如何使用 FP-TS 改进此打字稿代码？

Question

我正在尝试使用 fp-ts 编写一些打字稿代码

算法应执行的任务如下：

从命令行接收路径应该

验证路径是否存在
搜索目录中的所有文件和 select 一个包含名称 cratb.import 和扩展名“.json”的文件 | “.yaml” | “.yml”
if is ".json" 使用 js-yaml 包将纯文本解析为对象 JSON.parse else if is ".yaml" 将纯文本解析为对象 YAML.load

这是我的主要代码：

if(FpFs.pathExists(targetPath)){
  const res = await pipe(
    FpFs.readDir(targetPath),
    TE.map((files) =>
      O.fromNullable(files.find(e => e === `${dFileName}.yaml` || e === `${dFileName}.yml` || e === `${dFileName}.json`))
    ),
    TE.map(
      O.map(fileName =>
        ['json', 'JSON', 'yaml', 'YAML', 'yml', 'YML'].includes(getFileExtension(fileName))
          ? O.fromNullable(fileName)
          : O.fromNullable(null)
      )
    ),
    TE.map(O.flatten),
    TE.map(
      O.map(
        fileName =>
          ['json', 'JSON'].includes(getFileExtension(fileName))
            ? pipe(
                FpFs.readFile(path.join(targetPath, fileName)),
                TE.map(x => JSON.parse(x.toString()))
              )
            : pipe(
              FpFs.readFile(path.join(targetPath, fileName)),
              TE.map(x => YAML.load(x.toString()))
            )
      )
    )
  )()
  if(E.isRight(res)){
    if(O.isSome(res.right)){
      res.right.value()
      .then(res => {
        if(E.isRight(res)){
          return console.log(res.right)
        }
      })
    }
  }
  console.log('Error in some point XD')
}else{
  console.log(color.red(['ERROR']), `directory "${ importFilePath }" not found`)
}

但我觉得这可能会更好

任何想法都会有所帮助

谢谢

Answer 1

经过更多的研究和 de community 的帮助，我想到了这个

helpers.ts

import * as O from 'fp-ts/lib/Option'

export const appendStrBefore = (appending: string) => (appended: string) => `${appending}${appended}`

export const isOneOfOptions = 
  (...options: string[]) =>
  (searched: string) =>
  options.includes(searched)

export const candidatesContainingSomeOfOptions =
  (options: string[]) =>
  (candidates: string[]): O.Option<string> => {
    const result = options.reduce((prev, curr) => prev === '' ? candidates.includes(curr) ? curr : prev : prev, '')
    return result === '' ? O.none : O.some(result)
  }

export const getFileExtension = (fileName: string): string => {
  const lastPeriod = fileName.lastIndexOf('.')
  return fileName.substring(lastPeriod + 1, fileName.length)
}

主文件

(importFilePath = '', { test }) => {    
const targetPath = path.join(process.cwd(), importFilePath)
const dFileName = 'cratb.import'
const extOptions = ['json', 'JSON', 'yaml', 'YAML', 'yml', 'YML']
const readFileAndParse =
  (path: string) =>
  (parser: Function) =>
  pipe(
    FpFs.readFile(path),
    TE.map(x => parser(x.toString()))
  )

FpFs.pathExists(targetPath)
  ? pipe(
    FpFs.readDir(targetPath),
    TE.map(
      files => pipe(
        extOptions.map(appendStrBefore(`${dFileName}.`)),
        (candidates) => candidatesContainingSomeOfOptions(candidates)(files)
      )
    ),
    TE.map(
      fileNameOption => 
      O.isSome(fileNameOption)
        ? pipe(
          readFileAndParse(path.join(targetPath, fileNameOption.value)),
          parsing => parsing(
            isOneOfOptions('json', 'JSON')(getFileExtension(fileNameOption.value)) //choose a parser
              ? JSON.parse
              : YAML.load
          ),
        )
        : TE.of('File not found')
    ),
    TE.fold(
      err => T.of(handleFSError(err)),
      TE.fold(
        err => T.of(handleFSError(err)),
        T.of
      )
    )
  )().then(parseConfigObject)
  : console.log(color.red(['ERROR']), `directory "${ importFilePath }" not found`)

现在我觉得更好

如何使用 FP-TS 改进此打字稿代码？

How can I improve this typescript code using FP-TS?

typescript

fp-ts