feat(core): specific error when dev server is stopped

package.json

@@ -99,9 +99,6 @@
   },
   "prettier": "@sanity/prettier-config",
   "devDependencies": {
-    "@babel/preset-env": "^7.24.7",
-    "@babel/preset-react": "^7.24.7",
-    "@babel/preset-typescript": "^7.24.7",
     "@google-cloud/storage": "^7.11.0",
     "@playwright/test": "1.44.1",
     "@repo/dev-aliases": "workspace:*",

packages/@repo/test-config/.depcheckrc.json

@@ -0,0 +1,8 @@
+{
+  "ignores": [
+    "@babel/preset-env",
+    "@babel/preset-react",
+    "@babel/preset-typescript",
+    "babel-plugin-transform-vite-meta-hot"
+  ]
+}

packages/@repo/test-config/jest/createJestConfig.mjs

@@ -1,9 +1,10 @@
 /* eslint-disable tsdoc/syntax */
 
-import devAliases from '@repo/dev-aliases'
-
 import path from 'node:path'
+
+import devAliases from '@repo/dev-aliases'
 import {escapeRegExp, omit} from 'lodash-es'
+
 import {resolveDirName} from './resolveDirName.mjs'
 
 const dirname = resolveDirName(import.meta.url)
@@ -71,7 +72,6 @@ export function createJestConfig(config = {}) {
     resolver: path.resolve(dirname, './resolver.cjs'),
     testEnvironment: path.resolve(dirname, './jsdom.jest.env.ts'),
     setupFiles: [...setupFiles, path.resolve(dirname, './setup.ts')],
-    // testEnvironment: 'jsdom',
     testEnvironmentOptions: {
       url: 'http://localhost:3333',
     },
@@ -103,6 +103,7 @@ export function createJestConfig(config = {}) {
             '@babel/preset-typescript',
             ['@babel/preset-react', {runtime: 'automatic'}],
           ],
+          plugins: ['babel-plugin-transform-vite-meta-hot'],
         },
       ],
     },

packages/@repo/test-config/package.json

@@ -9,8 +9,12 @@
     "./vitest": "./vitest/index.mjs"
   },
   "devDependencies": {
+    "@babel/preset-env": "^7.24.7",
+    "@babel/preset-react": "^7.24.7",
+    "@babel/preset-typescript": "^7.24.7",
     "@jest/globals": "^29.7.0",
     "@repo/dev-aliases": "workspace:*",
+    "babel-plugin-transform-vite-meta-hot": "^1.0.0",
     "dotenv": "^16.4.5",
     "jest-environment-jsdom": "^29.7.0",
     "lodash-es": "^4.17.21",

packages/sanity/src/core/error/ErrorLogger.tsx

@@ -64,5 +64,9 @@ function isKnownError(err: Error): boolean {
     return true
   }
 
+  if ('ViteDevServerStoppedError' in err && err.ViteDevServerStoppedError) {
+    return true
+  }
+
   return false
 }

packages/sanity/src/core/studio/StudioErrorBoundary.tsx

@@ -11,7 +11,14 @@ import {
   Stack,
   Text,
 } from '@sanity/ui'
-import {type ComponentType, type ErrorInfo, type ReactNode, useCallback, useState} from 'react'
+import {
+  type ComponentType,
+  type ErrorInfo,
+  lazy,
+  type ReactNode,
+  useCallback,
+  useState,
+} from 'react'
 import {ErrorActions, isDev, isProd} from 'sanity'
 import {styled} from 'styled-components'
 import {useHotModuleReload} from 'use-hot-module-reload'
@@ -22,6 +29,17 @@ import {CorsOriginError} from '../store'
 import {isRecord} from '../util'
 import {CorsOriginErrorScreen, SchemaErrorsScreen} from './screens'
 
+/**
+ * The DevServerStoppedErrorScreen will always have been lazy loaded to client
+ * in instances where it is used, since DevServerStoppedError is only thrown
+ * when this module is loaded, and this screen is also conditional on this error type
+ */
+const DevServerStoppedErrorScreen = lazy(() =>
+  import('./ViteDevServerStopped').then((DevServerStopped) => ({
+    default: DevServerStopped.DevServerStoppedErrorScreen,
+  })),
+)
+
 interface StudioErrorBoundaryProps {
   children: ReactNode
   heading?: string
@@ -80,6 +98,10 @@ export const StudioErrorBoundary: ComponentType<StudioErrorBoundaryProps> = ({
     return <SchemaErrorsScreen schema={error.schema} />
   }
 
+  if (error && 'ViteDevServerStoppedError' in error && error.ViteDevServerStoppedError) {
+    return <DevServerStoppedErrorScreen />
+  }
+
   if (!error) {
     return <ErrorBoundary onCatch={handleCatchError}>{children}</ErrorBoundary>
   }

packages/sanity/src/core/studio/StudioLayout.tsx

@@ -1,7 +1,7 @@
 /* eslint-disable i18next/no-literal-string, @sanity/i18n/no-attribute-template-literals */
 import {Card, Flex} from '@sanity/ui'
 import {startCase} from 'lodash'
-import {Suspense, useCallback, useEffect, useMemo, useState} from 'react'
+import {lazy, Suspense, useCallback, useEffect, useMemo, useState} from 'react'
 import {NavbarContext} from 'sanity/_singletons'
 import {RouteScope, useRouter, useRouterState} from 'sanity/router'
 import {styled} from 'styled-components'
@@ -18,6 +18,14 @@ import {
 import {StudioErrorBoundary} from './StudioErrorBoundary'
 import {useWorkspace} from './workspace'
 
+const DetectViteDevServerStopped = lazy(() =>
+  import('./ViteDevServerStopped').then((DevServerStopped) => ({
+    default: DevServerStopped.DetectViteDevServerStopped,
+  })),
+)
+
+const detectViteDevServerStopped = import.meta.hot && process.env.NODE_ENV === 'development'
+
 const SearchFullscreenPortalCard = styled(Card)`
   height: 100%;
   left: 0;
@@ -173,6 +181,7 @@ export function StudioLayoutComponent() {
       {/* By using the tool name as the key on the error boundary, we force it to re-render
           when switching tools, which ensures we don't show the wrong tool having crashed */}
       <StudioErrorBoundary key={activeTool?.name} heading={`The ${activeTool?.name} tool crashed`}>
+        {detectViteDevServerStopped && <DetectViteDevServerStopped />}
         <Card flex={1} hidden={searchFullscreenOpen}>
           {activeTool && activeToolName && (
             <RouteScope

packages/sanity/src/core/studio/ViteDevServerStopped.tsx

@@ -0,0 +1,69 @@
+/* eslint-disable i18next/no-literal-string -- will not support i18n in error boundaries */
+import {Card, Container, Heading, Stack, Text} from '@sanity/ui'
+import {type ReactNode, useCallback, useEffect, useState} from 'react'
+import {type ViteHotContext} from 'vite/types/hot.js'
+
+const ERROR_TITLE = 'Dev server stopped'
+const ERROR_DESCRIPTION =
+  'The development server has stopped. You may need to restart it to continue working.'
+
+class ViteDevServerStoppedError extends Error {
+  ViteDevServerStoppedError: boolean
+
+  constructor() {
+    super(ERROR_TITLE)
+    this.name = 'ViteDevServerStoppedError'
+    this.ViteDevServerStoppedError = true
+  }
+}
+const serverHot = import.meta.hot
+const isViteServer = (hot: unknown): hot is ViteHotContext => Boolean(hot)
+
+const useDetectViteDevServerStopped = () => {
+  const [devServerStopped, setDevServerStopped] = useState(false)
+
+  const markDevServerStopped = useCallback(() => setDevServerStopped(true), [])
+
+  useEffect(() => {
+    // no early return to optimize tree-shaking
+    if (isViteServer(serverHot)) {
+      serverHot.on('vite:ws:disconnect', markDevServerStopped)
+    }
+  }, [markDevServerStopped])
+
+  return {devServerStopped}
+}
+
+const ThrowViteServerStopped = () => {
+  const {devServerStopped} = useDetectViteDevServerStopped()
+
+  if (devServerStopped) throw new ViteDevServerStoppedError()
+
+  return null
+}
+
+export const DetectViteDevServerStopped = (): ReactNode =>
+  isViteServer(serverHot) ? <ThrowViteServerStopped /> : null
+
+export const DevServerStoppedErrorScreen = (): ReactNode => (
+  <Card
+    height="fill"
+    overflow="auto"
+    paddingY={[4, 5, 6, 7]}
+    paddingX={4}
+    sizing="border"
+    tone="critical"
+  >
+    <Container width={3}>
+      <Stack space={4}>
+        <Heading>{ERROR_TITLE}</Heading>
+
+        <Card border radius={2} overflow="auto" padding={4} tone="inherit">
+          <Stack space={4}>
+            <Text size={2}>{ERROR_DESCRIPTION}</Text>
+          </Stack>
+        </Card>
+      </Stack>
+    </Container>
+  </Card>
+)