Sourcemap errors in terminal by default

packages/next/src/client/components/react-dev-overlay/server/shared.ts

@@ -50,7 +50,7 @@ export function findSourcePackage({
 export function getOriginalCodeFrame(
   frame: StackFrame,
   source: string | null
-): string | null | undefined {
+): string | null {
   if (!source || isInternal(frame.file)) {
     return null
   }
@@ -65,6 +65,7 @@ export function getOriginalCodeFrame(
         column: frame.column ?? 0,
       },
     },
+    // TODO: Only in TTY
     { forceColor: true }
   )
 }

packages/next/src/server/node-environment-extensions/error-inspect.tsx

@@ -0,0 +1,3 @@
+import { patchErrorInspect } from '../patch-error-inspect'
+
+patchErrorInspect()

packages/next/src/server/node-environment.ts

@@ -1,6 +1,9 @@
 // This file should be imported before any others. It sets up the environment
 // for later imports to work properly.
 
+// Import before anything else so that unexpected errors in other extensions are properly formatted.
+import './node-environment-extensions/error-inspect'
+
 import './node-environment-baseline'
 import './node-environment-extensions/random'
 import './node-environment-extensions/date'

packages/next/src/server/patch-error-inspect.ts

@@ -0,0 +1,228 @@
+import { findSourceMap } from 'module'
+import type * as util from 'util'
+import { SourceMapConsumer as SyncSourceMapConsumer } from 'next/dist/compiled/source-map'
+import type { StackFrame } from 'next/dist/compiled/stacktrace-parser'
+import { parseStack } from '../client/components/react-dev-overlay/server/middleware'
+import { getOriginalCodeFrame } from '../client/components/react-dev-overlay/server/shared'
+
+// TODO: Implement for Edge runtime
+const inspectSymbol = Symbol.for('nodejs.util.inspect.custom')
+
+function frameToString(frame: StackFrame): string {
+  let sourceLocation = frame.lineNumber !== null ? `:${frame.lineNumber}` : ''
+  if (frame.column !== null && sourceLocation !== '') {
+    sourceLocation += `:${frame.column}`
+  }
+  return frame.methodName
+    ? `    at ${frame.methodName} (${frame.file}${sourceLocation})`
+    : `    at ${frame.file}${frame.lineNumber}:${frame.column}`
+}
+
+function computeErrorName(error: Error): string {
+  // TODO: Node.js seems to use a different algorithm
+  // class ReadonlyRequestCookiesError extends Error {}` would read `ReadonlyRequestCookiesError: [...]`
+  // in the stack i.e. seems like under certain conditions it favors the constructor name.
+  return error.name || 'Error'
+}
+
+function prepareUnsourcemappedStackTrace(
+  error: Error,
+  structuredStackTrace: any[]
+): string {
+  const name = computeErrorName(error)
+  const message = error.message || ''
+  let stack = name + ': ' + message
+  for (let i = 0; i < structuredStackTrace.length; i++) {
+    stack += '\n    at ' + structuredStackTrace[i].toString()
+  }
+  return stack
+}
+
+function shouldIgnoreListByDefault(file: string): boolean {
+  return (
+    // TODO: Solve via `ignoreList` instead. Tricky because node internals are not part of the sourcemap.
+    file.startsWith('node:')
+    // C&P from setup-dev-bundler
+    // TODO: Taken from setup-dev-bundler but these seem too broad
+    // file.includes('web/adapter') ||
+    // file.includes('web/globals') ||
+    // file.includes('sandbox/context') ||
+    // TODO: Seems too aggressive?
+    // file.includes('<anonymous>') ||
+    // file.startsWith('eval')
+  )
+}
+
+function getSourcemappedFrameIfPossible(
+  frame: StackFrame,
+  sourcemapConsumers: Map<string, SyncSourceMapConsumer>
+): {
+  stack: StackFrame
+  // DEV only
+  code: string | null
+} | null {
+  if (frame.file === null) {
+    return null
+  }
+
+  let sourcemap = sourcemapConsumers.get(frame.file)
+  if (sourcemap === undefined) {
+    const moduleSourcemap = findSourceMap(frame.file)
+    if (moduleSourcemap === undefined) {
+      return null
+    }
+    sourcemap = new SyncSourceMapConsumer(
+      // @ts-expect-error -- Module.SourceMap['version'] is number but SyncSourceMapConsumer wants a string
+      moduleSourcemap.payload
+    )
+    sourcemapConsumers.set(frame.file, sourcemap)
+  }
+
+  const sourcePosition = sourcemap.originalPositionFor({
+    column: frame.column ?? 0,
+    line: frame.lineNumber ?? 1,
+  })
+
+  if (sourcePosition.source === null) {
+    return null
+  }
+
+  const sourceContent: string | null =
+    sourcemap.sourceContentFor(
+      sourcePosition.source,
+      /* returnNullOnMissing */ true
+    ) ?? null
+
+  const originalFrame: StackFrame = {
+    methodName:
+      sourcePosition.name ||
+      // default is not a valid identifier in JS so webpack uses a custom variable when it's an unnamed default export
+      // Resolve it back to `default` for the method name if the source position didn't have the method.
+      frame.methodName
+        ?.replace('__WEBPACK_DEFAULT_EXPORT__', 'default')
+        ?.replace('__webpack_exports__.', ''),
+    column: sourcePosition.column,
+    file: sourcePosition.source,
+    lineNumber: sourcePosition.line,
+    // TODO: c&p from async createOriginalStackFrame but why not frame.arguments?
+    arguments: [],
+  }
+
+  const codeFrame =
+    process.env.NODE_ENV !== 'production'
+      ? getOriginalCodeFrame(originalFrame, sourceContent)
+      : null
+
+  return {
+    stack: originalFrame,
+    code: codeFrame,
+  }
+}
+
+function parseAndSourceMap(error: Error): string {
+  // We overwrote Error.prepareStackTrace earlier so error.stack is not sourcemapped.
+  let unparsedStack = String(error.stack)
+  // We could just read it from `error.stack`.
+  // This works around cases where a 3rd party `Error.prepareStackTrace` implementation
+  // doesn't implement the name computation correctly.
+  const errorName = computeErrorName(error)
+
+  let idx = unparsedStack.indexOf('react-stack-bottom-frame')
+  if (idx !== -1) {
+    idx = unparsedStack.lastIndexOf('\n', idx)
+  }
+  if (idx !== -1) {
+    // Cut off everything after the bottom frame since it'll be React internals.
+    unparsedStack = unparsedStack.slice(0, idx)
+  }
+
+  const unsourcemappedStack = parseStack(unparsedStack)
+  const sourcemapConsumers = new Map<string, SyncSourceMapConsumer>()
+
+  let sourceMappedStack = ''
+  let sourceFrameDEV: null | string = null
+  for (const frame of unsourcemappedStack) {
+    if (frame.file === null) {
+      sourceMappedStack += '\n' + frameToString(frame)
+    } else if (!shouldIgnoreListByDefault(frame.file)) {
+      const sourcemappedFrame = getSourcemappedFrameIfPossible(
+        frame,
+        sourcemapConsumers
+      )
+
+      if (sourcemappedFrame === null) {
+        sourceMappedStack += '\n' + frameToString(frame)
+      } else {
+        // TODO: Use the first frame that's not ignore-listed
+        if (
+          process.env.NODE_ENV !== 'production' &&
+          sourcemappedFrame.code !== null &&
+          sourceFrameDEV !== null
+        ) {
+          sourceFrameDEV = sourcemappedFrame.code
+        }
+        // TODO: Hide if ignore-listed but consider what happens if every frame is ignore listed.
+        sourceMappedStack += '\n' + frameToString(sourcemappedFrame.stack)
+      }
+    }
+  }
+
+  return (
+    errorName +
+    ': ' +
+    error.message +
+    sourceMappedStack +
+    (sourceFrameDEV !== null ? '\n' + sourceFrameDEV : '')
+  )
+}
+
+export function patchErrorInspect() {
+  Error.prepareStackTrace = prepareUnsourcemappedStackTrace
+
+  // @ts-expect-error -- TODO upstream types
+  // eslint-disable-next-line no-extend-native -- We're not extending but overriding.
+  Error.prototype[inspectSymbol] = function (
+    depth: number,
+    inspectOptions: util.InspectOptions,
+    inspect: typeof util.inspect
+  ): string {
+    // Create a new Error object with the source mapping applied and then use native
+    // Node.js formatting on the result.
+    const newError =
+      this.cause !== undefined
+        ? // Setting an undefined `cause` would print `[cause]: undefined`
+          new Error(this.message, { cause: this.cause })
+        : new Error(this.message)
+
+    // TODO: Ensure `class MyError extends Error {}` prints `MyError` as the name
+    newError.stack = parseAndSourceMap(this)
+
+    for (const key in this) {
+      if (!Object.prototype.hasOwnProperty.call(newError, key)) {
+        // @ts-expect-error -- We're copying all enumerable properties.
+        // So they definitely exist on `this` and obviously have no type on `newError` (yet)
+        newError[key] = this[key]
+      }
+    }
+
+    const originalCustomInspect = (newError as any)[inspectSymbol]
+    // Prevent infinite recursion.
+    // { customInspect: false } would result in `error.cause` not using our inspect.
+    Object.defineProperty(newError, inspectSymbol, {
+      value: undefined,
+      enumerable: false,
+      writable: true,
+    })
+    try {
+      return inspect(newError, {
+        ...inspectOptions,
+        depth:
+          (inspectOptions.depth ??
+            // Default in Node.js
+            2) - depth,
+      })
+    } finally {
+      ;(newError as any)[inspectSymbol] = originalCustomInspect
+    }
+  }
+}

test/e2e/app-dir/actions/app-action-size-limit-invalid.test.ts

@@ -1,5 +1,6 @@
 import { nextTestSetup } from 'e2e-utils'
 import { retry } from 'next-test-utils'
+import stripAnsi from 'strip-ansi'
 import { accountForOverhead } from './account-for-overhead'
 
 const CONFIG_ERROR =
@@ -26,7 +27,7 @@ describe('app-dir action size limit invalid config', () => {
 
   beforeAll(() => {
     const onLog = (log: string) => {
-      logs.push(log.trim())
+      logs.push(stripAnsi(log.trim()))
     }
 
     next.on('stdout', onLog)
@@ -115,7 +116,7 @@ describe('app-dir action size limit invalid config', () => {
 
       await retry(() => {
         expect(logs).toContainEqual(
-          expect.stringContaining('[Error]: Body exceeded 1.5mb limit')
+          expect.stringContaining('Error: Body exceeded 1.5mb limit')
         )
         expect(logs).toContainEqual(
           expect.stringContaining(

test/e2e/app-dir/dynamic-io-errors/dynamic-io-errors.prospective-fallback.test.ts

@@ -27,6 +27,7 @@ describe(`Dynamic IO Prospective Fallback`, () => {
         // we expect the build to fail
       }
 
+      // TODO: Assert on component stack
       expect(next.cliOutput).toContain(
         'In Route "/blog/[slug]" this component accessed data without a Suspense boundary above it to provide a fallback UI.'
       )

test/e2e/app-dir/dynamic-io-errors/fixtures/prospective-fallback/next.config.js

@@ -1,5 +1,6 @@
 module.exports = {
   experimental: {
     dynamicIO: true,
+    serverSourceMaps: true,
   },
 }

test/e2e/app-dir/server-source-maps/fixtures/default/app/layout.js

@@ -0,0 +1,7 @@
+export default function Root({ children }) {
+  return (
+    <html>
+      <body>{children}</body>
+    </html>
+  )
+}

test/e2e/app-dir/server-source-maps/fixtures/default/app/rsc-error-log-cause/page.js

@@ -0,0 +1,12 @@
+export const dynamic = 'force-dynamic'
+
+function logError(cause) {
+  const error = new Error('Boom', { cause })
+  console.error(error)
+}
+
+export default function Page() {
+  const error = new Error('Boom')
+  logError(error)
+  return null
+}

test/e2e/app-dir/server-source-maps/fixtures/default/app/rsc-error-log-custom-name/page.js

@@ -0,0 +1,12 @@
+export const dynamic = 'force-dynamic'
+
+class UnnamedError extends Error {}
+class NamedError extends Error {
+  name = 'MyError'
+}
+
+export default function Page() {
+  console.error(new UnnamedError('Foo'))
+  console.error(new NamedError('Bar'))
+  return null
+}

test/e2e/app-dir/server-source-maps/fixtures/default/app/rsc-error-log/page.js

@@ -0,0 +1,11 @@
+export const dynamic = 'force-dynamic'
+
+function logError() {
+  const error = new Error('Boom')
+  console.error(error)
+}
+
+export default function Page() {
+  logError()
+  return null
+}

test/e2e/app-dir/server-source-maps/fixtures/default/next.config.js

@@ -0,0 +1,10 @@
+/**
+ * @type {import('next').NextConfig}
+ */
+const nextConfig = {
+  experimental: {
+    serverSourceMaps: true,
+  },
+}
+
+module.exports = nextConfig

test/e2e/app-dir/server-source-maps/server-source-maps.test.ts

@@ -0,0 +1,34 @@
+import * as path from 'path'
+import { nextTestSetup } from 'e2e-utils'
+
+describe('app-dir - server source maps', () => {
+  const { skipped, next, isNextDev } = nextTestSetup({
+    files: path.join(__dirname, 'fixtures/default'),
+    // Deploy tests don't have access to runtime logs.
+    // Manually verify that the runtime logs match.
+    skipDeployment: true,
+  })
+
+  if (skipped) return
+
+  it('logged errors have a sourcemapped stack with a codeframe', async () => {
+    // TODO: Write test once we run with `--enable-source-maps` when `experimental.serverSourceMaps` is set
+  })
+
+  it('logged errors have a sourcemapped `cause`', async () => {
+    // TODO: Write test once we run with `--enable-source-maps` when `experimental.serverSourceMaps` is set
+  })
+
+  it('logged errors preserve their name', async () => {
+    await next.render('/rsc-error-log-custom-name')
+
+    expect(next.cliOutput).toContain(
+      // TODO: isNextDev ? 'UnnamedError: Foo' : '[Error]: Foo'
+      isNextDev ? 'Error: Foo' : 'Error: Foo'
+    )
+    expect(next.cliOutput).toContain(
+      // TODO: isNextDev ? 'NamedError [MyError]: Bar' : '[MyError]: Bar'
+      isNextDev ? 'Error [MyError]: Bar' : 'Error [MyError]: Bar'
+    )
+  })
+})