Make running Parcel fixtures more robust (#1041)

Author: mrm007

package.json

@@ -16,7 +16,7 @@
     "test:unit": "pnpm test:jest && pnpm test:vitest",
     "test:jest": "jest",
     "test:vitest": "vitest --watch=false",
-    "test:playwright": "playwright test",
+    "test:playwright": "NODE_OPTIONS=--no-experimental-fetch playwright test",
     "format": "prettier --write .",
     "lint": "manypkg check && prettier --check . && tsc",
     "copy-readme-to-packages": "ts-node scripts/copy-readme-to-packages",

test-helpers/src/startFixture/parcel.ts

@@ -39,6 +39,11 @@ export const startParcelFixture = async (
         return reject(err);
       }
 
+      if (buildEvent?.type === 'buildFailure') {
+        console.error('Build event diagnostics:', buildEvent.diagnostics);
+        return reject(buildEvent.diagnostics[0]);
+      }
+
       if (buildEvent?.type === 'buildSuccess') {
         const cssBundle = buildEvent.bundleGraph
           .getBundles()