README.md

Pact Junit 5 Extension

Overview

For writing Pact verification tests with JUnit 5, there is an JUnit 5 Invocation Context Provider that you can use with the @TestTemplate annotation. This will generate a test for each interaction found for the pact files for the provider.

To use it, add the @Provider and one of the pact source annotations to your test class (as per a JUnit 4 test), then add a method annotated with @TestTemplate and @ExtendWith(PactVerificationInvocationContextProvider.class) that takes a PactVerificationContext parameter. You will need to call verifyInteraction() on the context parameter in your test template method.

For example:

@Provider("myAwesomeService")
@PactFolder("pacts")
public class ContractVerificationTest {

    @TestTemplate
    @ExtendWith(PactVerificationInvocationContextProvider.class)
    void pactVerificationTestTemplate(PactVerificationContext context) {
      context.verifyInteraction();
    }

}

For details on the provider and pact source annotations, refer to the Pact junit runner docs.

Test target

You can set the test target (the object that defines the target of the test, which should point to your provider) on the PactVerificationContext, but you need to do this in a before test method (annotated with @BeforeEach). There are three different test targets you can use: HttpTestTarget, HttpsTestTarget and AmpqTestTarget.

For example:

  @BeforeEach
  void before(PactVerificationContext context) {
    context.setTarget(HttpTestTarget.fromUrl(new URL(myProviderUrl)));
    // or something like
    // context.setTarget(new HttpTestTarget("localhost", myProviderPort, "/"));
  }

Note for Maven users: If you use Maven to run your tests, you will have to make sure that the Maven Surefire plugin is at least version 2.22.1 uses an isolated classpath.

For example, configure it by adding the following to your POM:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <version>2.22.1</version>
    <configuration>
        <useSystemClassLoader>false</useSystemClassLoader>
    </configuration>
</plugin>

Provider State Methods

Provider State Methods work in the same way as with JUnit 4 tests, refer to the Pact junit runner docs.

Using multiple classes for the state change methods

If you have a large number of state change methods, you can split things up by moving them to other classes. You will need to specify the additional classes on the test context in a Before method. Do this with the withStateHandler or setStateHandlers methods. See StateAnnotationsOnAdditionalClassTest for an example.

Modifying the requests before they are sent

Important Note: You should only use this feature for things that can not be persisted in the pact file. By modifying the request, you are potentially modifying the contract from the consumer tests!

Sometimes you may need to add things to the requests that can't be persisted in a pact file. Examples of these would be authentication tokens, which have a small life span. The Http and Https test targets support injecting the request that will executed into the test template method. You can then add things to the request before calling the verifyInteraction() method.

For example to add a header:

    @TestTemplate
    @ExtendWith(PactVerificationInvocationContextProvider.class)
    void testTemplate(PactVerificationContext context, HttpRequest request) {
      // This will add a header to the request
      request.addHeader("X-Auth-Token", "1234");
      context.verifyInteraction();
    }

Objects that can be injected into the test methods

You can inject the following objects into your test methods (just like the PactVerificationContext). They will be null if injected before the supported phase.

Object	Can be injected from phase	Description
PactVerificationContext	@BeforeEach	The context to use to execute the interaction test
Pact	any	The Pact model for the test
Interaction	any	The Interaction model for the test
HttpRequest	@TestTemplate	The request that is going to be executed (only for HTTP and HTTPS targets)
ProviderVerifier	@TestTemplate	The verifier instance that is used to verify the interaction