The `TestClient` class is a custom `protevus_client` that sends mock requests to your server. This means that you will not have to bind your server to HTTP to run. Plus, it is an `protevus_client`, and thus supports services and other goodies. The `TestClient` also supports WebSockets. WebSockets cannot be mocked (yet!) within this library, so calling the `websocket()` function will also bind your server to HTTP, if it is not already listening. The return value is a `WebSockets` client instance (from [`package:protevus_websocket`](<https://pub.dev/packages/protevus_websocket>));
`hasValidBody` is one of the most powerful `Matcher`s in this library, because it allows you to validate a JSON body against a validation schema. Protevus provides a comprehensive [validation library](<https://pub.dev/packages/protevus_validate>) that integrates tightly with the `matcher` package that you already use for testing.