Pact Spring/JUnit5 Support

This module extends the base Pact JUnit5 module. See that for more details.

For writing Spring 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 @ExtendWith(SpringExtension.class) and one of the pact source annotations to your test class (as per a JUnit 5 test), then add a method annotated with @TestTemplate and @ExtendWith(PactVerificationSpringProvider.class) that takes a PactVerificationContext parameter. You will need to call verifyInteraction() on the context parameter in your test template method.

For example:

@ExtendWith(SpringExtension.class)
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.DEFINED_PORT)
@Provider("Animal Profile Service")
@PactBroker
public class ContractVerificationTest {

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

}

You will now be able to setup all the required properties using the Spring context, e.g. creating an application YAML file in the test resources:

pactbroker:
  host: your.broker.host
  auth:
    username: broker-user
    password: broker.password

You can also run pact tests against MockMvc without need to spin up the whole application context which takes time and often requires more additional setup (e.g. database). In order to run lightweight tests just use @WebMvcTest from Spring and MockMvcTestTarget as a test target before each test.

For example:

@WebMvcTest
@Provider("myAwesomeService")
@PactBroker
class ContractVerificationTest {
    
    @Autowired
    private MockMvc mockMvc;

    @TestTemplate
    @ExtendWith(PactVerificationInvocationContextProvider.class)
    void pactVerificationTestTemplate(PactVerificationContext context) {
      context.verifyInteraction();
    }
    
    @BeforeEach
    void before(PactVerificationContext context) {
        context.setTarget(new MockMvcTestTarget(mockMvc));
    }
}

You can also use MockMvcTestTarget for tests without spring context by providing the controllers manually.

For example:

@Provider("myAwesomeService")
@PactFolder("pacts")
class MockMvcTestTargetStandaloneMockMvcTestJava {

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

    @BeforeEach
    void before(PactVerificationContext context) {
        MockMvcTestTarget testTarget = new MockMvcTestTarget();
        testTarget.setControllers(new DataResource());
        context.setTarget(testTarget);
    }

    @RestController
    static class DataResource {
        @GetMapping("/data")
        @ResponseStatus(HttpStatus.NO_CONTENT)
        void getData(@RequestParam("ticketId") String ticketId) {
        }
    }
}

Important: Since @WebMvcTest starts only Spring MVC components you can't use PactVerificationSpringProvider and need to fallback to PactVerificationInvocationContextProvider