mock4xhr

Utility for mocking XMLHttpRequests in the browser.

Useful for unit testing and doesn't require you to inject a mocked object into your code.

Installation

Browserify

npm install --save mock4xhr

Component

component install jameslnewell/mock4xhr

Usage

var mock = require('mock4xhr');
 
//replace the real XHR object with the mock XHR object
mock.setup();
 
//create a mock response for all POST requests with the URL http://localhost/api/user
mock.post('http://localhost/api/user', function(req, res) {
 
  //return null;              //simulate an error
  //return res.timeout(true); //simulate a timeout
 
  return res
    .status(201)
    .header('Content-Type', 'application/json')
    .body(JSON.stringify({data: {
      first_name: 'John', last_name: 'Smith'
    }}))
  ;
 
});
 
//create an instance of the (mock) XHR object and use as per normal
var xhr = new XMLHttpRequest();
...
 
xhr.onreadystatechange = function() {
  if (xhr.readyState == 4) {
 
    //when you're finished put the real XHR object back
    mock.teardown();
 
  }
}

Examples

Examples of using mock4xhr with various frameworks:

• Axios
• Superagent
• jQuery
• XMLHttpRequest

API

mock4xhr

.setup()

Replace the global XMLHttpRequest object with the MockXMLHttpRequest.

.teardown()

Restore the global XMLHttpRequest object to its original state.

.reset()

Forget all the request handlers.

.get(url | regex, fn)

Register a factory function to create mock responses for each GET request to a specific URL.

.post(url | regex, fn)

Register a factory function to create mock responses for each POST request to a specific URL.

.put(url | regex, fn)

Register a factory function to create mock responses for each PUT request to a specific URL.

.patch(url | regex, fn)

Register a factory function to create mock responses for each PATCH request to a specific URL.

.delete(url | regex, fn)

Register a factory function to create mock responses for each DELETE request to a specific URL.

.mock(method, url | regex, fn)

Register a factory function to create mock responses for each request to a specific URL.

.mock(fn)

Register a factory function to create mock responses for every request.

MockXMLHttpRequest

MockRequest

.method() : string

Get the request method.

.url() : string

Get the request URL.

.query() : object

Get the parsed query part of the request URL.

.header(name : string) : string

Get a request header.

.headers() : object

Get the request headers.

.body() : string

Get the request body.

MockResponse

.status() : number

Get the response status.

.status(code : number)

Set the response status.

.statusText() : string

Get the response statusText.

.statusText(statusText : string)

Set the response statusText.

.header(name : string, value: string)

Set a response header.

.header(name : string) : string

Get a response header.

.headers() : object

Get the response headers.

.headers(headers : object)

Set the response headers.

.body() : string

Get the response body.

.body(body : string)

Set the response body.

.timeout() : bool|number

Get whether the response will trigger a time out.

.timeout(timeout : bool|number)

Set whether the response will trigger a time out. timeout defaults to the value set on the XHR object.

.progress(loaded : number, total : number, lengthComputable : bool)

Trigger progress event. Pass in loaded size, total size and if event is lengthComputable.

ToDo

• Ability to return mocked responses asynchronously
• Ability to provide a simple object response instead of a function
• Handle JSON and XML response types