WireMock Extension for JUnit Jupiter

This module aims to provide a JUnit Jupiter extension that starts a WireMock server before the test suite starts running, so that the rest of the test setup, such as Spring contexts as well as the tests themselves, will be able to access it.

Why not Spring Cloud Contract?

I've used it in the past, and while it's a good module it has a few problems that makes it difficult to use in certain cases. The main problem is that it boots up the WireMock server as part of the Spring context setup, and there's no way to be certain that it's running if a part of that setup needs to perform HTTP requests. A couple of real-world cases are:

• Spring Cloud Vault attempts to fetch secrets from a remote secret service.
• Spring Security OAuth2 Resource Server attempts to configure itself via a OIDC Discovery-URL (/.well-known/openid-configuration).

Prerequisites

• Your code base must be using Java 9 or later.
• You need to include JUnit Jupiter and WireMock to your dependencies as this module doesn't impose any transitive dependencies.

Usage

If you use Maven, you should be able to use the following coordinates:

<dependency>
    <groupId>com.thomaskasene.wiremock</groupId>
    <artifactId>wiremock-junit-extension</artifactId>
    <version>${latest-release.version}</version>
</dependency>

Then you can simply add the @WireMockStubs-annotation to your test class:

@WireMockStubs
public class MyWireMockTest {

    @Test
    void myFirstTest() {
        // ...
    }
}

The result is that a WireMock server will be started before the test context begins, and it will be torn down once the test context finishes its work.

Additionally, the WireMock server's HTTP port will be exposed as a system property. This property's name is wiremock.server.port by default to cater to existing Spring Cloud Contract-users, but it's possible to override it by providing a custom implementation of WireMockStubsConfiguration.getPortPropertyName.

The WireMockStub-interface

This is an optional feature of this tool. When implementations of this interface is registered with the WireMockStubs annotation, an instance of each implementation is created, and your test classes can have them automatically injected into class-level variables. See the example snippet below, or the WireMockStub-class for more details.

@WireMockStubs(NameRegistryStub.class)
public class MyExampleTest {
    private NameRegistryStub nameRegistryStub;

    @Test
    void myStubTest() {
        nameRegistryStub.addNames("Doe, John");
    }
}

Furthermore, if a WireMockStub also implements the com.github.tomakehurst.wiremock.extension.Extension interface, it will be automatically registered with the WireMock server, so it may be referred to by name later.