chai-properties

$3

``bash
npm install --save chai-properties
`

Properties matcher for chai

Make assertions that values have all the same attributes and values without asserting strict object equality.

$3

include chai properties after chai:

`html



`

$3

have chai use chai-properties:

`js
var chai = require('chai');
chai.use(require('chai-properties'));
`

Assertions

$3

partially compare object attributes and values

`js
var subject = { a: 'a', b: 'b', c: 'c' };
subject.should.have.properties({ a: 'a' });
subject.should.have.properties({ a: 'a', b: 'b' });
subject.should.not.have.properties({ a: 'a', z: 'z' });
subject.should.not.have.properties({ a: '1' });

expect(subject).to.have.properties({ a: 'a' });
expect(subject).to.have.properties({ a: 'a', b: 'b' });
expect(subject).to.not.have.properties({ a: 'a', z: 'z' });
expect(subject).to.not.have.properties({ a: '1' });

assert.haveProperties(subject, { a: 'a' });
assert.haveProperties(subject, { a: 'a', b: 'b' });
assert.notHaveProperties(subject, { a: 'a', z: 'z' });
assert.notHaveProperties(subject, { a: '1' });
`

Difference between expectation and actual result

properties assertion will show difference between expectation and actual result when asserion will fail.

`js
var subject = { a: 'a', b: 'b', c: 'c' };
expect(subject).to.have.properties({ a: 'a', b: 'c' });
`

`
AssertionError: expected { a: 'a', b: 'b', c: 'c' }
to have properties { a: 'a', b: 'c' }, but found { a: 'a', b: 'b' }

+ expected - actual

{
"a": "a"
- "b": "b"
- "c": "c"
+ "b": "c"
}
``