Labs around Consumer Driven Contracts (CDC) with Pact and its Broker
Code source is written in C# on .Net Core.

Clone repo

git clone https://github.com/agilepartner/pact-sandbox.git

Projects

AgilePartner.Pact.Lib

Utilities to do CDC with Pact :

• RestProxy a simple Rest Proxy.
• PactFixture Represents a shared context for xunit tests. On Dispose it will publish Pact file
  • On disk (folder pacts/)
  • In a broker (on "http://localhost")
• client_should base class for consumers tests (initialize PactFixture).

AgilePartner.Pact.Consumers

This solution contains Consumers project (called ClientX)
Each Consumer project contains a Client class and a client_should (test class).

The tests define the expected behaviors from the consumer regarding the provider and check the behavior of the client based on the contract defined in the test :

    [Fact]
    public async Task get_helloworldv1()
    {
        mockProviderService
            .Given("Client1 get at helloworld")
            .UponReceiving("A message")
            .With(new ProviderServiceRequest
            {
                Method = HttpVerb.Get,
                Path = "/api/v1.0/helloworld"
            })
            .WillRespondWith(new ProviderServiceResponse
            {
                Status = 200,
                Headers = new Dictionary<string, object>
                {
                    { "Content-Type", "application/json; charset=utf-8" },
                },
                Body = new
                {
                    message = "Hello world v1"
                }
            });

        await consumer.GetHello();

        mockProviderService.VerifyInteractions();
    }

AgilePartner.Pact.Providers

This solution contains :

• a Provider project containing an HelloWorld api with GET implemented in 4 versions.
• a test project in which we design our api based on the contract(s) defined by the consumers.

    public helloworld_api_should(
        ITestOutputHelper output)
    {
        this.config = new PactVerifierConfig
        {
            Outputters = new List<IOutput> { new XUnitOutput(output) },
            PublishVerificationResults = true,
            ProviderVersion = "1.0.0"
        };
    }

    private void VerifyContractWithConsumer(string consumerName)
    {
        IPactVerifier pactVerifier = new PactVerifier(config);
        pactVerifier
            .ServiceProvider("Helloworld", SERVER_URI)
            .HonoursPactWith(consumerName)
            .PactUri($"http://localhost/pacts/provider/HelloWorld/consumer/{ consumerName }/latest")
            .Verify();
    }

    [Fact]
    public void respect_its_contract_with_client1()
    {
        VerifyContractWithConsumer("Client1");
    }

Start the Pact broker

The solutions download the pact contracts expressed as json from a pact broker.

cd broker
docker-compose up

The broker can be accessed at http://localhost/

Setup contracts in your broker

• Run consumer tests, it will publish the contracts

• Run provider tests, it will publish the verification results

• Then you can browse dependencies graph

Webhook

Here is the documentation Create webhook

Create a webhook

{
  "provider": {
    "name": "HelloWorld"
  },
  "events": [{
    "name": "contract_content_changed"
  }],
  "request": {
    "method": "POST",
    "url": "https://hooks.slack.com/services/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",
    "headers": {
      "Accept": "application/json"
    },
    "body": {
      "text" : "Contract for provider HelloWorld has been updated."
    }
  }
}

In other languages :

• js