fix: only store relevant properties of lighthouse audit

Currently we store the entire Lighthouse audit object in the report which increases the report size and can make the report hard to serialize. These changes only capture the properties we care about.

Author: crisbeto

runner/workers/serve-testing/lighthouse.ts

@@ -38,7 +38,19 @@ export async function getLighthouseData(
     const isAllowedDisplayMode = displayMode === 'binary' || displayMode === 'numeric';
 
     if (audit.score != null && isAllowedType && isAllowedDisplayMode) {
-      availableAudits.set(audit.id, audit);
+      availableAudits.set(audit.id, {
+        // Only capture the properties we care about in order to keep
+        // the report size small and avoid serialization errors.
+        id: audit.id,
+        score: audit.score,
+        title: audit.title,
+        displayValue: audit.displayValue ?? null,
+        description: audit.description,
+        explanation: audit.explanation ?? null,
+        scoreDisplayMode: displayMode,
+        numericValue: audit.numericValue ?? null,
+        numericUnit: audit.numericUnit ?? null,
+      });
     }
   }
 

runner/workers/serve-testing/worker-types.ts

@@ -66,7 +66,17 @@ export type ServeTestingWorkerResponseMessage =
   | ServeTestingProgressLogMessage
   | ServeTestingResultMessage;
 
-export type LighthouseAudit = LighthouseRunnerResult['lhr']['audits']['x']; // Lighthouse doesn't export this so we need to dig for it.
+export interface LighthouseAudit {
+  id: string;
+  score: number | null;
+  title: string;
+  displayValue: string | null;
+  description: string | null;
+  explanation: string | null;
+  scoreDisplayMode: 'numeric' | 'binary';
+  numericValue: number | null;
+  numericUnit: string | null;
+}
 
 export interface LighthouseCategory {
   id: string;