Example consumer contract test

consumer.test.ts

import { Pact } from "@pact-foundation/pact";
import { like } from "@pact-foundation/pact/src/dsl/matchers";
import { CartApi } from ".";

const provider = new Pact({
  consumer: "MockCartConsumer",
  provider: "CartService",
  logLevel: "info",
});

describe("Cart Api", () => {
  let api: { sayHello(): Promise<any> };

  beforeAll(async () => {
    await provider.setup().then((opts) => {
      const baseURL = "http://" + [opts.host, opts.port].join(":");
      api = CartApi(baseURL);
    });
  });

  afterAll(() => provider.finalize());

  test("GET /hello", async () => {
    await provider.addInteraction({
      state: "stateless",
      uponReceiving: "say hello",
      withRequest: {
        method: "GET",
        path: "/hello",
      },
      willRespondWith: {
        status: 200,
        headers: {
          "Content-Type": "application/json",
        },
        body: like({ hello: "world" }),
      },
    });

    await expect(api.sayHello()).resolves.toEqual({ hello: "world" });
  });
});

The way this works is you're encouraged to write your consumer tests first.

For a consumer test, this creates a mock provider that returns stubbed responses, however once you publish the contract and attempt to verify the provider side, it makes live requests and matches them against the stubbed responses - this is kind of like a reverse order of the Ruby/Rails VCR paradigm.

This is super sane/sensible 👍