Pact Spring/JUnit runner

Overview

Library provides ability to play contract tests against a provider using Spring & JUnit. This library is based on and references the JUnit package, so see the Pact JUnit 4 or Pact JUnit 5 providers for more details regarding configuration using JUnit.

Supports:

  • Standard ways to load pacts from folders and broker

  • Easy way to change assertion strategy

  • Spring Test MockMVC Controllers and ControllerAdvice using MockMvc standalone setup.

  • MockMvc debugger output

  • Spring WebFlux Controllers and RouterFunctions

  • Multiple @State runs to test a particular Provider State multiple times

  • au.com.dius.pact.provider.junit.State custom annotation - before each interaction that requires a state change, all methods annotated by @State with appropriate the state listed will be invoked.

NOTE: For publishing provider verification results to a pact broker, make sure the Java system property pact.provider.version is set with the version of your provider.

Example of MockMvc test

@RunWith(RestPactRunner.class) // Custom pact runner, child of PactRunner which runs only REST tests
@Provider("myAwesomeService") // Set up name of tested provider
@PactFolder("pacts") // Point where to find pacts (See also section Pacts source in documentation)
public class ContractTest {
//Create an instance of your controller. We cannot autowire this as we're not using (and don't want to use) a Spring test runner.
@InjectMocks
private AwesomeController awesomeController = new AwesomeController();
//Mock your service logic class. We'll use this to create scenarios for respective provider states.
@Mock
private AwesomeBusinessLogic awesomeBusinessLogic;
//Create an instance of your controller advice (if you have one). This will be passed to the MockMvcTarget constructor to be wired up with MockMvc.
@InjectMocks
private AwesomeControllerAdvice awesomeControllerAdvice = new AwesomeControllerAdvice();
//Create a new instance of the MockMvcTarget and annotate it as the TestTarget for PactRunner
@TestTarget
public final MockMvcTarget target = new MockMvcTarget();
@Before //Method will be run before each test of interaction
public void before() {
//initialize your mocks using your mocking framework
MockitoAnnotations.initMocks(this);
//configure the MockMvcTarget with your controller and controller advice
target.setControllers(awesomeController);
target.setControllerAdvice(awesomeControllerAdvice);
}
@State("default", "no-data") // Method will be run before testing interactions that require "default" or "no-data" state
public void toDefaultState() {
target.setRunTimes(3); //let's loop through this state a few times for a 3 data variants
when(awesomeBusinessLogic.getById(any(UUID.class)))
.thenReturn(myTestHelper.generateRandomReturnData(UUID.randomUUID(), ExampleEnum.ONE))
.thenReturn(myTestHelper.generateRandomReturnData(UUID.randomUUID(), ExampleEnum.TWO))
.thenReturn(myTestHelper.generateRandomReturnData(UUID.randomUUID(), ExampleEnum.THREE));
}
@State("error-case")
public void SingleUploadExistsState_Success() {
target.setRunTimes(1); //tell the runner to only loop one time for this state
//you might want to throw exceptions to be picked off by your controller advice
when(awesomeBusinessLogic.getById(any(UUID.class)))
.then(i -> { throw new NotCoolException(i.getArgumentAt(0, UUID.class).toString()); });
}
}

Example of Spring WebFlux test

@RunWith(RestPactRunner.class) // Custom pact runner, child of PactRunner which runs only REST tests
@Provider("myAwesomeService") // Set up name of tested provider
@PactFolder("pacts") // Point where to find pacts (See also section Pacts source in documentation)
public class AwesomeRouterContractTest {
//Create a new instance of the WebFluxTarget and annotate it as the TestTarget for PactRunner
@TestTarget
public WebFluxTarget target = new WebFluxTarget();
//Create instance of your RouterFunction
public RouterFunction<ServerResponse> routerFunction
= new AwesomeRouter(new AwesomeHandler()).routes();
//Configure the WebFluxTarget with routerFunction
@Before
public void setup() {
target.setRouterFunction(routerFunction);
}
}

Using Spring runners

You can use SpringRestPactRunner or SpringMessagePactRunner instead of the default Pact runner to use the Spring test annotations. This will allow you to inject or mock spring beans. SpringRestPactRunner is for restful webapps and SpringMessagePactRunner is for async message tests.

For example:

@RunWith(SpringRestPactRunner.class)
@Provider("pricing")
@PactBroker(protocol = "https", host = "${pactBrokerHost}", port = "443",
authentication = @PactBrokerAuth(username = "${pactBrokerUser}", password = "${pactBrokerPassword}"))
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.DEFINED_PORT)
public class PricingServiceProviderPactTest {
@MockBean
private ProductClient productClient; // This will replace the bean with a mock in the application context
@TestTarget
@SuppressWarnings(value = "VisibilityModifier")
public final Target target = new HttpTarget(8091);
@State("Product X010000021 exists")
public void setupProductX010000021() throws IOException {
reset(productClient);
ProductBuilder product = new ProductBuilder()
.withProductCode("X010000021");
when(productClient.fetch((Set<String>) argThat(contains("X010000021")), any())).thenReturn(product);
}
@State("the product code X00001 can be priced")
public void theProductCodeX00001CanBePriced() throws IOException {
reset(productClient);
ProductBuilder product = new ProductBuilder()
.withProductCode("X00001");
when(productClient.find((Set<String>) argThat(contains("X00001")), any())).thenReturn(product);
}
}

Using Spring Context Properties

The SpringRestPactRunner will look up any annotation expressions (like ${pactBrokerHost}) above) from the Spring context. For Springboot, this will allow you to define the properties in the application test properties.

For instance, if you create the following application.yml in the test resources:

pactbroker:
host: "your.broker.local"
port: "443"
protocol: "https"
auth:
username: "<your broker username>"
password: "<your broker password>"

Then you can use the defaults on the @PactBroker annotation.

@RunWith(SpringRestPactRunner.class)
@Provider("My Service")
@PactBroker(
authentication = @PactBrokerAuth(username = "${pactbroker.auth.username}", password = "${pactbroker.auth.password}")
)
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class PactVerificationTest {

Using a random port with a Springboot test

If you use a random port in a springboot test (by setting SpringBootTest.WebEnvironment.RANDOM_PORT), you need to set it to the TestTarget. How this works is different for JUnit4 and JUnit5.

JUnit4

You can use the SpringBootHttpTarget which will get the application port from the spring application context.

For example:

@RunWith(SpringRestPactRunner.class)
@Provider("My Service")
@PactBroker
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class PactVerificationTest {
@TestTarget
public final Target target = new SpringBootHttpTarget();
}

JUnit5

You actually don't need to dependend on pact-jvm-provider-spring for this. It's sufficient to depend on pact-jvm-provider-junit5.

You can set the port to the HttpTestTarget object in the before method.

@Provider("My Service")
@PactBroker
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class PactVerificationTest {
@LocalServerPort
private int port;
@BeforeEach
void before(PactVerificationContext context) {
context.setTarget(new HttpTestTarget("localhost", port));
}
}
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