fix(core): better error logging on SSR/dev failures + log stacktraces and error causes (#8872)

website/_dogfooding/_pages tests/crashTest.tsx

@@ -0,0 +1,46 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import React from 'react';
+import useDocusaurusContext from '@docusaurus/useDocusaurusContext';
+import Layout from '@theme/Layout';
+
+// We only crash the page if siteConfig.customFields.crashTest === true
+function useBoom(): boolean {
+  const {
+    siteConfig: {customFields},
+  } = useDocusaurusContext();
+
+  return (customFields as {crashTest?: boolean}).crashTest ?? false;
+}
+
+function boomRoot() {
+  throw new Error('Boom root');
+}
+
+function boomParent() {
+  try {
+    boomRoot();
+  } catch (err) {
+    throw new Error('Boom parent', {cause: err as Error});
+  }
+}
+
+function BoomComponent() {
+  const boom = useBoom();
+  return <>{boom && boomParent()}</>;
+}
+
+export default function CrashTestPage(): JSX.Element {
+  return (
+    <Layout>
+      {/* eslint-disable-next-line @docusaurus/prefer-docusaurus-heading */}
+      <h1>This crash if customFields.crashTest = true</h1>
+      <BoomComponent />
+    </Layout>
+  );
+}

website/_dogfooding/_pages tests/index.mdx

@@ -20,6 +20,7 @@ import Readme from "../README.mdx"
 
 ### Other tests
 
+- [Crash test](/tests/pages/crashTest)
 - [Code block tests](/tests/pages/code-block-tests)
 - [Link tests](/tests/pages/link-tests)
 - [Error boundary tests](/tests/pages/error-boundary-tests)

website/docusaurus.config.js

@@ -42,6 +42,11 @@ function getNextVersionName() {
    */
 }
 
+// Artificial way to crash the SSR rendering and test errors
+// See website/_dogfooding/_pages tests/crashTest.tsx
+// Test with: DOCUSAURUS_CRASH_TEST=true yarn build:website:fast
+const crashTest = process.env.DOCUSAURUS_CRASH_TEST === 'true';
+
 const isDev = process.env.NODE_ENV === 'development';
 
 const isDeployPreview =
@@ -139,6 +144,7 @@ const config = {
   onBrokenMarkdownLinks: 'warn',
   favicon: 'img/docusaurus.ico',
   customFields: {
+    crashTest,
     isDeployPreview,
     description:
       'An optimized site generator in React. Docusaurus helps you to move fast and write content. Build documentation websites, blogs, marketing pages, and more.',