mutate-stream

mutate-stream

Object mutation pipelines for flow control

I think object mode streams are really handy for async flow control:

var stream = require('mutate-stream');

validate(req.body)
  .pipe(sanitize())
  .pipe(whatever())
  .pipe(dbWrite)

This module is a simple wrapper to eliminate boilerplate in a lot of my applications.

Installation

Download node at nodejs.org and install it, if you haven't already.

npm install mutate-stream --save

Usage

stream(<transform function>, [ optional flush function ]);

Pass in a transform function and an optional flush function. mutate-stream returns a a function that can take an optional data object parameter (to start your pipeline). This function in turn returns a stream.

Example:

var stream = require('mutate-stream');

function foo (obj, encoding, cb) { /* some transform */ }
function bar (obj, encoding, cb) { /* some transform */ }

var fooStream = stream(foo),
    barStream = stream(bar);

fooStream({some: 'optional data'})
  .pipe(barStream());

Tests

npm install
npm test

> mutate-stream@0.0.0 test /Users/mark/projects/mutate-stream
> node test/mutate-stream.js
TAP version 13
# wraps transform function
ok 1 should be equivalent
1..1
# tests 1
# pass  1
# ok

Dependencies

• through2: A tiny wrapper around Node streams2 Transform to avoid explicit subclassing noise

Dev Dependencies

• stream-output: Get the result of a streams transform pipeline for your tests
• tape: tap-producing test harness for node and browsers

License

MIT