PSR-18 Mock HTTP Client

1.1.0 2023-09-22 02:51 UTC

This package is auto-updated.

Last update: 2024-07-08 06:17:27 UTC


Fansipan Mock HTTP Client

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Fansipan mock HTTP client is PSR-18 Client implementation that provides ability send test requests with fake responses.

The MockClient accepts Psr\Http\Message\ResponseInterface which when used on a request, will respond with a fake response without actually sending a real request to the web. This helps speed up tests massively and can help you test your application for different API response scenarios, like a 404 error or 500 error.


You can install the package via composer:

composer require fansipan/mock-client


Creating Mock Client

use Fansipan\Mock\MockClient;

$client = new MockClient();
$response = $client->sendRequest($request);

By default MockClient will always return 200 - OK status code with empty body. If you want to return a different response, create a Psr\Http\Message\ResponseInterface instance and pass it as constructor argument. You can use MockResponse to quickly create a fake response.

use Fansipan\Mock\MockClient;
use Fansipan\Mock\MockResponse;

$client = new MockClient(MockResponse::create('', 500));

Faking Response

The MockResponse class is used to create fake responses. It can accept a body, status, and headers. These properties will be populated in the fake response. The response body accepts an array for a JSON body or plain strings to simulate other responses, like XML.

use Fansipan\Mock\MockResponse;

MockResponse::create(['name' => 'John', 'age' => 30], 201, ['X-Custom-Header' => 'foo']);

You don't have to add ['Content-Type' => 'application/json'] header if your body is array.

If you have fixture data and don't want to create response manually, you can also use fixture method to create a response.

use Fansipan\Mock\MockResponse;


If your fixture is a JSON or XML file, there's no need to add the Content-Type header manually.

Faking Response Sequences

Sequence faking allows you to define a number of fake responses in a specific order. It will pull out the next response in the sequence, removing it from the sequence. Each response can only be consumed once. When all the responses in a response sequence have been consumed, any further requests will cause the response sequence to throw an exception.

use Fansipan\Mock\MockClient;
use Fansipan\Mock\MockResponse;

$client = new MockClient([
    MockResponse::make(['name' => 'foo'], 200),
    MockResponse::make(['name' => 'bar'], 201),
    MockResponse::make(['error' => 'Server Error'], 500),

$client->sendRequest($firstRequest); // Will return with `['name' => 'foo']` and status `200`
$client->sendRequest($secondRequest); // Will return with `['name' => 'bar']` and status `200`
$client->sendRequest($thirdRequest); // Will return with `['error' => 'Server Error']` and status `500`

Faking Specific URLs

Alternatively, you may use ScopingMockClient and pass an array to the constructor argument. The array's keys should represent URL patterns that you wish to fake and their associated responses. The * character may be used as a wildcard character. Any requests made to URLs that have not been faked will actually be executed.

use Fansipan\Mock\MockResponse;
use Fansipan\Mock\ScopingMockClient;

new ScopingMockClient([
    // Stub a JSON response for GitHub endpoints...
    '*' => MockResponse::create(['foo' => 'bar'], 200),

    // Stub a string response for Google endpoints...
    '*' => MockResponse::create('Hello World', 200, $headers),

    // Stub a string response for all other endpoints...
    '*' => MockResponse::create('Hello World', 200, $headers),

Sequence Faking also works with ScopingMockClient

use Fansipan\Mock\MockResponse;
use Fansipan\Mock\ScopingMockClient;

new ScopingMockClient([
    // Stub sequence JSON responses for GitHub endpoints...
    '*' => [
        MockResponse::create(['foo' => 'bar']),
        MockResponse::create(['error' => 'Server Error'], 500),

    // Stub sequence responses for Google endpoints...
    '*' => [
        MockResponse::create('Hello World', 200, $headers),
        MockResponse::create(['baz' => 'qux']),

Adding Expectations

When using faking responses, it's important to be able to check that a specific make request was sent and with the correct data, and headers. MockClient & ScopingMockClient provide you with various ways to add expectations to your tests.

Available Expectations

  • assertSent
  • assetNotSend
  • assertNothingSent
  • assertSentCount

The assertSent / assertNotSent are the two most powerful expectation methods. They can accept a URL pattern or even a closure where you define if a request/response is what you expect.

use Fansipan\Mock\MockClient;
use Psr\Http\Message\RequestInterface;
use Psr\Http\Message\ResponseInterface;

$client = new MockClient();

$request = $requestFactory->createRequest('GET', '');


$client->assertSent(function (RequestInterface $request, ResponseInterface $response): bool {
    return $request->getMethod() === 'GET'
        && (string) $request->getUri() === ''
        && $response->getStatusCode() === 200;


composer test


Please see CHANGELOG for more information on what has changed recently.


Please see CONTRIBUTING and CODE_OF_CONDUCT for details.


If you discover any security related issues, please email instead of using the issue tracker.



The MIT License (MIT). Please see License File for more information.