Add information about testing requests

README.md

@@ -5,6 +5,8 @@ PHPUnit testcase for testing code that uses WordPress's `WP_Http` class.
 
 # Usage
 
+## Mocking Responses
+
 If you use `wp_remote_request()` or other wrappers for `WP_Http` methods in your
 code, this makes it difficult to test, especially if the remote server may not be
 reachable from your testing environment. This testcase solves this by letting you
@@ -36,3 +38,29 @@ protected function mock_server_response( $request, $url ) {
 For a full list of the `$request` and response arguments, see
 [`WP_Http::request()`](http://developer.wordpress.org/reference/classes/wp_http/
 request/#source-code)
+
+## Testing Requests
+
+You may also wish to test that your code is making requests as expected. You can do
+this by checking the value of `$this->http_requests`, which is an array of requests.
+Each entry in the array stores the request arguments (`'request'` key) and URL
+(`'url'` key).
+
+To check that a request was made, you could do something like this:
+
+```php
+$this->assertCount( 1, $this->http_requests );
+$this->assertEquals( 'http://example.com/', $this->http_requests[0]['url'] );
+```
+
+When you just want to test the request and don't care about the response, you can
+short-circuit the request before it is made, by setting the response mocker to be
+`__return_true()`:
+
+```php
+$this->http_responder = '__return_true';
+
+my_prefix_make_request();
+
+$this->assertCount( 1, $this->http_requests );
+```