csegura/SeparatorTransform

SeparatorTransform

StreamTransform is a stream reader that divide the entry in delimited parts, without buffering the files into memory.

Install

npm install SeparatorTransform

Usage:

Synchronous processing of lines:

The module include two class a low level SeparatorTransform that do the work and another that simplify the use StreamSeparator

example Divide reader entry line by line

const reader = fs.createReadStream(fileName); // reader entry
const separator = new StreamSeparator({
  separator: /\r\n/g,
  omitChars: /\r\n/g,
});

await separator.read(
  reader,
  data => {
    // do something with data
    console.log(data);
  },
  () => {
    console.log("done");
  }
);

Usage:

Class: StreamSeparator({options})

options is an object with the following defaults:

{
  skipEmptyLines: true,
  separator: /\r\n/g,
  omits: /\|\r\n*$/,
}

read(reader, onChunk, onFinish)

readrer the entry stream onChunk function to process chunk of data onFinish function on finish

retruns a promise fulfilled when finish

Class: SeparatorTransform({options})

options same that StreamSeparator

use as any transfrom stream

const trasform = new SeparatorTransform({
  skipEmptyLines: true,
  separator: /,\r\n/g, // divide entry in lines and , separator
  omits: /\|,\r\n*$/, // remove that characters
});
input.pipe(transform).pipe(output);

License:

The MIT License (MIT)

© 2020 Carlos Segura