Capture reason if zstd fails unexpectedly

pr-checks/checks/zstd-bundle-fallback.yml

@@ -0,0 +1,74 @@
+name: "Zstandard bundle fallback"
+description: "Tests the fallback for when downloading a Zstandard-compressed CodeQL Bundle fails"
+versions:
+  - linked
+operatingSystems:
+  - ubuntu
+env:
+  CODEQL_ACTION_ZSTD_BUNDLE: true
+  CODEQL_ACTION_FORCE_ZSTD_FAILURE: true
+steps:
+  - name: Remove CodeQL from toolcache
+    run: |
+      rm -rf $RUNNER_TOOL_CACHE/CodeQL
+  - id: init
+    uses: ./../action/init
+    with:
+      # Swift is not supported on Ubuntu so we manually exclude it from the list here
+      languages: cpp,csharp,go,java,javascript,python,ruby 
+      tools: ${{ steps.prepare-test.outputs.tools-url }}
+  - name: Build code
+    shell: bash
+    run: ./build.sh
+  - uses: ./../action/analyze
+    with:
+      output: ${{ runner.temp }}/results
+      upload-database: false
+  - name: Upload SARIF
+    uses: actions/upload-artifact@v3
+    with:
+      name: zstd-bundle.sarif
+      path: ${{ runner.temp }}/results/cpp.sarif
+      retention-days: 7
+  - name: Check expected diagnostics
+    uses: actions/github-script@v7
+    env:
+      SARIF_PATH: ${{ runner.temp }}/results/cpp.sarif
+    with:
+      script: |
+        const fs = require('fs');
+
+        const sarif = JSON.parse(fs.readFileSync(process.env['SARIF_PATH'], 'utf8'));
+        const run = sarif.runs[0];
+
+        const toolExecutionNotifications = run.invocations[0].toolExecutionNotifications;
+        const downloadTelemetryNotifications = toolExecutionNotifications.filter(n =>
+          n.descriptor.id === 'codeql-action/bundle-download-telemetry'
+        );
+        if (downloadTelemetryNotifications.length !== 1) {
+          core.setFailed(
+            'Expected exactly one reporting descriptor in the ' +
+              `'runs[].invocations[].toolExecutionNotifications[]' SARIF property, but found ` +
+              `${downloadTelemetryNotifications.length}. All notification reporting descriptors: ` +
+              `${JSON.stringify(toolExecutionNotifications)}.`
+          );
+        }
+
+        const toolsUrl = downloadTelemetryNotifications[0].properties.attributes.toolsUrl;
+        console.log(`Found tools URL: ${toolsUrl}`);
+
+        if (!toolsUrl.endsWith('.tar.gz')) {
+          core.setFailed(
+            `Expected the tools URL to be a .tar.gz file, but found '${toolsUrl}'.`
+          );
+        }
+
+        const zstdFailureReason = downloadTelemetryNotifications[0].properties.attributes.zstdFailureReason;
+        console.log(`Found zstd failure reason: ${zstdFailureReason}`);
+
+        const expectedZstdFailureReason = 'Failing since CODEQL_ACTION_FORCE_ZSTD_FAILURE is true.';
+        if (zstdFailureReason !== expectedZstdFailureReason) {
+          core.setFailed(
+            `Expected the zstd failure reason to be '${expectedZstdFailureReason}', but found '${zstdFailureReason}'.`
+          );
+        }