https://github.com/mcollina/streampecker

Peek a stream!
https://github.com/mcollina/streampecker

Last synced: about 1 month ago
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Peek a stream!

• Host: GitHub
• URL: https://github.com/mcollina/streampecker
• Owner: mcollina
• License: mit
• Created: 2022-06-29T10:09:59.000Z (over 2 years ago)
• Default Branch: main
• Last Pushed: 2022-06-29T22:30:15.000Z (over 2 years ago)
• Last Synced: 2024-11-01T12:42:21.498Z (about 2 months ago)
• Language: JavaScript
• Size: 15.6 KB
• Stars: 14
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# streampecker

Transform stream that lets you peek the first line before deciding how to parse it.

```

npm install streampecker

```

This module was forked from [`peak-stream`](https://github.com/mafintosh/peak-stream) at version v1.1.3.

## Usage

```js

const pecker = require('streampecker')

const ldjson = require('ldjson-stream')

const csv = require('csv-parser')

const { Readable } = require('stream')

const isCSV = function (data) {

  return data.toString().indexOf(',') > -1

}

const isJSON = function (data) {

  try {

    JSON.parse(data)

    return true

  } catch (err) {

    return false

  }

}

const parser = function (stream) {

  return pecker(stream, function (data) {

    // maybe it is JSON?

    if (isJSON(data)) return ldjson()

    // maybe it is CSV?

    if (isCSV(data)) return csv()

    // we do not know - bail

    throw new Error('No parser available')

  })

}

let parse

parse = parser(Readable.from('{"hello":"world"}\n{"hello":"another"}\n'))

parse.on('data', function (data) {

  console.log('from ldj:', data)

})

parse = parser(Readable.from('test,header\nvalue-1,value-2\n'))

parse.on('data', function (data) {

  console.log('from csv:', data)

})

```

## License

MIT