Running Assertions

Frisby has many ways of running assertions against the HTTP response. Below are the following methods available by default:

expect(handler, [...args])

Frisby comes with many handy built-in expect handlers to help you test the HTTP response of your API.

  • status - Check HTTP status

  • header - Check HTTP header key + value

  • json - Match json structure + values

  • jsonStrict - Match EXACT json structure + values (extra keys not tested for cause test failures)

  • jsonTypes - Match json structure + value types

  • jsonTypesStrict - Match EXACT json structure + value types (extra keys not tested for cause test failures)

  • bodyContains - Match partial body content (string or regex)

expect('status', statusCode)

it('should be a teapot', function () {
return frisby.get('')
.expect('status', 418);

expect('header', key [, value])

it('should have a JSON Content-Type header', function () {
return frisby.get('')
.expect('header', 'Content-Type', 'application/json');

expect('json' [, path], data)

it('should have a "Host" header with a value of ""', function () {
return frisby.get('')
.expect('json', 'headers', {
Host: ''

A more complex example:

it ('should return a list of feed items', function () {
return frisby
.expect('status', 200)
.expect('json', 'version', '')
.expect('json', 'title', 'JSON Feed')
.expect('jsonTypes', 'items.*', { // Assert *each* object in 'items' array
'id': Joi.string().required(),
'url': Joi.string().uri().required(),
'title': Joi.string().required(),

expect('jsonTypes' [, path], data)

it('should return all headers as strings', function () {
return frisby.get('')
// Using a wildcard in the path '*' check EACH value
.expect('jsonTypes', 'headers.*', frisby.Joi.string());

expectNot(handler, [...args])

Runs an inverse assertion that passes when there is an error thrown. Uses all the same types and arguments as expect().

it('should not return an error', function () {
return frisby.get('')
// Should not return an error
.expectNot('json', { result: 'error' });