⚗️ One of the most common integrations developers struggle to test is Guzzle. Fortunately, it has a `MockHandler` you can set up to return predefined responses.
Since it uses the existing `Client` and `Response` objects, there's no need to change your implementation. pic.twitter.com/Ui2Zyqj2Lt
— Jason McCreary (@gonedark) 23 december 2019
Source: Freek Van der Herten