Slack logo
Need help?

Using WireMock with Pact

Disclaimer: This solution page includes resources maintained by their authors outside the WireMock organization on GitHub. The info is provided as is without guarantees unless explicitly specified. Referenced projects and guidelines might be incompatible with the recent WireMock 3.x releases or the recent versions of the target technology or framework.

Please use with caution, and submit GitHub issues or pull requests to this page and referenced repositories if something is missing, broken or needs update.

WireMock Pact #

WireMock Pact will get the requests from WireMock and create Pact JSON files on the filesystem. The Pact JSON can be published to a Pactflow broker.

WireMock Pact contains:

  • wiremock-pact-lib - A library that can transform WireMock ServeEvent:s to Pact JSON.
  • wiremock-pact-extension-junit5 - A WireMock extension, and JUnit 5, that is intended to ease usage of the library.
  • wiremock-pact-example-springboot-app - A SpringBoot application that shows how it can be used.

WireMock Pact is released to Maven Central. And available on GitHub.

Usage - Junit 5 #

The extension is both a WireMock extension and a JUnit 5 extension. When using wiremock-spring-boot it can be configured like this in a base class of your tests:

import com.github.tomakehurst.wiremock.core.WireMockConfiguration;
import com.maciejwalkowiak.wiremock.spring.ConfigureWireMock;
import com.maciejwalkowiak.wiremock.spring.EnableWireMock;
import com.maciejwalkowiak.wiremock.spring.WireMockConfigurationCustomizer;
import org.junit.jupiter.api.extension.RegisterExtension;
import se.bjurr.wiremockpact.wiremockpactextensionjunit5.WireMockPactExtension;
import se.bjurr.wiremockpact.wiremockpactlib.api.WireMockPactConfig;

@EnableWireMock({
  @ConfigureWireMock(
      name = "wiremock-service-name",
      property = "wiremock.server.url",
      stubLocation = "wiremock",
      configurationCustomizers = {WireMockPactBaseTest.class})
})
public class WireMockPactBaseTest implements WireMockConfigurationCustomizer {
  @RegisterExtension
  static WireMockPactExtension WIREMOCK_PACT_EXTENSION =
      new WireMockPactExtension(
          WireMockPactConfig.builder() //
              .setConsumerDefaultValue("WireMockPactExample") //
              .setProviderDefaultValue("UnknownProvider") //
              .setPactJsonFolder("src/test/resources/pact-json"));

  @Override
  public void customize(
      final WireMockConfiguration configuration, final ConfigureWireMock options) {
    configuration.extensions(WIREMOCK_PACT_EXTENSION);
  }
}

Usage - Library #

It can be used as a library.

public class ExampleTest {
  private static WireMockServer server;
  private static WireMockPactApi wireMockPactApi;

  @BeforeAll
  public static void beforeEach() throws IOException {
    server = new WireMockServer();
    server.start();

    stubFor(
        post(anyUrl())
            .willReturn(
                ok()
                .withHeader("content-type", "application/json")
                .withBody("""
                {"a":"b"}
                """))
            .withMetadata(
                new Metadata(
                    Map.of(
                        WireMockPactMetadata.METADATA_ATTR,
                        new WireMockPactMetadata()
                            .setProvider("some-specific-provider")))));

    wireMockPactApi =
        WireMockPactApi.create(
            new WireMockPactConfig()
                .setConsumerDefaultValue("my-service")
                .setProviderDefaultValue("unknown-service")
                .setPactJsonFolder("the/pact-json/folder"));
    wireMockPactApi.clearAllSaved();
  }

  @Test
  public void testInvoke() {
    // Do stuff that invokes WireMock...
  }

  @AfterAll
  public static void after() {
    for (final ServeEvent serveEvent : server.getAllServeEvents()) {
      wireMockPactApi.addServeEvent(serveEvent);
    }
    // Save pact-json to folder given in WireMockPactApi
    wireMockPactApi.saveAll();
    server.stop();
  }
}

Mappings metadata - Set provider in mapping #

You can adjust any mappings file like this to specify the provider of a mapping in its metadata field:

{
  "id" : "d68fb4e2-48ed-40d2-bc73-0a18f54f3ece",
  "request" : {
    "urlPattern" : "/animals/1",
    "method" : "GET"
  },
  "response" : {
    "status" : 202
  },
  "uuid" : "d68fb4e2-48ed-40d2-bc73-0a18f54f3ece",
+  "metadata": {
+   "wireMockPactSettings": {
+     "provider":"some-other-system"
+   }
+  }
}

Or programmatically:

    stubFor(
        post(anyUrl())
            .withMetadata(
                new Metadata(
                    Map.of(
                        WireMockPactMetadata.METADATA_ATTR,
                        new WireMockPactMetadata()
                            .setProvider("some-specific-provider")))));

Publishing to Pact broker #

Pact has a CLI tool that can be used for publishing the contracts. But it requires Ruby or Docker. If you don’t have that, perhaps curl is an option. There is a shell script here that can also be used via NPM.

You may want to use something like git-changelog-command-line to get the next version.

There is a test-server at https://test.pactflow.io/ that can be accessed with user dXfltyFMgNOFZAxr8io9wJ37iUpY42M and password O5AIZWxelWbLvqMd8PkAVycBJh2Psyg1.

current_version=$(npx git-changelog-command-line \
  --patch-version-pattern "^fix.*" \
  --print-current-version)
git_hash=`git rev-parse --short HEAD`
participant_version_number="$current_version-$git_hash"

npx pactflow-publish-sh \
 --username=dXfltyFMgNOFZAxr8io9wJ37iUpY42M \
 --password=O5AIZWxelWbLvqMd8PkAVycBJh2Psyg1 \
 --pactflow-broker-url=https://test.pactflow.io/contracts/publish \
 --build-url=http://whatever/ \
 --pact-json-folder=wiremock-pact-example-springboot-app/src/test/resources/pact-json \
 --participant-version-number=$participant_version_number

Useful pages #