next.js/packages/next/src/server/app-render/create-error-handler.tsx

import type { ErrorInfo } from 'react'

import stringHash from 'next/dist/compiled/string-hash'
import { formatServerError } from '../../lib/format-server-error'
import { SpanStatusCode, getTracer } from '../lib/trace/tracer'
import { isAbortError } from '../pipe-readable'
import { isBailoutToCSRError } from '../../shared/lib/lazy-dynamic/bailout-to-csr'
import { isDynamicServerError } from '../../client/components/hooks-server-context'
import { isNextRouterError } from '../../client/components/is-next-router-error'
import { isPrerenderInterruptedError } from './dynamic-rendering'
import { getProperError } from '../../lib/is-error'
import { createDigestWithErrorCode } from '../../lib/error-telemetry-utils'
import { isReactLargeShellError } from './react-large-shell-error'

declare global {
  var __next_log_error__: undefined | ((err: unknown) => void)
}

type RSCErrorHandler = (err: unknown) => string | undefined
type SSRErrorHandler = (
  err: unknown,
  errorInfo?: ErrorInfo
) => string | undefined

export type DigestedError = Error & { digest: string }

/**
 * Returns a digest for well-known Next.js errors, otherwise `undefined`. If a
 * digest is returned this also means that the error does not need to be
 * reported.
 */
export function getDigestForWellKnownError(error: unknown): string | undefined {
  // If we're bailing out to CSR, we don't need to log the error.
  if (isBailoutToCSRError(error)) return error.digest

  // If this is a navigation error, we don't need to log the error.
  if (isNextRouterError(error)) return error.digest

  // If this error occurs, we know that we should be stopping the static
  // render. This is only thrown in static generation when PPR is not enabled,
  // which causes the whole page to be marked as dynamic. We don't need to
  // tell the user about this error, as it's not actionable.
  if (isDynamicServerError(error)) return error.digest

  // If this is a prerender interrupted error, we don't need to log the error.
  if (isPrerenderInterruptedError(error)) return error.digest

  return undefined
}

export function createFlightReactServerErrorHandler(
  shouldFormatError: boolean,
  onReactServerRenderError: (err: DigestedError) => void
): RSCErrorHandler {
  return (thrownValue: unknown) => {
    if (typeof thrownValue === 'string') {
      // TODO-APP: look at using webcrypto instead. Requires a promise to be awaited.
      return stringHash(thrownValue).toString()
    }

    // If the response was closed, we don't need to log the error.
    if (isAbortError(thrownValue)) return

    const digest = getDigestForWellKnownError(thrownValue)

    if (digest) {
      return digest
    }

    if (isReactLargeShellError(thrownValue)) {
      // TODO: Aggregate
      console.error(thrownValue)
      return undefined
    }

    const err = getProperError(thrownValue) as DigestedError

    // If the error already has a digest, respect the original digest,
    // so it won't get re-generated into another new error.
    if (!err.digest) {
      // TODO-APP: look at using webcrypto instead. Requires a promise to be awaited.
      err.digest = stringHash(err.message + err.stack || '').toString()
    }

    // Format server errors in development to add more helpful error messages
    if (shouldFormatError) {
      formatServerError(err)
    }

    // Record exception in an active span, if available.
    const span = getTracer().getActiveScopeSpan()
    if (span) {
      span.recordException(err)
      span.setStatus({
        code: SpanStatusCode.ERROR,
        message: err.message,
      })
    }

    onReactServerRenderError(err)

    return createDigestWithErrorCode(thrownValue, err.digest)
  }
}

export function createHTMLReactServerErrorHandler(
  shouldFormatError: boolean,
  isNextExport: boolean,
  reactServerErrors: Map<string, DigestedError>,
  silenceLogger: boolean,
  onReactServerRenderError: undefined | ((err: DigestedError) => void)
): RSCErrorHandler {
  return (thrownValue: unknown) => {
    if (typeof thrownValue === 'string') {
      // TODO-APP: look at using webcrypto instead. Requires a promise to be awaited.
      return stringHash(thrownValue).toString()
    }

    // If the response was closed, we don't need to log the error.
    if (isAbortError(thrownValue)) return

    const digest = getDigestForWellKnownError(thrownValue)

    if (digest) {
      return digest
    }

    if (isReactLargeShellError(thrownValue)) {
      // TODO: Aggregate
      console.error(thrownValue)
      return undefined
    }

    const err = getProperError(thrownValue) as DigestedError

    // If the error already has a digest, respect the original digest,
    // so it won't get re-generated into another new error.
    if (!err.digest) {
      // TODO-APP: look at using webcrypto instead. Requires a promise to be awaited.
      err.digest = stringHash(err.message + (err.stack || '')).toString()
    }

    // @TODO by putting this here and not at the top it is possible that
    // we don't error the build in places we actually expect to
    if (!reactServerErrors.has(err.digest)) {
      reactServerErrors.set(err.digest, err)
    }

    // Format server errors in development to add more helpful error messages
    if (shouldFormatError) {
      formatServerError(err)
    }

    // Don't log the suppressed error during export
    if (
      !(
        isNextExport &&
        err?.message?.includes(
          'The specific message is omitted in production builds to avoid leaking sensitive details.'
        )
      )
    ) {
      // Record exception in an active span, if available.
      const span = getTracer().getActiveScopeSpan()
      if (span) {
        span.recordException(err)
        span.setStatus({
          code: SpanStatusCode.ERROR,
          message: err.message,
        })
      }

      if (!silenceLogger) {
        onReactServerRenderError?.(err)
      }
    }

    return createDigestWithErrorCode(thrownValue, err.digest)
  }
}

export function createHTMLErrorHandler(
  shouldFormatError: boolean,
  isNextExport: boolean,
  reactServerErrors: Map<string, DigestedError>,
  allCapturedErrors: Array<unknown>,
  silenceLogger: boolean,
  onHTMLRenderSSRError: (err: DigestedError, errorInfo?: ErrorInfo) => void
): SSRErrorHandler {
  return (thrownValue: unknown, errorInfo?: ErrorInfo) => {
    if (isReactLargeShellError(thrownValue)) {
      // TODO: Aggregate
      console.error(thrownValue)
      return undefined
    }

    let isSSRError = true

    allCapturedErrors.push(thrownValue)

    // If the response was closed, we don't need to log the error.
    if (isAbortError(thrownValue)) return

    const digest = getDigestForWellKnownError(thrownValue)

    if (digest) {
      return digest
    }

    const err = getProperError(thrownValue) as DigestedError
    // If the error already has a digest, respect the original digest,
    // so it won't get re-generated into another new error.
    if (err.digest) {
      if (reactServerErrors.has(err.digest)) {
        // This error is likely an obfuscated error from react-server.
        // We recover the original error here.
        thrownValue = reactServerErrors.get(err.digest)
        isSSRError = false
      } else {
        // The error is not from react-server but has a digest
        // from other means so we don't need to produce a new one
      }
    } else {
      err.digest = stringHash(
        err.message + (errorInfo?.componentStack || err.stack || '')
      ).toString()
    }

    // Format server errors in development to add more helpful error messages
    if (shouldFormatError) {
      formatServerError(err)
    }

    // Don't log the suppressed error during export
    if (
      !(
        isNextExport &&
        err?.message?.includes(
          'The specific message is omitted in production builds to avoid leaking sensitive details.'
        )
      )
    ) {
      // Record exception in an active span, if available.
      const span = getTracer().getActiveScopeSpan()
      if (span) {
        span.recordException(err)
        span.setStatus({
          code: SpanStatusCode.ERROR,
          message: err.message,
        })
      }

      if (
        !silenceLogger &&
        // HTML errors contain RSC errors as well, filter them out before reporting
        isSSRError
      ) {
        onHTMLRenderSSRError(err, errorInfo)
      }
    }

    return createDigestWithErrorCode(thrownValue, err.digest)
  }
}

export function isUserLandError(err: any): boolean {
  return (
    !isAbortError(err) && !isBailoutToCSRError(err) && !isNextRouterError(err)
  )
}