Consumer Driven Contracts Using Pact Framework

Projects

Project	Description
pact-contract-provider	provider application
pact-contract-consumer	consumer application

Compatability Matrix

choose the branch based on below maintained versions.

Branch/Version	Spring Boot	Pact Broker
master	2.2.6.RELEASE	4.0.10
v2.0	2.1.5.RELEASE	3.5.7
v1.0	1.5.7.RELEASE	3.5.7

Run Pact Broker

• Start pact broker as docker containers

$ cd contract-pact-springboot
$ docker-compose up -d

• View Pact broker url

Guide for Pact Consumer

Start with consumer first, As it is consumer driven contract framework.

• Add below dependencies in pom.xml

        	 <dependency>
		    <groupId>au.com.dius</groupId>
		    <artifactId>pact-jvm-consumer-junit_2.12</artifactId>
		    <version>3.6.7</version>
		    <scope>test</scope>
		</dependency>

• Add pact jvm provider maven plugin

	    <plugin>
                <groupId>au.com.dius</groupId>
                <artifactId>pact-jvm-provider-maven_2.12</artifactId>
                <version>3.6.7</version>
                <configuration>
                   <pactBrokerUrl>${pact.broker.url}</pactBrokerUrl>
		   <pactDirectory>target/pacts</pactDirectory>               
                </configuration>
            </plugin>

• Write the consumer contract test

public class SaveInventoryConsumerTest{
	
    @Rule
    public PactProviderRule mockProvider = new PactProviderRule("inventory_provider","localhost", 8080, this);
    private RestTemplate restTemplate=new RestTemplate();


    @Pact(provider = "inventory_provider", consumer = "inventory_consumer")
    public RequestResponsePact createPact(PactDslWithProvider builder) {
        Map<String, String> headers = new HashMap<>();
        headers.put("Content-Type", MediaType.APPLICATION_JSON_VALUE);


        PactDslJsonBody bodyResponse = new PactDslJsonBody()
                .stringValue("productName", "TV")
                 .stringType("locationName", "CHENNAI")               
                .integerType("quantity", 100);

        return builder
        		.given("create inventory").uponReceiving("a request to save inventory")
                .path("/api/inventory")
                .body(bodyResponse)
                .headers(headers)
                .method(RequestMethod.POST.name())
                .willRespondWith()
                .headers(headers)
                .status(200).body(bodyResponse).toPact();
    }

   

	
	
	@Test
	@PactVerification
	public void testCreateInventoryConsumer() throws IOException {
		
		Inventory inventory=new Inventory("TV", "CHENNAI", 100);
    	HttpHeaders headers=new HttpHeaders();
    	headers.setContentType(MediaType.APPLICATION_JSON);
    	HttpEntity<Object> request=new HttpEntity<Object>(inventory, headers);
    	System.out.println("MOCK provider URL"+mockProvider.getUrl());
    	ResponseEntity<String> responseEntity=restTemplate.postForEntity(mockProvider.getUrl()+"/api/inventory", request, String.class);
    	assertEquals("TV", JsonPath.read(responseEntity.getBody(),"$.productName"));
    	assertEquals("CHENNAI", JsonPath.read(responseEntity.getBody(),"$.locationName"));
    	assertEquals((Integer)100, (Integer)JsonPath.read(responseEntity.getBody(),"$.quantity"));
	}

}

• Run maven build to publish the pacts to the pact broker

cd pact-contract-consumer
mvn clean install pact:publish -Dpact.broker.url=http://localhost:8500

• Verify the pact broker with the contracts

Guide for Pact Provider

Now move on to provider side

• Add the below dependencies in pom.xml

     	<properties>		
		<pact.version>4.0.10</pact.version>
	</properties>
	<dependency>
	    <groupId>au.com.dius</groupId>
	    <artifactId>pact-jvm-provider-junit</artifactId>
	    <version>${pact.version}</version>
	    <scope>test</scope>
	</dependency>
	 <dependency>
	    <groupId>au.com.dius</groupId>
	    <artifactId>pact-jvm-provider-spring</artifactId>
	    <version>${pact.version}</version>
	    <scope>test</scope>
	</dependency>

• Add the pact provider test case

Test case to test against the pacts from the pact broker to test against the pacts from the pact broker

@RunWith(SpringRestPactRunner.class)
@SpringBootTest(classes=PactContractProviderApplication.class,properties={"spring.profiles.active=test","spring.cloud.config.enabled=false"},webEnvironment = SpringBootTest.WebEnvironment.DEFINED_PORT)
@ActiveProfiles("test")
@PactBroker(host="localhost",port="8500")
@Provider("inventory_provider")
public class InventoryProviderTest {
	
	  @MockBean
	  private InventoryService inventoryService;

	  @TestTarget
	  public final Target target = new HttpTarget(9050);
  
	  @State(value="create inventory")
	  public void createInventoryState() throws Exception{

	      Inventory inventory=new Inventory("TV", "CHENNAI", 100);
	      when(inventoryService.saveInventory(any(Inventory.class))).thenReturn(inventory) ;
	  }
} 

• Run maven build at the provider side

cd pact-contract-provider
mvn clean install  -Dpact.verifier.publishResults=true
(or)
mvn test -Dpact.verifier.publishResults=true

Notes:

1. Using @PactBroker(host="localhost",port="8500") to define the pact broker host and port.
2. Using SpringRestPactRunner to load the spring container using @SpringBootTest.
3. Starting the application server using the line new HttpTarget(9050).
4. Mentioning Pact broker url and Pact directory is key to generate pacts at the consumer side.