next.js/packages/next/src/server/dev/browser-logs/source-map.ts

import { getOriginalStackFrames as getOriginalStackFramesWebpack } from '../middleware-webpack'
import { getOriginalStackFrames as getOriginalStackFramesTurbopack } from '../middleware-turbopack'
import type { Project } from '../../../build/swc/types'
import { dim } from '../../../lib/picocolors'
import { parseStack, type StackFrame } from '../../lib/parse-stack'
import path from 'path'
import { LRUCache } from '../../lib/lru-cache'

type WebpackMappingContext = {
  bundler: 'webpack'
  isServer: boolean
  isEdgeServer: boolean
  isAppDirectory: boolean
  clientStats: () => any
  serverStats: () => any
  edgeServerStats: () => any
  rootDirectory: string
}

type TurbopackMappingContext = {
  bundler: 'turbopack'
  isServer: boolean
  isEdgeServer: boolean
  isAppDirectory: boolean
  project: Project
  projectPath: string
}

export type MappingContext = WebpackMappingContext | TurbopackMappingContext

// TODO: handle server vs browser error source mapping correctly
export async function mapFramesUsingBundler(
  frames: StackFrame[],
  ctx: MappingContext
) {
  switch (ctx.bundler) {
    case 'webpack': {
      const {
        isServer,
        isEdgeServer,
        isAppDirectory,
        clientStats,
        serverStats,
        edgeServerStats,
        rootDirectory,
      } = ctx
      const res = await getOriginalStackFramesWebpack({
        isServer,
        isEdgeServer,
        isAppDirectory,
        frames,
        clientStats,
        serverStats,
        edgeServerStats,
        rootDirectory,
      })
      return res
    }
    case 'turbopack': {
      const { project, projectPath, isServer, isEdgeServer, isAppDirectory } =
        ctx
      const res = await getOriginalStackFramesTurbopack({
        project,
        projectPath,
        frames,
        isServer,
        isEdgeServer,
        isAppDirectory,
      })

      return res
    }
    default: {
      return null!
    }
  }
}

// converts _next/static/chunks/... to file:///.next/static/chunks/... for parseStack
// todo: where does next dev overlay handle this case and re-use that logic
function preprocessStackTrace(stackTrace: string, distDir?: string): string {
  return stackTrace
    .split('\n')
    .map((line) => {
      const match = line.match(/^(\s*at\s+.*?)\s+\(([^)]+)\)$/)
      if (match) {
        const [, prefix, location] = match

        if (location.startsWith('_next/static/') && distDir) {
          const normalizedDistDir = distDir
            .replace(/\\/g, '/')
            .replace(/\/$/, '')

          const absolutePath =
            normalizedDistDir + '/' + location.slice('_next/'.length)
          const fileUrl = `file://${path.resolve(absolutePath)}`

          return `${prefix} (${fileUrl})`
        }
      }

      return line
    })
    .join('\n')
}

const cache = new LRUCache<
  Awaited<ReturnType<typeof getSourceMappedStackFramesInternal>>
>(25)
async function getSourceMappedStackFramesInternal(
  stackTrace: string,
  ctx: MappingContext,
  distDir: string,
  ignore = true
) {
  try {
    const normalizedStack = preprocessStackTrace(stackTrace, distDir)
    const frames = parseStack(normalizedStack, distDir)

    if (frames.length === 0) {
      return {
        kind: 'stack' as const,
        stack: stackTrace,
      }
    }

    const mappingResults = await mapFramesUsingBundler(frames, ctx)

    const processedFrames = mappingResults
      .map((result, index) => ({
        result,
        originalFrame: frames[index],
      }))
      .map(({ result, originalFrame }) => {
        if (result.status === 'rejected') {
          return {
            kind: 'rejected' as const,
            frameText: formatStackFrame(originalFrame),
            codeFrame: null,
          }
        }

        const { originalStackFrame, originalCodeFrame } = result.value
        if (originalStackFrame?.ignored && ignore) {
          return {
            kind: 'ignored' as const,
          }
        }

        // should we apply this generally to dev overlay (dev overlay does not ignore chrome-extension://)
        if (originalStackFrame?.file?.startsWith('chrome-extension://')) {
          return {
            kind: 'ignored' as const,
          }
        }

        return {
          kind: 'success' as const,
          // invariant: if result is not rejected and not ignored, then original stack frame exists
          // verifiable by tracing `getOriginalStackFrame`. The invariant exists because of bad types
          frameText: formatStackFrame(originalStackFrame!),
          codeFrame: originalCodeFrame,
        }
      })

    const allIgnored = processedFrames.every(
      (frame) => frame.kind === 'ignored'
    )

    // we want to handle **all** ignored vs all/some rejected differently
    // if all are ignored we should show no frames
    // if all are rejected, we want to fallback to showing original stack frames
    if (allIgnored) {
      return {
        kind: 'all-ignored' as const,
      }
    }

    const filteredFrames = processedFrames.filter(
      (frame) => frame.kind !== 'ignored'
    )

    if (filteredFrames.length === 0) {
      return {
        kind: 'stack' as const,
        stack: stackTrace,
      }
    }

    const stackOutput = filteredFrames
      .map((frame) => frame.frameText)
      .join('\n')
    const firstFrameCode = filteredFrames.find(
      (frame) => frame.codeFrame
    )?.codeFrame

    if (firstFrameCode) {
      return {
        kind: 'with-frame-code' as const,
        frameCode: firstFrameCode,
        stack: stackOutput,
        frames: filteredFrames,
      }
    }
    // i don't think this a real case, but good for exhaustion
    return {
      kind: 'mapped-stack' as const,
      stack: stackOutput,
      frames: filteredFrames,
    }
  } catch (error) {
    return {
      kind: 'stack' as const,
      stack: stackTrace,
    }
  }
}

// todo: cache the actual async call, not the wrapper with post processing
export async function getSourceMappedStackFrames(
  stackTrace: string,
  ctx: MappingContext,
  distDir: string,
  ignore = true
) {
  const cacheKey = `sm_${stackTrace}-${ctx.bundler}-${ctx.isAppDirectory}-${ctx.isEdgeServer}-${ctx.isServer}-${distDir}-${ignore}`

  const cacheItem = cache.get(cacheKey)
  if (cacheItem) {
    return cacheItem
  }

  const result = await getSourceMappedStackFramesInternal(
    stackTrace,
    ctx,
    distDir,
    ignore
  )
  cache.set(cacheKey, result)
  return result
}

function formatStackFrame(frame: StackFrame): string {
  const functionName = frame.methodName || '<anonymous>'
  const location =
    frame.file && frame.line1
      ? `${frame.file}:${frame.line1}${frame.column1 ? `:${frame.column1}` : ''}`
      : frame.file || '<unknown>'

  return `    at ${functionName} (${location})`
}

// appends the source mapped location of the console method
export const withLocation = async (
  {
    original,
    stack,
  }: {
    original: Array<any>
    stack: string | null
  },
  ctx: MappingContext,
  distDir: string,
  config: boolean | { logDepth?: number; showSourceLocation?: boolean }
) => {
  if (typeof config === 'object' && config.showSourceLocation === false) {
    return original
  }
  if (!stack) {
    return original
  }

  const res = await getSourceMappedStackFrames(stack, ctx, distDir)
  const location = getConsoleLocation(res)

  if (!location) {
    return original
  }

  return [...original, dim(`(${location})`)]
}

export const getConsoleLocation = (
  mapped: Awaited<ReturnType<typeof getSourceMappedStackFrames>>
) => {
  if (mapped.kind !== 'mapped-stack' && mapped.kind !== 'with-frame-code') {
    return null
  }

  const first = mapped.frames.at(0)

  if (!first) {
    return null
  }

  // we don't want to show the name of parent function (at <fn> thing in stack), just source location for minimal noise
  const match = first.frameText.match(/\(([^)]+)\)/)
  const locationText = match ? match[1] : first.frameText
  return locationText
}