Adds metadata to contracts (#1466)

fixes #1340
fixes #1078 
fixes #1406

docs/src/main/asciidoc/_attributes.adoc

@@ -30,7 +30,7 @@
 :standalone_pact_path: {samples_path}/standalone/dsl
 :standalone_restdocs_path: {samples_path}/standalone/restdocs
 :tests_path: {core_path}/tests
-:samples_branch: 2.2.x
+:samples_branch: 3.0.x
 :samples_url: https://raw.githubusercontent.com/spring-cloud-samples/spring-cloud-contract-samples/{samples_branch}
 :samples_code: https://github.com/spring-cloud-samples/spring-cloud-contract-samples/tree/{samples_branch}/
 :doc_samples: {core_path}/samples/wiremock-jetty

docs/src/main/asciidoc/_project-features-contract.adoc

@@ -193,6 +193,7 @@ The following sections describe the most common top-level elements:
 * <<contract-dsl-ignoring-contracts>>
 * <<contract-dsl-in-progress>>
 * <<contract-dsl-passing-values-from-files>>
+* <<contract-dsl-metadata>>
 
 [[contract-dsl-description]]
 ==== Description
@@ -437,6 +438,40 @@ include::{contract_kotlin_spec_path}/src/test/resources/contracts/shouldWorkWith
 IMPORTANT: You should use this approach whenever you want to work with binary payloads,
 both for HTTP and messaging.
 
+[[contract-dsl-metadata]]
+==== Metadata
+
+You can add `metadata` to your contract. Via the metadata you can pass in configuration to extensions. Below you can find
+an example of using the `wiremock` key and value being WireMock's `StubMapping` object. Spring Cloud Contract is able to
+patch parts of your generated stub mapping with your custom code. You may want to do that in order to add webhooks, custom
+delays or integrate with third party WireMock extensions.
+
+====
+[source,groovy,indent=0,role="primary"]
+.groovy
+----
+include::{standalone_samples_path}/http-server/src/test/resources/contracts/fraud/shouldReturnFraudStats.groovy[tags=metadata,indent=0]
+----
+
+[source,yaml,indent=0,role="secondary"]
+.yml
+----
+include::{standalone_samples_path}/http-server/src/test/resources/contracts/yml/fraud/shouldReturnFraudStats.yml[tags=metadata,indent=0]
+----
+
+[source,java,indent=0,subs="verbatim,attributes",role="secondary"]
+.java
+----
+include::{verifier_core_path}/src/test/resources/contractsToCompile/contract_rest_with_tags.java[tags=metadata,indent=0]
+----
+
+[source,kotlin,indent=0,subs="verbatim,attributes",role="secondary"]
+.kotlin
+----
+include::{contract_kotlin_spec_path}/src/test/kotlin/org/springframework/cloud/contract/spec/ContractTests.kt[tags=metadata,indent=0]
+----
+====
+
 [[features-http]]
 == Contracts for HTTP
 

docs/src/main/asciidoc/advanced.adoc

@@ -168,6 +168,54 @@ include::{wiremock_tests}/src/test/java/org/springframework/cloud/contract/wirem
 ----
 ====
 
+[[customization-wiremock-from-metadata]]
+=== Customization of WireMock via Metadata
+
+With version 3.0.0 you're able to set `metadata` in your contracts. If you set an entry with key equal to `wiremock` and the value
+will be a valid WireMock's `StubMapping` JSON / map or an actual `StubMapping` object, Spring Cloud Contract will patch the generated
+stub with part of your customization. Let's look at the following example
+
+[source,yaml,indent=0]
+----
+include::{standalone_samples_path}/http-server/src/test/resources/contracts/yml/fraud/shouldReturnFraudStats.yml[tags=metadata,indent=0]
+----
+
+In the `metadata` section we've set an entry with key `wiremock` and its value is a JSON `StubMapping` that sets a delay in the generated stub. Such code allowed us to get the following merged WireMock JSON stub.
+
+[source,json,indent=0]
+----
+{
+  "id" : "ebae49e2-a2a3-490c-a57f-ba28e26b81ea",
+  "request" : {
+    "url" : "/yamlfrauds",
+    "method" : "GET"
+  },
+  "response" : {
+    "status" : 200,
+    "body" : "{\"count\":200}",
+    "headers" : {
+      "Content-Type" : "application/json"
+    },
+    "fixedDelayMilliseconds" : 2000,
+    "transformers" : [ "response-template" ]
+  },
+  "uuid" : "ebae49e2-a2a3-490c-a57f-ba28e26b81ea"
+}
+----
+
+The current implementation allows to manipulate only the stub side (we don't change the generated test). Also, what does not get changed
+are the whole request and body and headers of the response.
+
+[[customization-wiremock-from-metadata-custom-processor]]
+==== Customization of WireMock via Metadata and a Custom Processor
+
+If you want to apply a custom WireMock `StubMapping` post processing, you can under `META-INF/spring.factories` under the
+`org.springframework.cloud.contract.verifier.converter.StubProcessor` key register your own implementation of a stub processor. For your convenience we've created an interface called `org.springframework.cloud.contract.verifier.wiremock.WireMockStubPostProcessor` that is dedicated to WireMock.
+
+You'll have to implement methods to inform Spring Cloud Contract whether the post processor is applicable for a given contract and how should the post processing look like.
+
+IMPORTANT: On the consumer side, when using Stub Runner, remember to pass the custom `HttpServerStubConfigurer` implementation (e.g. the one that extends `WireMockHttpServerStubConfigurer`) where you'll register a custom extension of your choosing. If you don't do so, even you have a custom WireMock extension on the classpath, WireMock will not notice it, won't apply it and will print out a warning statement that the given extension was not found.
+
 [[customization-pluggable-architecture]]
 == Using the Pluggable Architecture
 

docs/src/test/resources/contract.yml

@@ -57,3 +57,15 @@ response:
         regex: bar
       - key: foo3
         predefined:
+metadata:
+  wiremock:
+    "postServeActions": {
+      "webhook": {
+        "headers": {
+          "Content-Type": "application/json"
+        },
+        "method": "POST",
+        "body": "{ \"result\": \"SUCCESS\" }",
+        "url": "http://localhost:56299/callback"
+      }
+    }

samples/standalone/dsl/http-client/src/main/java/com/example/loan/LoanApplicationService.java

@@ -40,6 +40,8 @@ public class LoanApplicationService {
 	private final RestTemplate restTemplate;
 
 	private int port = 6565;
+	
+	private String prefix = "";
 
 	@Autowired
 	public LoanApplicationService(RestTemplateBuilder builder) {
@@ -61,13 +63,17 @@ public class LoanApplicationService {
 
 		// tag::client_call_server[]
 		ResponseEntity<FraudServiceResponse> response = restTemplate.exchange(
-				"http://localhost:" + port + "/fraudcheck", HttpMethod.PUT,
+				"http://localhost:" + port + fraudCheck(), HttpMethod.PUT,
 				new HttpEntity<>(request, httpHeaders), FraudServiceResponse.class);
 		// end::client_call_server[]
 
 		return response.getBody();
 	}
 
+	private String fraudCheck() {
+		return "/" + prefix + "fraudcheck";
+	}
+
 	private LoanApplicationResult buildResponseFromFraudResult(
 			FraudServiceResponse response) {
 		LoanApplicationStatus applicationStatus = null;
@@ -86,7 +92,7 @@ public class LoanApplicationService {
 		HttpHeaders httpHeaders = new HttpHeaders();
 		httpHeaders.add(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE);
 		ResponseEntity<Response> response = restTemplate.exchange(
-				"http://localhost:" + port + "/frauds", HttpMethod.GET,
+				"http://localhost:" + port + "/" + prefix + "frauds", HttpMethod.GET,
 				new HttpEntity<>(httpHeaders), Response.class);
 		return response.getBody().getCount();
 	}
@@ -95,7 +101,7 @@ public class LoanApplicationService {
 		HttpHeaders httpHeaders = new HttpHeaders();
 		httpHeaders.add(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE);
 		ResponseEntity<Response> response = restTemplate.exchange(
-				"http://localhost:" + port + "/drunks", HttpMethod.GET,
+				"http://localhost:" + port + "/"+ prefix + "drunks", HttpMethod.GET,
 				new HttpEntity<>(httpHeaders), Response.class);
 		return response.getBody().getCount();
 	}
@@ -105,7 +111,7 @@ public class LoanApplicationService {
 		httpHeaders.add("Cookie", "name=foo");
 		httpHeaders.add("Cookie", "name2=bar");
 		ResponseEntity<String> response = restTemplate.exchange(
-				"http://localhost:" + port + "/frauds/name", HttpMethod.GET,
+				"http://localhost:" + port + "/" + prefix + "frauds/name", HttpMethod.GET,
 				new HttpEntity<>(httpHeaders), String.class);
 		return response.getBody();
 	}
@@ -114,4 +120,7 @@ public class LoanApplicationService {
 		this.port = port;
 	}
 
+	public void setPrefix(String prefix) {
+		this.prefix = prefix;
+	}
 }

samples/standalone/dsl/http-client/src/test/java/com/example/loan/LoanApplicationServiceTests.java

@@ -20,31 +20,35 @@ import java.io.File;
 import java.io.IOException;
 import java.net.URI;
 import java.nio.file.Files;
+import java.time.Duration;
 
 import com.example.loan.model.Client;
 import com.example.loan.model.LoanApplication;
 import com.example.loan.model.LoanApplicationResult;
 import com.example.loan.model.LoanApplicationStatus;
+import com.github.tomakehurst.wiremock.WireMockServer;
 import com.jayway.jsonpath.DocumentContext;
 import com.jayway.jsonpath.JsonPath;
 import io.restassured.RestAssured;
 import io.restassured.response.ResponseOptions;
 import io.restassured.specification.RequestSpecification;
+import org.assertj.core.api.BDDAssertions;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
-
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.boot.web.client.RestTemplateBuilder;
 import org.springframework.cloud.contract.stubrunner.spring.AutoConfigureStubRunner;
 import org.springframework.cloud.contract.stubrunner.spring.StubRunnerPort;
 import org.springframework.cloud.contract.stubrunner.spring.StubRunnerProperties;
 import org.springframework.http.RequestEntity;
 import org.springframework.http.ResponseEntity;
-
 import org.springframework.web.client.RestTemplate;
 
+import static com.github.tomakehurst.wiremock.client.WireMock.postRequestedFor;
+import static com.github.tomakehurst.wiremock.client.WireMock.urlEqualTo;
 import static com.toomuchcoding.jsonassert.JsonAssertion.assertThatJson;
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -52,7 +56,7 @@ import static org.assertj.core.api.Assertions.assertThat;
 
 @SpringBootTest(webEnvironment = WebEnvironment.NONE)
 @AutoConfigureStubRunner(ids = {
-		"com.example:http-server-dsl:0.0.1:stubs" }, stubsMode = StubRunnerProperties.StubsMode.LOCAL)
+		"com.example:http-server-dsl:0.0.1:stubs"}, stubsMode = StubRunnerProperties.StubsMode.LOCAL)
 public class LoanApplicationServiceTests {
 
 	// end::autoconfigure_stubrunner[]
@@ -65,6 +69,7 @@ public class LoanApplicationServiceTests {
 
 	@BeforeEach
 	public void setup() {
+		this.service.setPrefix("");
 		this.service.setPort(this.stubPort);
 	}
 
@@ -112,6 +117,15 @@ public class LoanApplicationServiceTests {
 		assertThat(count).isEqualTo(100);
 	}
 
+	// metadata
+	@Test
+	public void shouldFailToSuccessfullyGetAllDrunksDueToTimeout() {
+		LoanApplicationService service = new LoanApplicationService(new RestTemplateBuilder().setReadTimeout(Duration.ofSeconds(1)));
+		service.setPort(this.stubPort);
+		// when:
+		BDDAssertions.thenThrownBy(service::countDrunks).hasMessageContaining("Read timed out");
+	}
+
 	@Test
 	public void shouldSuccessfullyGetCookies() {
 		// when:
@@ -124,7 +138,7 @@ public class LoanApplicationServiceTests {
 	public void shouldSuccessfullyWorkWithMultipart() {
 		// given:
 		RequestSpecification request = RestAssured.given()
-				.baseUri("http://localhost:"+ stubPort + "/")
+				.baseUri("http://localhost:" + stubPort + "/")
 				.header("Content-Type", "multipart/form-data")
 				.multiPart("file1", "filename1", "content1".getBytes())
 				.multiPart("file2", "filename1", "content2".getBytes()).multiPart("test",
@@ -153,7 +167,7 @@ public class LoanApplicationServiceTests {
 		// when:
 		ResponseEntity<byte[]> exchange = new RestTemplate()
 				.exchange(
-						RequestEntity.put(URI.create("http://localhost:"+ stubPort + "/1"))
+						RequestEntity.put(URI.create("http://localhost:" + stubPort + "/1"))
 								.header("Content-Type", "application/octet-stream")
 								.body(Files.readAllBytes(request.toPath())),
 						byte[].class);
@@ -166,4 +180,52 @@ public class LoanApplicationServiceTests {
 		assertThat(exchange.getBody()).isEqualTo(Files.readAllBytes(response.toPath()));
 	}
 
-}
+
+	@Test
+	public void shouldSuccessfullyApplyForLoanForYaml() {
+		this.service.setPrefix("yaml");
+		// given:
+		LoanApplication application = new LoanApplication(new Client("1234567890"),
+				123.123);
+		// when:
+		LoanApplicationResult loanApplication = service.loanApplication(application);
+		// then:
+		assertThat(loanApplication.getLoanApplicationStatus())
+				.isEqualTo(LoanApplicationStatus.LOAN_APPLIED);
+		assertThat(loanApplication.getRejectionReason()).isNull();
+	}
+
+	@Test
+	public void shouldBeRejectedDueToAbnormalLoanAmountForYaml() {
+		this.service.setPrefix("yaml");
+		// given:
+		LoanApplication application = new LoanApplication(new Client("1234567890"),
+				99999);
+		// when:
+		LoanApplicationResult loanApplication = service.loanApplication(application);
+		// then:
+		assertThat(loanApplication.getLoanApplicationStatus())
+				.isEqualTo(LoanApplicationStatus.LOAN_APPLICATION_REJECTED);
+		assertThat(loanApplication.getRejectionReason()).isEqualTo("Amount too high");
+	}
+
+	@Test
+	public void shouldSuccessfullyGetAllFraudsForYaml() {
+		this.service.setPrefix("yaml");
+		// when:
+		int count = service.countAllFrauds();
+		// then:
+		assertThat(count).isGreaterThanOrEqualTo(200);
+	}
+
+	// metadata
+	@Test
+	public void shouldFailToSuccessfullyGetAllDrunksDueToTimeoutForYaml() {
+		LoanApplicationService service = new LoanApplicationService(new RestTemplateBuilder().setReadTimeout(Duration.ofSeconds(1)));
+		service.setPort(this.stubPort);
+		service.setPrefix("yaml");
+		// when:
+		BDDAssertions.thenThrownBy(service::countAllFrauds).hasMessageContaining("Read timed out");
+	}
+
+}

samples/standalone/dsl/http-server/src/test/resources/contracts/fraud/shouldReturnFraudStats.groovy

@@ -35,6 +35,7 @@ import org.springframework.cloud.contract.spec.Contract
 			}
 		}
 	},
+	// tag::metadata[]
 	Contract.make {
 		request {
 			method GET()
@@ -49,5 +50,14 @@ import org.springframework.cloud.contract.spec.Contract
 				contentType("application/json")
 			}
 		}
+		metadata([wiremock: '''\
+	{
+		"response" : {
+			"fixedDelayMilliseconds": 2000
+		}
 	}
+'''
+		])
+	}
+	// end::metadata[]
 ]

samples/standalone/dsl/http-server/src/test/resources/contracts/yml/fraud/shouldReturnFraudStats.yml

@@ -1,4 +1,5 @@
 ---
+# tag::metadata[]
 name: "should count all frauds"
 request:
   method: GET
@@ -9,6 +10,14 @@ response:
     count: 200
   headers:
     Content-Type: application/json
+metadata:
+  wiremock: >
+    {
+      "response" : {
+        "fixedDelayMilliseconds": 2000
+      }
+    }
+# end::metadata[]
 ---
 request:
   method: GET

specs/spring-cloud-contract-spec-java/src/main/java/org/springframework/cloud/contract/spec/Contract.java

@@ -16,6 +16,8 @@
 
 package org.springframework.cloud.contract.spec;
 
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Objects;
 import java.util.function.Consumer;
 
@@ -95,6 +97,11 @@ public class Contract {
 	 */
 	private boolean inProgress;
 
+	/**
+	 * Mapping of metadata. Can be used for external integrations.
+	 */
+	private Map<String, Object> metadata = new HashMap<>();
+
 	public Contract() {
 
 	}
@@ -258,6 +265,14 @@ public class Contract {
 		consumer.call();
 	}
 
+	/**
+	 * Appends all entries to the existing metadata mapping.
+	 * @param map metadata to set
+	 */
+	public void metadata(Map<String, Object> map) {
+		this.metadata.putAll(map);
+	}
+
 	/**
 	 * Whether the contract should be ignored or not.
 	 */
@@ -360,6 +375,14 @@ public class Contract {
 		this.inProgress = inProgress;
 	}
 
+	public void setMetadata(Map<String, Object> metadata) {
+		this.metadata = metadata;
+	}
+
+	public Map<String, Object> getMetadata() {
+		return metadata;
+	}
+
 	@Override
 	public boolean equals(Object o) {
 		if (this == o) {
@@ -376,13 +399,14 @@ public class Contract {
 				&& Objects.equals(description, contract.description)
 				&& Objects.equals(name, contract.name)
 				&& Objects.equals(input, contract.input)
+				&& Objects.equals(metadata, contract.metadata)
 				&& Objects.equals(outputMessage, contract.outputMessage);
 	}
 
 	@Override
 	public int hashCode() {
 		return Objects.hash(priority, request, response, label, description, name, input,
-				outputMessage, ignored);
+				outputMessage, metadata, ignored);
 	}
 
 	@Override

specs/spring-cloud-contract-spec-kotlin/src/main/kotlin/org/springframework/cloud/contract/spec/ContractDsl.kt

@@ -25,115 +25,135 @@ import org.springframework.cloud.contract.spec.internal.*
 @ContractDslMarker
 class ContractDsl {
 
-    companion object {
-        fun contract(dsl: ContractDsl.() -> Unit): Contract = ContractDsl().apply(dsl).get()
-    }
+	companion object {
+		fun contract(dsl: ContractDsl.() -> Unit): Contract = ContractDsl().apply(dsl).get()
+	}
 
-    /**
-     * You can set the level of priority of this contract. If there are two contracts
-     * mapped for example to the same endpoint, then the one with greater priority should
-     * take precedence. A priority of 1 is highest and takes precedence over a priority of
-     * 2.
-     */
-    var priority: Int? = null
+	/**
+	 * You can set the level of priority of this contract. If there are two contracts
+	 * mapped for example to the same endpoint, then the one with greater priority should
+	 * take precedence. A priority of 1 is highest and takes precedence over a priority of
+	 * 2.
+	 */
+	var priority: Int? = null
 
-    /**
-     * The label by which you'll reference the contract on the message consumer side.
-     */
-    var label: String? = null
+	/**
+	 * The label by which you'll reference the contract on the message consumer side.
+	 */
+	var label: String? = null
 
-    /**
-     * Description of a contract. May be used in the documentation generation.
-     */
-    var description: String? = null
+	/**
+	 * Description of a contract. May be used in the documentation generation.
+	 */
+	var description: String? = null
 
-    /**
-     * Name of the generated test / stub. If not provided then the file name will be used.
-     * If you have multiple contracts in a single file and you don't provide this value
-     * then a prefix will be added to the file with the index number while iterating over
-     * the collection of contracts.
-     *
-     * Remember to have a unique name for every single contract. Otherwise you might
-     * generate tests that have two identical methods or you will override the stubs.
-     */
-    var name: String? = null
+	/**
+	 * Name of the generated test / stub. If not provided then the file name will be used.
+	 * If you have multiple contracts in a single file and you don't provide this value
+	 * then a prefix will be added to the file with the index number while iterating over
+	 * the collection of contracts.
+	 *
+	 * Remember to have a unique name for every single contract. Otherwise you might
+	 * generate tests that have two identical methods or you will override the stubs.
+	 */
+	var name: String? = null
 
-    /**
-     * Whether the contract should be ignored or not.
-     */
-    var ignored: Boolean = false
+	/**
+	 * Whether the contract should be ignored or not.
+	 */
+	var ignored: Boolean = false
 
-    /**
-     * Whether the contract is in progress. It's not ignored, but the feature is not yet
-     * finished. Used together with the {@code generateStubs} option.
-     */
-    var inProgress: Boolean = false
+	/**
+	 * Whether the contract is in progress. It's not ignored, but the feature is not yet
+	 * finished. Used together with the {@code generateStubs} option.
+	 */
+	var inProgress: Boolean = false
 
-    /**
-     * The HTTP request part of the contract.
-     */
-    var request: Request? = null
+	/**
+	 * The HTTP request part of the contract.
+	 */
+	var request: Request? = null
 
-    /**
-     * The HTTP response part of the contract.
-     */
-    var response: Response? = null
+	/**
+	 * The HTTP response part of the contract.
+	 */
+	var response: Response? = null
 
-    /**
-     * The input side of a messaging contract.
-     */
-    var input: Input? = null
+	/**
+	 * The input side of a messaging contract.
+	 */
+	var input: Input? = null
 
-    /**
-     * The output side of a messaging contract.
-     */
-    var outputMessage: OutputMessage? = null
+	/**
+	 * The output side of a messaging contract.
+	 */
+	var outputMessage: OutputMessage? = null
 
-    /**
-     * The HTTP request part of the contract.
-     * @param configurer lambda to configure the HTTP request
-     */
-    fun request(configurer: RequestDsl.() -> Unit) {
-        request = RequestDsl().apply(configurer).get()
-    }
+	/**
+	 * Mapping of metadata. Can be used for external integrations.
+	 */
+	var metadata: Map<String, Any> = HashMap()
 
-    /**
-     * The HTTP response part of the contract.
-     * @param configurer lambda to configure the HTTP response
-     */
-    fun response(configurer: ResponseDsl.() -> Unit) {
-        response = ResponseDsl().apply(configurer).get()
-    }
+	/**
+	 * The HTTP request part of the contract.
+	 * @param configurer lambda to configure the HTTP request
+	 */
+	fun request(configurer: RequestDsl.() -> Unit) {
+		request = RequestDsl().apply(configurer).get()
+	}
 
-    /**
-     * The input part of the contract.
-     * @param configurer lambda to configure the input message
-     */
-    fun input(configurer: InputDsl.() -> Unit) {
-        input = InputDsl().apply(configurer).get()
-    }
+	/**
+	 * The HTTP response part of the contract.
+	 * @param configurer lambda to configure the HTTP response
+	 */
+	fun response(configurer: ResponseDsl.() -> Unit) {
+		response = ResponseDsl().apply(configurer).get()
+	}
 
-    /**
-     * The output part of the contract.
-     * @param configurer lambda to configure the output message
-     */
-    fun outputMessage(configurer: OutputMessageDsl.() -> Unit) {
-        outputMessage = OutputMessageDsl().apply(configurer).get()
-    }
+	/**
+	 * The input part of the contract.
+	 * @param configurer lambda to configure the input message
+	 */
+	fun input(configurer: InputDsl.() -> Unit) {
+		input = InputDsl().apply(configurer).get()
+	}
 
-    private fun get(): Contract {
-        val contract = Contract()
-        priority?.also { contract.priority = priority }
-        label?.also { contract.label = label }
-        description?.also { contract.description = description }
-        name?.also { contract.name = name }
-        contract.ignored = ignored
-        contract.inProgress = inProgress
-        request?.also { contract.request = request }
-        response?.also { contract.response = response }
-        input?.also { contract.input = input }
-        outputMessage?.also { contract.outputMessage = outputMessage }
-        return contract
-    }
+	/**
+	 * The output part of the contract.
+	 * @param configurer lambda to configure the output message
+	 */
+	fun outputMessage(configurer: OutputMessageDsl.() -> Unit) {
+		outputMessage = OutputMessageDsl().apply(configurer).get()
+	}
+
+	/**
+	 * The metadata.
+	 * @param map metadata to set
+	 */
+	fun metadata(map: Map<String, Any>) {
+		metadata = metadata.plus(map)
+	}
+
+	/**
+	 * The metadata.
+	 * @param metadata metadata to set
+	 */
+	fun metadata(vararg metadata: Pair<String, Any>) = metadata(metadata.toMap())
+
+	private fun get(): Contract {
+		val contract = Contract()
+		priority?.also { contract.priority = priority }
+		label?.also { contract.label = label }
+		description?.also { contract.description = description }
+		name?.also { contract.name = name }
+		contract.metadata = metadata
+		contract.ignored = ignored
+		contract.inProgress = inProgress
+		request?.also { contract.request = request }
+		response?.also { contract.response = response }
+		input?.also { contract.input = input }
+		outputMessage?.also { contract.outputMessage = outputMessage }
+		return contract
+	}
 
 }

specs/spring-cloud-contract-spec-kotlin/src/test/kotlin/org/springframework/cloud/contract/spec/ContractTests.kt

@@ -305,6 +305,27 @@ then:
 		}
 	}
 
+	@Test
+	fun `should set contract metadata`() {
+		val contract =
+		// tag::metadata[]
+		contract {
+			metadata("wiremock" to """
+		{
+		  "response" : {
+			"fixedDelayMilliseconds": 2000
+		  }
+		}""")
+		}
+		// end::metadata[]
+
+		assertDoesNotThrow {
+			Contract.assertContract(contract)
+		}.also {
+			assertThat(contract.metadata).isNotEmpty
+		}
+	}
+
 	@Test
 	fun `should make equals and hashcode work properly for URL`() {
 		val a: Contract = contract {

spring-cloud-contract-stub-runner/src/main/java/org/springframework/cloud/contract/stubrunner/StubRunnerExecutor.java

@@ -32,6 +32,7 @@ import groovy.json.JsonOutput;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
+import org.springframework.beans.BeanUtils;
 import org.springframework.cloud.contract.spec.Contract;
 import org.springframework.cloud.contract.spec.internal.DslProperty;
 import org.springframework.cloud.contract.spec.internal.Headers;
@@ -86,15 +87,9 @@ class StubRunnerExecutor implements StubFinder {
 			}
 			return runningStubs();
 		}
-		try {
-			HttpServerStubConfigurer configurer = stubRunnerOptions
-					.getHttpServerStubConfigurer().newInstance();
-			startStubServers(configurer, stubRunnerOptions, stubConfiguration,
-					repository);
-		}
-		catch (InstantiationException | IllegalAccessException ex) {
-			log.error("Failed to instantiate the HTTP stub configurer", ex);
-		}
+		HttpServerStubConfigurer configurer = BeanUtils
+				.instantiateClass(stubRunnerOptions.getHttpServerStubConfigurer());
+		startStubServers(configurer, stubRunnerOptions, stubConfiguration, repository);
 		RunningStubs runningCollaborators = runningStubs();
 		log.info("All stubs are now running " + runningCollaborators.toString());
 		return runningCollaborators;

spring-cloud-contract-tools/spring-cloud-contract-converters/src/main/java/org/springframework/cloud/contract/verifier/converter/StubGenerator.java

@@ -16,7 +16,9 @@
 
 package org.springframework.cloud.contract.verifier.converter;
 
+import java.util.List;
 import java.util.Map;
+import java.util.stream.Collectors;
 
 import org.springframework.cloud.contract.spec.Contract;
 import org.springframework.cloud.contract.verifier.file.ContractMetadata;
@@ -24,9 +26,10 @@ import org.springframework.cloud.contract.verifier.file.ContractMetadata;
 /**
  * Converts contracts into their stub representation.
  *
+ * @param <T> - type of stub mapping
  * @since 1.1.0
  */
-public interface StubGenerator {
+public interface StubGenerator<T> {
 
 	/**
 	 * @param fileName - file name
@@ -45,6 +48,35 @@ public interface StubGenerator {
 	 */
 	Map<Contract, String> convertContents(String rootName, ContractMetadata content);
 
+	/**
+	 * Post process a generated stub mapping.
+	 * @param stubMapping - mapping of a stub
+	 * @param contract - contract for which stub was generated
+	 * @return the converted stub mapping
+	 */
+	default T postProcessStubMapping(T stubMapping, Contract contract) {
+		List<StubPostProcessor> processors = StubPostProcessor.PROCESSORS.stream()
+				.filter(p -> p.isApplicable(contract)).collect(Collectors.toList());
+		if (processors.isEmpty()) {
+			return defaultStubMappingPostProcessing(stubMapping, contract);
+		}
+		T stub = stubMapping;
+		for (StubPostProcessor processor : processors) {
+			stub = (T) processor.postProcess(stub, contract);
+		}
+		return stub;
+	}
+
+	/**
+	 * Stub mapping to chose when no post processors where found on the classpath.
+	 * @param stubMapping - mapping of a stub
+	 * @param contract - contract for which stub was generated
+	 * @return the converted stub mapping
+	 */
+	default T defaultStubMappingPostProcessing(T stubMapping, Contract contract) {
+		return stubMapping;
+	}
+
 	/**
 	 * @param inputFileName - name of the input file
 	 * @return the name of the converted stub file. If you have multiple contracts in a

spring-cloud-contract-tools/spring-cloud-contract-converters/src/main/java/org/springframework/cloud/contract/verifier/converter/StubPostProcessor.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2013-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.contract.verifier.converter;
+
+import java.util.List;
+
+import org.springframework.cloud.contract.spec.Contract;
+import org.springframework.core.io.support.SpringFactoriesLoader;
+
+/**
+ * Post processor of stub mappings.
+ *
+ * @param <T> type of stub mapping
+ * @author Marcin Grzejszczak
+ * @since 3.0.0
+ */
+public interface StubPostProcessor<T> {
+
+	/**
+	 * List of registered stub post processors.
+	 */
+	List<StubPostProcessor> PROCESSORS = SpringFactoriesLoader
+			.loadFactories(StubPostProcessor.class, null);
+
+	/**
+	 * @param stubMapping - generated stub mapping
+	 * @param contract - contract for which the mapping was generated
+	 * @return modified stub mapping
+	 */
+	default T postProcess(T stubMapping, Contract contract) {
+		return stubMapping;
+	}
+
+	/**
+	 * @param contract - contract for which the mapping was generated
+	 * @return {@code true} if this post process should be applied
+	 */
+	boolean isApplicable(Contract contract);
+
+}

spring-cloud-contract-tools/spring-cloud-contract-converters/src/main/java/org/springframework/cloud/contract/verifier/wiremock/DefaultWireMockStubPostProcessor.java

@@ -0,0 +1,188 @@
+/*
+ * Copyright 2013-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.contract.verifier.wiremock;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.github.tomakehurst.wiremock.common.Metadata;
+import com.github.tomakehurst.wiremock.extension.Parameters;
+import com.github.tomakehurst.wiremock.http.ChunkedDribbleDelay;
+import com.github.tomakehurst.wiremock.http.DelayDistribution;
+import com.github.tomakehurst.wiremock.http.Fault;
+import com.github.tomakehurst.wiremock.http.ResponseDefinition;
+import com.github.tomakehurst.wiremock.stubbing.StubMapping;
+
+import org.springframework.cloud.contract.spec.Contract;
+
+class DefaultWireMockStubPostProcessor implements WireMockStubPostProcessor {
+
+	private static final List<Class> APPLICABLE_CLASSES = Arrays.asList(String.class,
+			StubMapping.class, Map.class);
+
+	public static final String WIREMOCK_METADATA_ENTRY = "wiremock";
+
+	private final ObjectMapper objectMapper = new ObjectMapper();
+
+	@Override
+	public StubMapping postProcess(StubMapping stubMapping, Contract contract) {
+		Object wiremock = getWiremockEntry(contract);
+		StubMapping stubMappingFromMetadata = stubMappingFromMetadata(wiremock);
+		stubMapping.setResponse(mergedResponse(stubMapping, stubMappingFromMetadata));
+		if (stubMappingFromMetadata.getPostServeActions() != null) {
+			setPostServeActions(stubMapping, stubMappingFromMetadata);
+		}
+		if (stubMappingFromMetadata.getMetadata() != null) {
+			setMetadata(stubMapping, stubMappingFromMetadata);
+		}
+		return stubMapping;
+	}
+
+	public void setPostServeActions(StubMapping stubMapping,
+			StubMapping stubMappingFromMetadata) {
+		Map<String, Parameters> postServeActions = stubMapping.getPostServeActions();
+		postServeActions = postServeActions != null ? postServeActions : new HashMap<>();
+		postServeActions.putAll(stubMappingFromMetadata.getPostServeActions());
+		stubMapping.setPostServeActions(postServeActions);
+	}
+
+	public void setMetadata(StubMapping stubMapping,
+			StubMapping stubMappingFromMetadata) {
+		Metadata metadata = stubMapping.getMetadata();
+		metadata = metadata != null ? metadata : new Metadata();
+		metadata.putAll(stubMappingFromMetadata.getPostServeActions());
+		stubMapping.setMetadata(metadata);
+	}
+
+	public ResponseDefinition mergedResponse(StubMapping stubMapping,
+			StubMapping stubMappingFromMetadata) {
+		ResponseDefinition responseDefinition = new ResponseDefinition(
+				stubMapping.getResponse().getStatus(),
+				stubMapping.getResponse().getStatusMessage(),
+				stubMapping.getResponse().getBody(),
+				stubMapping.getResponse().getJsonBody(),
+				stubMapping.getResponse().getBase64Body(),
+				stubMapping.getResponse().getBodyFileName(),
+				stubMapping.getResponse().getHeaders(),
+				stubMapping.getResponse().getAdditionalProxyRequestHeaders(),
+				fixedDelayMilliseconds(stubMapping, stubMappingFromMetadata),
+				delayDistribution(stubMapping, stubMappingFromMetadata),
+				chunkedDribbleDelay(stubMapping, stubMappingFromMetadata),
+				proxyBaseUrl(stubMapping, stubMappingFromMetadata),
+				fault(stubMapping, stubMappingFromMetadata),
+				transformers(stubMapping, stubMappingFromMetadata),
+				transformerParameters(stubMapping, stubMappingFromMetadata),
+				wasConfigured(stubMapping, stubMappingFromMetadata));
+		return responseDefinition;
+	}
+
+	public Boolean wasConfigured(StubMapping stubMapping,
+			StubMapping stubMappingFromMetadata) {
+		return stubMappingFromMetadata.getResponse().isFromConfiguredStub() != null
+				? stubMappingFromMetadata.getResponse().isFromConfiguredStub()
+				: stubMapping.getResponse().isFromConfiguredStub();
+	}
+
+	public Parameters transformerParameters(StubMapping stubMapping,
+			StubMapping stubMappingFromMetadata) {
+		return stubMappingFromMetadata.getResponse().getTransformerParameters() != null
+				? stubMappingFromMetadata.getResponse().getTransformerParameters()
+				: stubMapping.getResponse().getTransformerParameters();
+	}
+
+	public List<String> transformers(StubMapping stubMapping,
+			StubMapping stubMappingFromMetadata) {
+		return stubMappingFromMetadata.getResponse().getTransformers() != null
+				? stubMappingFromMetadata.getResponse().getTransformers()
+				: stubMapping.getResponse().getTransformers();
+	}
+
+	public Fault fault(StubMapping stubMapping, StubMapping stubMappingFromMetadata) {
+		return stubMappingFromMetadata.getResponse().getFault() != null
+				? stubMappingFromMetadata.getResponse().getFault()
+				: stubMapping.getResponse().getFault();
+	}
+
+	public String proxyBaseUrl(StubMapping stubMapping,
+			StubMapping stubMappingFromMetadata) {
+		return stubMappingFromMetadata.getResponse().getProxyBaseUrl() != null
+				? stubMappingFromMetadata.getResponse().getProxyBaseUrl()
+				: stubMapping.getResponse().getProxyBaseUrl();
+	}
+
+	public ChunkedDribbleDelay chunkedDribbleDelay(StubMapping stubMapping,
+			StubMapping stubMappingFromMetadata) {
+		return stubMappingFromMetadata.getResponse().getChunkedDribbleDelay() != null
+				? stubMappingFromMetadata.getResponse().getChunkedDribbleDelay()
+				: stubMapping.getResponse().getChunkedDribbleDelay();
+	}
+
+	public DelayDistribution delayDistribution(StubMapping stubMapping,
+			StubMapping stubMappingFromMetadata) {
+		return stubMappingFromMetadata.getResponse().getDelayDistribution() != null
+				? stubMappingFromMetadata.getResponse().getDelayDistribution()
+				: stubMapping.getResponse().getDelayDistribution();
+	}
+
+	public Integer fixedDelayMilliseconds(StubMapping stubMapping,
+			StubMapping stubMappingFromMetadata) {
+		return stubMappingFromMetadata.getResponse().getFixedDelayMilliseconds() != null
+				? stubMappingFromMetadata.getResponse().getFixedDelayMilliseconds()
+				: stubMapping.getResponse().getFixedDelayMilliseconds();
+	}
+
+	private Object getWiremockEntry(Contract contract) {
+		return contract.getMetadata().get(WIREMOCK_METADATA_ENTRY);
+	}
+
+	private StubMapping stubMappingFromMetadata(Object wiremock) {
+		if (wiremock instanceof String) {
+			return StubMapping.buildFrom((String) wiremock);
+		}
+		else if (wiremock instanceof StubMapping) {
+			return (StubMapping) wiremock;
+		}
+		else if (wiremock instanceof Map) {
+			try {
+				return StubMapping
+						.buildFrom(this.objectMapper.writeValueAsString(wiremock));
+			}
+			catch (JsonProcessingException e) {
+				throw new IllegalStateException(
+						"Failed to build StubMapping for map [" + wiremock + "]", e);
+			}
+		}
+		throw new UnsupportedOperationException(
+				"Unsupported type for wiremock metadata extension");
+	}
+
+	@Override
+	public boolean isApplicable(Contract contract) {
+		boolean contains = contract.getMetadata().containsKey(WIREMOCK_METADATA_ENTRY);
+		if (!contains) {
+			return false;
+		}
+		Object wiremock = getWiremockEntry(contract);
+		return APPLICABLE_CLASSES.stream()
+				.anyMatch(aClass -> aClass.isAssignableFrom(wiremock.getClass()));
+	}
+
+}

spring-cloud-contract-tools/spring-cloud-contract-converters/src/main/java/org/springframework/cloud/contract/verifier/wiremock/DslToWireMockClientConverter.java

@@ -24,6 +24,8 @@ import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.stream.Collectors;
 
+import com.github.tomakehurst.wiremock.stubbing.StubMapping;
+
 import org.springframework.cloud.contract.spec.Contract;
 import org.springframework.cloud.contract.verifier.dsl.wiremock.WireMockStubStrategy;
 import org.springframework.cloud.contract.verifier.file.ContractMetadata;
@@ -39,7 +41,31 @@ public class DslToWireMockClientConverter extends DslToWireMockConverter {
 
 	private String convertASingleContract(String rootName, ContractMetadata contract,
 			Contract dsl) {
-		return new WireMockStubStrategy(rootName, contract, dsl).toWireMockClientStub();
+		StubMapping stubMapping = new WireMockStubStrategy(rootName, contract, dsl)
+				.toWireMockClientStub();
+		StubMapping mapping = postProcessStubMapping(stubMapping, dsl);
+		if (mapping == null) {
+			return "";
+		}
+		return mapping.toString();
+	}
+
+	@Override
+	public StubMapping postProcessStubMapping(StubMapping stubMapping,
+			Contract contract) {
+		StubMapping mapping = super.postProcessStubMapping(stubMapping, contract);
+		// apply the default WireMock processor as the last one
+		return defaultStubMappingPostProcessing(mapping, contract);
+	}
+
+	@Override
+	public StubMapping defaultStubMappingPostProcessing(StubMapping stubMapping,
+			Contract contract) {
+		DefaultWireMockStubPostProcessor processor = new DefaultWireMockStubPostProcessor();
+		if (processor.isApplicable(contract)) {
+			return processor.postProcess(stubMapping, contract);
+		}
+		return stubMapping;
 	}
 
 	@Override

spring-cloud-contract-tools/spring-cloud-contract-converters/src/main/java/org/springframework/cloud/contract/verifier/wiremock/DslToWireMockConverter.java

@@ -16,6 +16,8 @@
 
 package org.springframework.cloud.contract.verifier.wiremock;
 
+import com.github.tomakehurst.wiremock.stubbing.StubMapping;
+
 import org.springframework.cloud.contract.verifier.converter.StubGenerator;
 
 /**
@@ -23,7 +25,7 @@ import org.springframework.cloud.contract.verifier.converter.StubGenerator;
  *
  * @since 1.0.0
  */
-public abstract class DslToWireMockConverter implements StubGenerator {
+public abstract class DslToWireMockConverter implements StubGenerator<StubMapping> {
 
 	@Override
 	public String generateOutputFileNameForInput(String inputFileName) {

spring-cloud-contract-tools/spring-cloud-contract-converters/src/main/java/org/springframework/cloud/contract/verifier/wiremock/WireMockStubPostProcessor.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2013-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.contract.verifier.wiremock;
+
+import com.github.tomakehurst.wiremock.stubbing.StubMapping;
+
+import org.springframework.cloud.contract.verifier.converter.StubPostProcessor;
+
+/**
+ * Post processor of WireMock stub mappings.
+ *
+ * @author Marcin Grzejszczak
+ * @since 3.0.0
+ */
+public interface WireMockStubPostProcessor extends StubPostProcessor<StubMapping> {
+
+}

spring-cloud-contract-tools/spring-cloud-contract-converters/src/test/java/org/springframework/cloud/contract/verifier/wiremock/DefaultWireMockStubPostProcessorTests.java

@@ -0,0 +1,153 @@
+/*
+ * Copyright 2013-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.contract.verifier.wiremock;
+
+import java.util.HashMap;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.github.tomakehurst.wiremock.extension.Parameters;
+import com.github.tomakehurst.wiremock.stubbing.StubMapping;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.cloud.contract.spec.Contract;
+
+import static org.assertj.core.api.BDDAssertions.then;
+
+class DefaultWireMockStubPostProcessorTests {
+
+	// @formatter:off
+	private static final String STUB_MAPPING = "{\n" + "    \"request\": {\n"
+			+ "        \"method\": \"GET\",\n" + "        \"url\": \"/ping\"\n"
+			+ "    },\n" + "    \"response\": {\n" + "        \"status\": 200,\n"
+			+ "        \"body\": \"pong\",\n" + "        \"headers\": {\n"
+			+ "            \"Content-Type\": \"text/plain\"\n" + "        }\n" + "    }\n"
+			+ "}";
+
+	private static final String POST_SERVE_ACTION = "{ \"postServeActions\": {\n"
+			+ "      \"webhook\": {\n" + "        \"headers\": {\n"
+			+ "          \"Content-Type\": \"application/json\"\n" + "        },\n"
+			+ "        \"method\": \"POST\",\n"
+			+ "        \"body\": \"{ \\\"result\\\": \\\"SUCCESS\\\" }\",\n"
+			+ "        \"url\": \"http://localhost:56299/callback\"\n" + "      }\n"
+			+ "    } }";
+
+	private static final String RESPONSE_DELAY = "{\n"
+			+ "    \"response\": {\n"
+			+ "            \"delayDistribution\": {\n"
+			+ "                    \"type\": \"lognormal\",\n"
+			+ "                    \"median\": 80,\n"
+			+ "                    \"sigma\": 0.4\n"
+			+ "            }\n"
+			+ "    }\n"
+			+ "}\n";
+	// @formatter:on
+
+	@Test
+	void should_not_be_applicable_for_missing_metadata_entry() {
+		then(new DefaultWireMockStubPostProcessor().isApplicable(new Contract()))
+				.isFalse();
+	}
+
+	@Test
+	void should_not_be_applicable_for_invalid_metadata_entry() {
+		Contract contract = new Contract();
+		contract.getMetadata().put("wiremock", 5);
+
+		then(new DefaultWireMockStubPostProcessor().isApplicable(contract)).isFalse();
+	}
+
+	@Test
+	void should_be_applicable_for_valid_metadata_entry() {
+		Contract contract = new Contract();
+		contract.getMetadata().put("wiremock", "foo");
+
+		then(new DefaultWireMockStubPostProcessor().isApplicable(contract)).isTrue();
+
+		contract.getMetadata().put("wiremock", new StubMapping());
+
+		then(new DefaultWireMockStubPostProcessor().isApplicable(contract)).isTrue();
+
+		contract.getMetadata().put("wiremock", new HashMap<>());
+
+		then(new DefaultWireMockStubPostProcessor().isApplicable(contract)).isTrue();
+	}
+
+	@Test
+	void should_merge_stub_mappings_when_stub_mapping_is_string() {
+		Contract contract = new Contract();
+		contract.getMetadata().put("wiremock", POST_SERVE_ACTION);
+		StubMapping stubMapping = StubMapping.buildFrom(STUB_MAPPING);
+
+		StubMapping result = new DefaultWireMockStubPostProcessor()
+				.postProcess(stubMapping, contract);
+
+		thenPostServerActionWasSet(result);
+	}
+
+	@Test
+	void should_merge_stub_mappings_when_stub_mapping_is_stub_mapping() {
+		Contract contract = new Contract();
+		contract.getMetadata().put("wiremock", StubMapping.buildFrom(POST_SERVE_ACTION));
+		StubMapping stubMapping = StubMapping.buildFrom(STUB_MAPPING);
+
+		StubMapping result = new DefaultWireMockStubPostProcessor()
+				.postProcess(stubMapping, contract);
+
+		thenPostServerActionWasSet(result);
+	}
+
+	@Test
+	void should_merge_stub_mappings_when_stub_mapping_is_map()
+			throws JsonProcessingException {
+		Contract contract = new Contract();
+		contract.getMetadata().put("wiremock",
+				new ObjectMapper().readValue(POST_SERVE_ACTION, HashMap.class));
+		StubMapping stubMapping = StubMapping.buildFrom(STUB_MAPPING);
+
+		StubMapping result = new DefaultWireMockStubPostProcessor()
+				.postProcess(stubMapping, contract);
+
+		thenPostServerActionWasSet(result);
+	}
+
+	@Test
+	void should_merge_stub_mappings_when_stub_mapping_is_string_and_contains_response() {
+		Contract contract = new Contract();
+		contract.getMetadata().put("wiremock", RESPONSE_DELAY);
+		StubMapping stubMapping = StubMapping.buildFrom(STUB_MAPPING);
+
+		StubMapping result = new DefaultWireMockStubPostProcessor()
+				.postProcess(stubMapping, contract);
+
+		then(result.getRequest().getMethod().getName()).isEqualTo("GET");
+		then(result.getResponse().getStatus()).isEqualTo(200);
+		then(result.getResponse().getBody()).isEqualTo("pong");
+		then(result.getResponse().getHeaders().size()).isEqualTo(1);
+		then(result.getResponse().getDelayDistribution()).isNotNull();
+	}
+
+	private void thenPostServerActionWasSet(StubMapping result) {
+		then(result.getRequest().getMethod().getName()).isEqualTo("GET");
+		then(result.getResponse().getStatus()).isEqualTo(200);
+		then(result.getResponse().getBody()).isEqualTo("pong");
+		then(result.getPostServeActions()).containsKey("webhook");
+		Parameters webhook = result.getPostServeActions().get("webhook");
+		then(webhook.getString("method")).isEqualTo("POST");
+	}
+
+}

spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/converter/ContractsToYaml.groovy

@@ -61,6 +61,7 @@ class ContractsToYaml {
 			yamlContract.inProgress = contract.inProgress
 			yamlContract.description = contract.description
 			yamlContract.label = contract.label
+			yamlContract.metadata = contract.metadata
 			request(contract, yamlContract)
 			response(yamlContract, contract)
 			input(contract, yamlContract)

spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/converter/YamlContract.java

@@ -54,6 +54,8 @@ public class YamlContract {
 
 	public boolean inProgress;
 
+	public Map<String, Object> metadata;
+
 	public static class Request {
 
 		public String method;

spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/converter/YamlToContracts.groovy

@@ -102,6 +102,9 @@ class YamlToContracts {
 				if (yamlContract.inProgress) {
 					inProgress()
 				}
+				if (yamlContract.metadata) {
+					metadata(yamlContract.metadata)
+				}
 				if (yamlContract.request?.method) {
 					request {
 						method(yamlContract.request?.method)

spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/dsl/wiremock/WireMockStubStrategy.groovy

@@ -51,9 +51,9 @@ class WireMockStubStrategy {
 	}
 
 	/**
-	 * Converts {@link ContractMetadata} to String version of {@link StubMapping}
+	 * Converts {@link ContractMetadata} to {@link StubMapping}
 	 */
-	String toWireMockClientStub() {
+	StubMapping toWireMockClientStub() {
 		StubMapping stubMapping = new StubMapping()
 		RequestPattern request = wireMockRequestStubStrategy.buildClientRequestContent()
 		ResponseDefinition response = wireMockResponseStubStrategy.
@@ -66,11 +66,11 @@ class WireMockStubStrategy {
 		stubMapping.response = response
 
 		if (!request || !response) {
-			return ''
+			return null
 		}
 
 		if (groovyDsl.ignored || contract.ignored) {
-			return ''
+			return null
 		}
 
 		if (contract.order != null) {
@@ -80,6 +80,6 @@ class WireMockStubStrategy {
 				stubMapping.newScenarioState = STEP_PREFIX + (contract.order + 1)
 			}
 		}
-		return StubMapping.buildJsonStringFor(stubMapping)
+		return stubMapping
 	}
 }

spring-cloud-contract-verifier/src/test/groovy/org/springframework/cloud/contract/verifier/converter/YamlContractConverterSpec.groovy

@@ -714,6 +714,7 @@ name: "post1"
 priority: null
 ignored: false
 inProgress: false
+metadata: null
 '''
 			String expectedYaml2 = '''\
 ---
@@ -756,6 +757,7 @@ name: "post2"
 priority: null
 ignored: false
 inProgress: false
+metadata: null
 '''
 		when:
 			Map<String, byte[]> strings = converter.store([

spring-cloud-contract-verifier/src/test/groovy/org/springframework/cloud/contract/verifier/dsl/wiremock/WireMockGroovyDslSpec.groovy

@@ -19,6 +19,7 @@ package org.springframework.cloud.contract.verifier.dsl.wiremock
 import com.github.tomakehurst.wiremock.WireMockServer
 import com.github.tomakehurst.wiremock.core.WireMockConfiguration
 import com.github.tomakehurst.wiremock.extension.responsetemplating.ResponseTemplateTransformer
+import com.github.tomakehurst.wiremock.stubbing.StubMapping
 import groovy.json.JsonBuilder
 import groovy.json.JsonOutput
 import groovy.json.JsonSlurper
@@ -2003,7 +2004,7 @@ class WireMockGroovyDslSpec extends Specification implements WireMockStubVerifie
 		when:
 			def json = toWireMockClientJsonStub(groovyDsl)
 		then:
-			json == ''
+			json == null
 	}
 
 	@Issue('#30')
@@ -2031,7 +2032,7 @@ class WireMockGroovyDslSpec extends Specification implements WireMockStubVerifie
 			def json = new WireMockStubStrategy("Test", new ContractMetadata(null, true, 0, null, groovyDsl), groovyDsl).
 					toWireMockClientStub()
 		then:
-			json == ''
+			json == null
 	}
 
 	@Issue('#237')
@@ -2982,7 +2983,7 @@ class WireMockGroovyDslSpec extends Specification implements WireMockStubVerifie
 				}
 			}
 		and:
-			String wireMockStub = new WireMockStubStrategy("Test",
+			StubMapping wireMockStub = new WireMockStubStrategy("Test",
 					new ContractMetadata(null, false, 0, null, contractDsl), contractDsl)
 					.toWireMockClientStub()
 
@@ -2992,7 +2993,7 @@ class WireMockGroovyDslSpec extends Specification implements WireMockStubVerifie
 			server.start()
 		and:
 			stubMappingIsValidWireMockStub(wireMockStub)
-			server.addStubMapping(WireMockStubMapping.buildFrom(wireMockStub))
+			server.addStubMapping(wireMockStub)
 		when:
 			ResponseEntity<String> entity = callWithOptionalAndEmpty(port)
 		then:

spring-cloud-contract-verifier/src/test/groovy/org/springframework/cloud/contract/verifier/dsl/wiremock/WireMockStubVerifier.groovy

@@ -28,11 +28,16 @@ trait WireMockStubVerifier {
 
 	void stubMappingIsValidWireMockStub(String mappingDefinition) {
 		StubMapping stubMapping = WireMockStubMapping.buildFrom(mappingDefinition)
-		stubMapping.request.bodyPatterns.findAll { it.isPresent() && it instanceof RegexPattern }.every {
+		stubMappingIsValidWireMockStub(stubMapping)
+	}
+	
+	void stubMappingIsValidWireMockStub(StubMapping mappingDefinition) {
+		mappingDefinition.request.bodyPatterns.findAll { it.isPresent() && it instanceof RegexPattern }.every {
 			Pattern.compile(it.getValue())
 		}
-		assert !mappingDefinition.contains('org.springframework.cloud.contract.spec.internal')
-		assert !mappingDefinition.contains('cursor')
+		String definition = mappingDefinition.toString()
+		assert !definition.contains('org.springframework.cloud.contract.spec.internal')
+		assert !definition.contains('cursor')
 	}
 
 	void stubMappingIsValidWireMockStub(Contract contractDsl) {

spring-cloud-contract-verifier/src/test/resources/contractsToCompile/contract_rest_with_tags.java

@@ -16,8 +16,11 @@
  */
 
 // tag::class[]
+
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.function.Supplier;
 
 import org.springframework.cloud.contract.spec.Contract;
@@ -58,6 +61,16 @@ class contract_rest_with_tags implements Supplier<Collection<Contract>> {
 
 	// end::in_progress[]
 
+	static Object metadata = Collections.singletonList(
+			// tag::metadata[]
+			Contract.make(c -> {
+				Map<String, Object> map = new HashMap<>();
+				map.put("wiremock", "{ \"response\" : { \"fixedDelayMilliseconds\" : 2000 } }");
+				c.metadata(map);
+			}));
+
+	// end::metadata[]
+
 	@Override
 	public Collection<Contract> get() {
 		return Collections.singletonList(Contract.make(c -> {