stream-assert

Assertion library for streams

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Readme

stream-assert
!Build Statustravis-imagetravis-url
Assert streams with ease.

Usage

var intoStream = require('into-stream');
var assert = require('stream-assert');
var is = require('funsert');

intoStream([1, 2, 3])
    .pipe(assert.first(is.equal(1)))
    .pipe(assert.second(is.equal(2)))
    .pipe(assert.nth(2, is.equal(3)))
    .pipe(assert.length(1))
    .pipe(assert.end(console.log));

Chaining

Assertions are chained through passing assertion from pipe to pipe. If you want inject assertions in the middle of pipeline, you can attach on('assertion') handler to manualy catch assertions (instead of placing assert.end).

API

stream-assert

Builder for asserting stream.

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