tests (courtesy robertbrignull)

.github/workflows/integration-testing.yml

@@ -150,3 +150,43 @@ jobs:
     - uses: ./../action/analyze
       env:
         TEST_MODE: true
+
+  # Test the behaviour when asked to scan a compiled language but no code is compiled
+  multi-language-repo_test-no-language-seen-during-build-java:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Move codeql-action
+        shell: bash
+        run: |
+          mkdir ../action
+          shopt -s dotglob
+          mv * ../action/
+          # Do not copy anything back, so there's nothing left to scan
+      - uses: ./../action/init
+        with:
+          languages: java
+      - uses: ./../action/analyze
+        env:
+          TEST_MODE: true
+
+  # Test the behaviour when asked to scan a non-compiled language but there is no code to scan
+  multi-language-repo_test-no-language-seen-during-build-javascript:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Move codeql-action
+        shell: bash
+        run: |
+          mkdir ../action
+          shopt -s dotglob
+          mv * ../action/
+          # Do not copy anything back, so there's nothing left to scan
+      - uses: ./../action/init
+        with:
+          languages: javascript
+      - uses: ./../action/analyze
+        env:
+          TEST_MODE: true