Method patchFile

test/lib/next-modes/base.ts:745–778

(
    filename: string,
    content: string | ((content: string | undefined) => string),
    runWithTempContent?: (context: { newFile: boolean }) => Promise<void>
  )

  }

  public async patchFile(
    filename: string,
    content: string | ((content: string | undefined) => string),
    runWithTempContent?: (context: { newFile: boolean }) => Promise<void>
  ): Promise<{ newFile: boolean }> {
    const outputPath = path.join(this.testDir, filename)
    const newFile = !existsSync(outputPath)
    await fs.mkdir(path.dirname(outputPath), { recursive: true })
    const previousContent = newFile ? undefined : await this.readFile(filename)

    await fs.writeFile(
      outputPath,
      typeof content === 'function' ? content(previousContent) : content,
      {
        flush: true,
      }
    )

    if (runWithTempContent) {
      try {
        await runWithTempContent({ newFile })
      } finally {
        if (previousContent === undefined) {
          await fs.rm(outputPath)
        } else {
          await fs.writeFile(outputPath, previousContent, {
            flush: true,
          })
        }
      }
    }

    return { newFile }
  }

  public async renameFile(filename: string, newFilename: string) {
    await fs.rename(