Include failed test goldens as artifacts for easier test fixing on github actions

.github/workflows/go-test.yml

@@ -81,12 +81,18 @@ jobs:
 
         # Add an extra short delay to allow datadog to flush metrics
         sleep 300 # 5 minutes
-    - name: Archive test results
+    - name: Upload test results json
       uses: actions/upload-artifact@v3
       if: success() || failure()
       with:
         name: test-results-{{ matrix.os }}.json
         path: /tmp/testrun.json
+    - name: Upload failed test goldens
+      uses: actions/upload-artifact@v3
+      if: success() || failure()
+      with:
+        name: test-goldens-{{ matrix.os }}
+        path: /tmp/test-goldens/
 
     # - name: Setup tmate session
     #   if: ${{ failure() }}

shared/testutils/testutils.go

@@ -370,6 +370,10 @@ func CompareGoldens(t testing.TB, out, goldenName string) {
 		}
 	}
 	if diff := cmp.Diff(string(expected), out); diff != "" {
+		if err := os.Mkdir("/tmp/test-goldens", os.ModePerm); err != nil {
+			log.Fatal(err)
+		}
+		require.NoError(t, os.WriteFile(path.Join("/tmp/test-goldens", goldenName), []byte(out), 0644))
 		if os.Getenv("HISHTORY_UPDATE_GOLDENS") == "" {
 			_, filename, line, _ := runtime.Caller(1)
 			t.Fatalf("hishtory golden mismatch for %s at %s:%d (-expected +got):\n%s\nactual=\n%s", goldenName, filename, line, diff, out)