chai-immutable

Chai Immutable

This provide a set of Chai assertions for Facebook's Immutable library for JavaScript collections.

Installation

Install via npm:

npm install chai-immutable

You can then use this plugin as any other Chai plugins:

var chai = require('chai');
var chaiImmutable = require('chai-immutable');

chai.use(chaiImmutable);

API Reference

.empty

Asserts that the immutable collection is empty.

expect(List()).to.be.empty;
expect(List.of(1, 2, 3)).to.not.be.empty;

.equal(collection)

• @param { Collection } collection

Asserts that the values of the target are equvalent to the values of collection. Aliases of Chai's original equal method are also supported.

var a = List.of(1, 2, 3);
var b = List.of(1, 2, 3);
expect(a).to.equal(b);

.size(value)

• @param { Number } size

Asserts that the immutable collection's size property has the expected value.

expect(List.of(1, 2, 3)).to.have.size(3);

It can also be used as a chain precursor to a value comparison for the size property.

expect(List.of(1, 2, 3)).to.have.size.least(3);
expect(List.of(1, 2, 3)).to.have.size.most(3);
expect(List.of(1, 2, 3)).to.have.size.above(2);
expect(List.of(1, 2, 3)).to.have.size.below(4);
expect(List.of(1, 2, 3)).to.have.size.within(2,4);

Similarly to length/lengthOf, sizeOf can be used as an alias of size:

expect(List.of(1, 2, 3)).to.have.sizeOf(3);