# 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)

```javascript
it('should be a teapot', function () {
  return frisby.get('https://httpbin.org/status/418')
    .expect('status', 418);
});
```

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

```javascript
it('should have a JSON Content-Type header', function () {
  return frisby.get('https://httpbin.org/headers')
    .expect('header', 'Content-Type', 'application/json');
});
```

### expect('json' *\[, path]*, data)

```javascript
it('should have a "Host" header with a value of "httpbin.org"', function () {
  return frisby.get('https://httpbin.org/headers')
    .expect('json', 'headers', {
      Host: 'httpbin.org'
    });
});
```

A more complex example:

```javascript
it ('should return a list of feed items', function () {
  return frisby
    .get('https://jsonfeed.org/feed.json')
    .expect('status', 200)
    .expect('json', 'version', 'https://jsonfeed.org/version/1')
    .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(),
      'date_published': Joi.date().iso().required(),
    });
});
```

### expect('jsonTypes' *\[, path]*, data)

```javascript
it('should return all headers as strings', function () {
  return frisby.get('https://httpbin.org/headers')
    // 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()`.

```javascript
it('should not return an error', function () {
  return frisby.get('https://httpbin.org/headers')
    // Should not return an error
    .expectNot('json', { result: 'error' });
});
```


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