fixup! test: add opt-in process WPT runner

Author: panva

test/parallel/test-common-wpt-backends.js

@@ -77,11 +77,17 @@ async function collect(backend, throws) {
 }
 
 async function compare(throws) {
-  // Compared as a set: an uncaught error reaches the runner over a different
-  // channel than the results do, so it can overtake them on the thread
-  // backend. The runner acts on each of these independently.
-  const thread = (await collect('thread', throws)).sort();
-  const child = (await collect('process', throws)).sort();
+  const comparable = async (backend) => {
+    const events = await collect(backend, throws);
+    // A worker thread keeps delivering messages after it throws, so `events`
+    // is copied here and only the error is compared; what the spec reports
+    // before throwing is covered by the run that completes normally.
+    const wanted = throws ? (event) => event.startsWith('uncaught ') : () => true;
+    return events.filter(wanted).sort();
+  };
+
+  const thread = await comparable('thread');
+  const child = await comparable('process');
   assert.notStrictEqual(thread.length, 0);
   assert.deepStrictEqual(thread, child);
   return thread;
@@ -112,10 +118,9 @@ async function main() {
   ]);
 
   const uncaught = await compare(true);
-  assert.ok(
-    uncaught.includes('uncaught Error: deliberate uncaught error | deliberate uncaught error'),
-    `uncaught error was not reported: ${uncaught.join(', ')}`,
-  );
+  assert.deepStrictEqual(uncaught, [
+    'uncaught Error: deliberate uncaught error | deliberate uncaught error',
+  ]);
 
   for (const [driver, spec] of [
     ['test-compression.js', 'compression-bad-chunks.any.js'],