stream-assert

stream-assert

Assert streams with ease.

Usage

var array = require('stream-array');
var assert = require('stream-assert');
var should = require('should');

array([1, 2, 3])
    .pipe(assert.first(function(data) { data.should.eql(1); }))
    .pipe(assert.second(function(data) { data.should.eql(2); }))
    .pipe(assert.nth(2, function(data) { data.should.eql(3); }))
    .pipe(assert.length(1))
    .pipe(assert.end(console.log)) // One way
    .on('end', console.log) // Or another

API

stream-assert

Builder for asserting stream. Constructed stream will emit end on wrong assertion about stream with assertion error as first argument.

nth(n, assertion)

Calls assertion function on nth element in stream.

first(assertion)

alias to nth(0, obj)

second(assertion)

alias to nth(1, obj)

last(assertion)

Calls assertion function on the last element in stream.

length(len)

Asserting, that length of stream is equal len at the end of the stream.

all(assertion)

Checking that all elements in stream pass assertion function.

any(assertion)

Checking that at least one of elements in stream pass assertion function.

end([cb])

Since streams has internal buffer and highWatermark, that stops data flow, when reached — test stream needs a dumping point, that will flush that buffer.

assert.end will dump all data to /dev/null — so all pipes after this point will not get any data.

assert.defaults

Type: Object

Contains defaults, that will be passed to through constructor.

• highWatermark — by default, will be equal 16. If you don't want to use assert.end, then you can increase it.

License

MIT (c) 2014 Vsevolod Strukchinsky