Add test for erroring after having already postponed a previous sibling

This can trigger errors due to invalid injected scripts but doesn't actually
fail anything else. It's a noop.

Author: sebmarkbage

packages/react-dom/src/__tests__/ReactDOMFizzServer-test.js

@@ -7178,6 +7178,141 @@ describe('ReactDOMFizzServer', () => {
     );
   });
 
+  // @gate enablePostpone
+  it('can client render a boundary after having already postponed', async () => {
+    let prerendering = true;
+    let ssr = true;
+
+    function Postpone() {
+      if (prerendering) {
+        React.unstable_postpone();
+      }
+      return 'Hello';
+    }
+
+    function ServerError() {
+      if (ssr) {
+        throw new Error('server error');
+      }
+      return 'World';
+    }
+
+    function App() {
+      return (
+        <div>
+          <Suspense fallback="Loading1">
+            <Postpone />
+            <ServerError />
+          </Suspense>
+          <Suspense fallback="Loading2">
+            <Postpone />
+          </Suspense>
+        </div>
+      );
+    }
+
+    const prerenderErrors = [];
+    const prerendered = await ReactDOMFizzStatic.prerenderToNodeStream(
+      <App />,
+      {
+        onError(x) {
+          prerenderErrors.push(x.message);
+        },
+      },
+    );
+    expect(prerendered.postponed).not.toBe(null);
+
+    prerendering = false;
+
+    const ssrErrors = [];
+
+    const resumed = ReactDOMFizzServer.resumeToPipeableStream(
+      <App />,
+      JSON.parse(JSON.stringify(prerendered.postponed)),
+      {
+        onError(x) {
+          ssrErrors.push(x.message);
+        },
+      },
+    );
+
+    const windowErrors = [];
+    function globalError(e) {
+      windowErrors.push(e.message);
+    }
+    window.addEventListener('error', globalError);
+
+    // Create a separate stream so it doesn't close the writable. I.e. simple concat.
+    const preludeWritable = new Stream.PassThrough();
+    preludeWritable.setEncoding('utf8');
+    preludeWritable.on('data', chunk => {
+      writable.write(chunk);
+    });
+
+    await act(() => {
+      prerendered.prelude.pipe(preludeWritable);
+    });
+
+    expect(windowErrors).toEqual([]);
+
+    expect(getVisibleChildren(container)).toEqual(
+      <div>
+        {'Loading1'}
+        {'Loading2'}
+      </div>,
+    );
+
+    await act(() => {
+      resumed.pipe(writable);
+    });
+
+    expect(prerenderErrors).toEqual(['server error']);
+
+    // Since this errored, we shouldn't have to replay it.
+    expect(ssrErrors).toEqual([]);
+
+    expect(windowErrors).toEqual([]);
+
+    // Still loading...
+    expect(getVisibleChildren(container)).toEqual(
+      <div>
+        {'Loading1'}
+        {'Hello'}
+      </div>,
+    );
+
+    const recoverableErrors = [];
+
+    ssr = false;
+
+    await clientAct(() => {
+      ReactDOMClient.hydrateRoot(container, <App />, {
+        onRecoverableError(x) {
+          recoverableErrors.push(x.message);
+        },
+      });
+    });
+
+    expect(recoverableErrors).toEqual(
+      __DEV__
+        ? ['server error']
+        : [
+            'The server could not finish this Suspense boundary, likely due to an error during server rendering. Switched to client rendering.',
+          ],
+    );
+    expect(getVisibleChildren(container)).toEqual(
+      <div>
+        {'Hello'}
+        {'World'}
+        {'Hello'}
+      </div>,
+    );
+
+    expect(windowErrors).toEqual([]);
+
+    window.removeEventListener('error', globalError);
+  });
+
   // @gate enablePostpone
   it('can postpone in fallback', async () => {
     let prerendering = true;