Testing

To test code that uses the WebClient, you can use a mock web server, such as OkHttp MockWebServer or WireMock. Mock web servers accept requests over HTTP like a regular server, and that means you can test with the same HTTP client that is also configured in the same way as in production, which is important because there are often subtle differences in the way different clients handle network I/O. Another advantage of mock web servers is the ability to simulate specific network issues and conditions at the transport level, in combination with the client used in production.

For example use of MockWebServer, see WebClientIntegrationTests in the Spring Framework test suite or the static-server sample in the OkHttp repository.