Welcome to Unexpected

The extensible BDD assertion toolkit

expect({ text: 'f00!' }, 'to equal', { text: 'foo!' });

expected { text: 'f00!' } to equal { text: 'foo!' }

{

text:

'f00!'

should equal

'foo!'

f00!

foo!

}

Features

Extensible
Fast
Provides really nice error messages
Helps you if you misspells assertions
Compatible with all test frameworks.
Node.JS ready (require('unexpected')).
Single global with no prototype extensions or shims.
Cross-browser: works on Chrome, Firefox, Safari, Opera, IE6+, (IE6-IE8 with es5-shim).

Node

Install it with NPM or add it to your package.json:

$ npm install unexpected

Then:

var expect = require('unexpected');

Browser

Include unexpected.js.

this will expose the expect function under the following namespace:

var expect = weknowhow.expect;

RequireJS

Include the library with RequireJS the following way:

require.config({

paths: {

unexpected: 'path/to/unexpected'

}

});

define(['unexpected'], function (expect) {

// Your code

});

Using Unexpected with a test framework

For example, if you create a test suite with mocha.

Let's say we wanted to test the following program:

math.js

function add (a, b) { return a + b; };

Our test file would look like this:

describe('math.js', function () {

describe('add', function () {

it('is a function', function () {

expect(add, 'to be a', 'function');

});

it('does addition on numbers', function () {

expect(add(1, 3), 'to be', 4);

});

If a certain expectation fails, an exception will be raised which gets captured and shown/processed by the test runner.

Source

The source for Unexpected can be found on Github.

Releases

6.0.0

New documentation and corresponding site.
Use Object.is/the SameValue when checking equality of primitive values (the to be and to equal assertions).
Tweaked the output of numerous assertions.
Constrained to be empty and to have length to only work with strings and array-like objects.
Renamed the arrayLike type to array-like.
Changed style names and added theming support (mostly internal).
Removed grammatically incorrect assertions.

MIT License

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.