askirmas / postcss-d-ts

import {createReadStream} from 'fs'

import {createInterface} from 'readline'

import {

  $close,

  $exists,

  $open,

  $rename,

  $copy,

  $write,

  $unlink,

  tempFileName,

} from "./fs"

export = rewrite

async function rewrite(filename: string, lines: string[], eol: string, checkMode: boolean) {

  const {length} = lines

  , fileExists = await $exists(filename)

  let line: string = "undefined"

  , row = 0

  if (fileExists) {

    const lineReader = createInterface({

      input: createReadStream(filename),

      crlfDelay: Infinity,

      historySize: 0

    })

    let isSame = true

    for await (line of lineReader) {

      if (line !== lines[row]) {

        isSame = false

        break

      }

      row++

    }

    lineReader.close()

    if (isSame) {

      if (lines[row] === "")

        row++

      if (length === row)

        return

    }

  }

  if (checkMode)

    throw new Error([

      `Content of "${filename}:${row + 1}" should be another`,

      "- Expected:",

      lines[row],

      "+ Received:",

      line

    ].join("\n"))

  const tempFile = await tempFileName()

  , fd = await $open(tempFile, "w")

  for (let i = 0; i < length; i++)

    await $write(fd, `${

      i ? eol : ''

    }${

      lines[i]

    }`)

  await $close(fd)

  try {

    await $rename(tempFile, filename)

  } catch (error) {

    /* istanbul ignore next https://github.com/askirmas/postcss-d-ts/pull/30 */

    await $copy(tempFile, filename)

    /* istanbul ignore next https://github.com/askirmas/postcss-d-ts/pull/30 */

    await $unlink(tempFile)

  }

}