Spring Cloud Contract Demo

Description

This a demo Spring Boot application that demonstrates the implementation of consumer-driven contract tests with the Spring Cloud Contract framework. The project contains two modules, namely an API provider (cloud-contract-provider) and an API consumer (cloud-contract-consumer). There are three contracts, as one contract defines a single request/response pair. The table below lists the different contracts and the endpoints they define:

Endpoint	Contract file
POST   /books	shouldCreateBook.groovy
GET     /books/{id}	shouldFindBookById.groovy
PUT     /books/{id}	shouldUpdateBook.groovy

Both the API provider and consumer (including tests) are implemented Java. A list comprising the used frameworks/technologies is given below:

  Java                      11
  Gradle                    6.2.2
  Spring Boot               2.2.5.RELEASE
  Spring Cloud Contract     2.2.2.RELEASE

Building & Running the tests

The complete project can be built with the following command executed at top level:

./gradlew clean build

The server tests will be generated from the contracts located in cloud-contract-producer/src/test/resources/contracts/booksapi. The Gradle task check will generate and run the generated server tests (executed in the cloud-contract-producer directory):

./gradlew check

In order to be able to write the tests for the client side (API consumer) we need a stub implementation of the server contracts. The Gradle task verifierStubsJar generates the client stubs and packages them in a JAR file. The JAR file can be published to local Maven repository with the following task (executed in the cloud-contract-producer directory):

./gradlew publishStubsPublicationToMavenLocal

This will generate and publish the cloud-contract-producer-0.0.1-SNAPSHOT-stubs.jar JAR file to the local Maven repository. On the consumer side we use the AutoConfigureStubRunner annotation to run the server stubs. Here in the id attribute we specify the coordinates of the previously generated artifact and the port on which the server stubs will run. Additionally, we specify the location of the generated stubs, which in our case is LOCAL (the stubs will be fetched from a local Maven repository):

@AutoConfigureStubRunner(ids = "com.bzb.spring.cloud:cloud-contract-producer:0.0.1-SNAPSHOT:stubs:8001", stubsMode = StubRunnerProperties.StubsMode.LOCAL)

Finally, we can execute the client tests with the command executed in the cloud-contract-consumer directory:

./gradlew clean check