read-transform-write

An easy-to-use utility to transform files with a single function. It uses fs.readFile and fs.writeFile under the hood and throws an error if something goes wrong. The encoding is set to utf8. If you need something else, please file an issue.

Support Me

If you're using Robin Frischmann's work, please consider supporting his Open Source Projects on Patreon.

Installation

# yarn
yarn add read-transform-write

# npm
npm i --save read-transform-write

Usage

Parameter

| Parameter | Type | Description | | --- | --- | --- | | inputPath | (string) | The absolute path to the input file. | | transform | (Function) | The transformation method.It receives the input data and returns method receving a write-method that must be called with the transformed data and a output path. | | callback | (Function?) | An optional callback that receives an object with the callback shape. |

Callback Shape

type Callback {
  inputPath: string,
  outputPath: string,
  input: string,
  output: string
}

Example

import { join } from 'path'
import transformFile from 'read-transform-write'

const input = join(__dirname, 'input.txt')
const output = join(__dirname, 'output.txt')

const transform = data => write => write(
  output,
  data
    .split('\n')
    .map(val => parseInt(val, 10))
    .map(Math.sqrt)
    .join('\n')
)

transformFile(
  input,
  transform,
  ({ output, outputPath }) => {
    console.log(`Written ${output} to ${outputPath}.`)
  }
)

input.txt

49
36
25
16

output.txt

7
6
5
4

License

read-transform-write is licensed under the MIT License. Documentation is licensed under Creative Common License. Created with ♥ by @rofrischmann.