Testing a web adapter with integration tests

Moving outward another layer, we arrive at our adapters. Let’s discuss testing a web adapter.

Recall that a web adapter takes input, for example, in the form of JSON strings, via HTTP, might do some validation on it, maps the input to the format a use case expects, and then passes it to that use case. It then maps the result of the use case back to JSON and returns it to the client via an HTTP response.

In the test for a web adapter, we want to make certain that all those steps work as expected:

The preceding test is a standard integration test for a web controller named SendMoneyController, built with the Spring Boot framework. In the testSendMoney() method, we send a mock HTTP request to the web controller to trigger a transaction from one account to another.

With the isOk() method, we then verify that the status of the HTTP response is 200, and we verify that the mocked use case class has been...