Function nativeTraceSource

packages/next/src/server/dev/middleware-turbopack.ts:180–283

* @returns 1-based lines and 1-based columns

(
  frame: TurbopackStackFrame
)

 * @returns 1-based lines and 1-based columns
 */
async function nativeTraceSource(
  frame: TurbopackStackFrame
): Promise<{ frame: IgnorableStackFrame; source: string | null } | undefined> {
  const sourceURL = frame.file
  let sourceMapPayload: ModernSourceMapPayload | undefined
  try {
    sourceMapPayload = findSourceMap(sourceURL)?.payload
  } catch (cause) {
    throw new Error(
      `${sourceURL}: Invalid source map. Only conformant source maps can be used to find the original code.`,
      { cause }
    )
  }

  if (sourceMapPayload !== undefined) {
    let consumer: SourceMapConsumer
    try {
      consumer = await new SourceMapConsumer(sourceMapPayload)
    } catch (cause) {
      throw new Error(
        `${sourceURL}: Invalid source map. Only conformant source maps can be used to find the original code.`,
        { cause }
      )
    }
    let traced: {
      originalPosition: NullableMappedPosition
      sourceContent: string | null
    } | null
    try {
      const originalPosition = consumer.originalPositionFor({
        line: frame.line ?? 1,
        // 0-based columns out requires 0-based columns in.
        column: (frame.column ?? 1) - 1,
      })

      if (originalPosition.source === null) {
        traced = null
      } else {
        const sourceContent: string | null =
          consumer.sourceContentFor(
            originalPosition.source,
            /* returnNullOnMissing */ true
          ) ?? null

        traced = { originalPosition, sourceContent }
      }
    } finally {
      consumer.destroy()
    }

    if (traced !== null) {
      const { originalPosition, sourceContent } = traced
      const applicableSourceMap = findApplicableSourceMapPayload(
        (frame.line ?? 1) - 1,
        (frame.column ?? 1) - 1,
        sourceMapPayload
      )