value2stream

value2stream

Transform any value to stream. Create a stream from any value - string, array, buffer, number, promise or even Error object.

Note: Be aware of that if you pass Error object you will still recieve it as value. It won't fire the error event on created stream. That will only happen if you pass rejected promise. And all this is intentional - you just pass a value and recieve a stream with that value.

Install

npm i value2stream --save

Usage

For more use-cases see the tests

const value2stream = require('value2stream')

value2stream

Create a stream from any value.

Params

• val {Mixed}: Any type of value except function. Use callback2stream for functions.
• [opts] {Object|Function=}: Directly passed to promise2stream and through2, otherwise Promise contstructor.
• [Promize] {Function}: Promise constructor to be used when no support for native Promise.
• returns {Stream}

Example

var toStream = require('value2promise')

toStream(123).on('data', function (val) {
  console.log(val) // => 123
})
toStream('str foo').on('data', function (val) {
  console.log(val) // => 'str foo'
})

// not throws if `opts.objectMode: true` (default)
toStream({ foo: 'bar' }).on('data', function (val) {
  console.log(val) // => { foo: 'bar' }
})

// throws when non-object mode
toStream({ foo: 'bar' }, { objectMode: false })
  .once('error', function (err) {
    console.log(err instanceof Error) // => true
    console.log(err) // => [Error: Invalid non-string/buffer chunk]
  })

// same applies if non-object and promise resolves object
var fails = Promise.resolve({ a: 'b' })
toStream(fails, { objectMode: false })
  .once('error', function (err) {
    console.log(err instanceof Error) // => true
    console.log(err) // => [Error: Invalid non-string/buffer chunk]
  })

var promise = Promise.resolve('foo bar')
toStream(promise).on('data', function (val) {
  console.log(val) // => 'foo bar'
})

var rejected = Promise.reject(new Error('err msg'))
toStream(rejected).once('error', function (err) {
  console.log(err instanceof Error) // => true
  console.log(err.message) // => 'err msg'
})

Related

• callback2stream: Transform sync, async or generator function to Stream. Correctly handle… more | homepage
• native-promise: Get native Promise or falsey value if not available. | homepage
• to-stream: Turn an array to a Node.js stream | homepage
• promise2stream: Transform ES2015 Promise to Stream - specifically, Transform Stream using… more | homepage
• promise2thunk: Convert (transform) promise to thunk, just like was in co@3 | homepage
• relike: Simple promisify a callback-style function with sane defaults. Support promisify-ing… more | homepage
• thunk2promise: Transform or convert thunk to Bluebird Promise. | homepage

Contributing

Pull requests and stars are always welcome. For bugs and feature requests, please create an issue.
But before doing anything, please read the CONTRIBUTING.md guidelines.

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