Dogfooding Contract to test our internal tools

Our testing framework wouldn't be of any use to anyone else if we weren't willing to use it ourselves .... so, we went about dogfooding contract to test one of our internal tools.

A quick recap on Contract
Contract is an open source testing tool aimed at simplifying the testing of HTTP clients and servers, late stage integration testing is a nightmare that Contract is the perfect solution to. Server facing tests are be driven using a contract that specifies how the server is to react given a HTTP request. Client facing tests are be driven by an identical contract specifying that when a client makes a specific request, they should receive a specific response. With both sides of a client server relationship available for testing at a significantly earlier stage, we can improve the feedback of our testing cycles, and hopefully deliver value that little bit quicker.

What are we trying to test?

We have an application called Autodoc that we're eventually going to deploy to a servlet container. It exposes back end services via a REST API. We've a simple front end that acts as a UI to the back end services. We want the back end to be as stand alone as possible and maintain as high a degree of separation as possible from the front end. To that end, we will be doing no actual end to end testing of the application, we'll be leveraging Contract to test both halves of the application independently.  We use maven as a build tool and will be chaining together a few plugins to do the heavy lifting of our tests.

Step 1 : We use the maven cargo plugin to deploy our application, we override the connection details between the front and back end so we can introduce the contract server & client

Step 2 : Bring up a contract server for the front end to test against. This is the server the front end will actually be communicating with.

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<plugin> <artifactId>contract-maven-plugin</artifactId> <groupId>org.seekay</groupId> <version>${contract.version}</version> <executions> <execution> <id>client_facing_tests</id> <phase>pre-integration-test</phase> <goals> <goal>start-server</goal> </goals> <configuration> <gitSource>${git.url}</gitSource> <port>${back-end-port}</port> <username>${git.username}</username> <password>${git.password}</password> </configuration> </execution> </executions> </plugin>

We're using our new 'start-server' maven goal to bring up a contract server that'll remain active until the maven build finishes.

Step 3 : Execute the front end tests. We're using Cucumber & selenium to test our front end backed by our Contract server. We're executing the tests with the surefire plugin, nothing special to see here. 

Step 4 : Execute the back end tests. We'll be using the Contract client to execute tests against the actual back end. 

<plugin>
    <artifactId>contract-maven-plugin</artifactId>
    <groupId>org.seekay</groupId>
    <version>${contract.version}</version>
    <executions>
        <execution>
            <id>server_facing_tests</id>
            <phase>integration-test</phase>
            <goals>
                <goal>run-client</goal>
            </goals>
            <configuration>
                <gitSource>
                    ${git.url}
                </gitSource>
                <target>http://localhost:${front-end-port}</target>
                <username>${git.username}</username>
                <password>${git.password}</password>
            </configuration>
        </execution>
    </executions>
</plugin>

And we end up with completely independent symmetrical testing of a client server application with Contract.  

Contract is available from Maven Central and docs from github pages  here

Contract is open source