This project contains a very simple demo of using consumer-driven contracts to verify the interactions between microservices. It leverages Spring Boot for both the provider and consumer services.

Testing is achieved using the pact-jvm project, which is a JVM port of the original pact.

1. Run the tests using Gradle:

   $ gradle test

2. This will result in the creation of a pact file called Foo_Consumer-Foo_Provider.json at microservices-pact/microservices-pact-consumer/target/pacts. Here’s a current example:

   {
     "provider" : {
       "name" : "Foo_Provider"
     },
     "consumer" : {
       "name" : "Foo_Consumer"
     },
     "interactions" : [ {
       "description" : "a request for Foos",
       "request" : {
         "method" : "GET",
         "path" : "/foos"
       },
       "response" : {
         "status" : 200,
         "headers" : {
           "Content-Type" : "application/json;charset=UTF-8"
         },
         "body" : [ {
           "value" : 42
         }, {
           "value" : 100
         } ]
       }
     } ],
     "metadata" : {
       "pact-specification" : {
         "version" : "2.0.0"
       },
       "pact-jvm" : {
         "version" : "2.1.7"
       }
     }
   }

   By virtue of the fact that these tests pass, we know that the microservices-pact-consumer app interacts appropriately with the contract as defined in ConsumerPortTest.java.

3. Next, we want to verify that the microservices-pact-provider app actually provides the expected contract. First, build the apps:

   $ gradle assemble

4. Next, in one terminal window, start up the provider app:

   $ java -jar microservices-pact-provider/build/libs/microservices-pact-provider-0.0.1-SNAPSHOT.jar

5. Then, in another terminal window, run the pact verification:

   $ gradle pactVerify

   You should see output along these lines:

   $ gradle pactVerify
   :microservices-pact-provider:pactVerify_fooProvider
   
   Verifying a pact between fooConsumer and fooProvider
     [Using file /Users/pivotal/workspace/microservices-pact/microservices-pact-consumer/target/pacts/Foo_Consumer-Foo_Provider.json]
     a request for Foos
       returns a response which
         has status code 200 (OK)
         includes headers
           "Content-Type" with value "application/json;charset=UTF-8" (OK)
         has a matching body (OK)
   :microservices-pact-provider:pactVerify
   
   BUILD SUCCESSFUL