This version is still in development and is not considered stable yet. For the latest stable version, please use spring-cloud-contract 4.1.4! |
WireMock Customization
In this section, we show how to customize the way you work with WireMock.
Registering Your Own WireMock Extension
WireMock lets you register custom extensions. By default, Spring Cloud Contract registers
the transformer, which lets you reference a request from a response. If you want to
provide your own extensions, you can register an implementation of the
org.springframework.cloud.contract.verifier.dsl.wiremock.WireMockExtensions
interface.
Since we use the spring.factories
extension approach, you can create an entry similar to
the following in the META-INF/spring.factories
file:
org.springframework.cloud.contract.verifier.dsl.wiremock.WireMockExtensions=\
org.springframework.cloud.contract.stubrunner.provider.wiremock.TestWireMockExtensions
org.springframework.cloud.contract.spec.ContractConverter=\
org.springframework.cloud.contract.stubrunner.TestCustomYamlContractConverter
The following example shows a custom extension:
import com.github.tomakehurst.wiremock.extension.Extension
/**
* Extension that registers the default transformer and the custom one
*/
class TestWireMockExtensions implements WireMockExtensions {
@Override
List<Extension> extensions() {
return [
new DefaultResponseTransformer(),
new CustomExtension()
]
}
}
class CustomExtension implements Extension {
@Override
String getName() {
return "foo-transformer"
}
}
If you want the transformation to be applied only for a mapping that explicitly
requires it, override the applyGlobally() method and set it to false .
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Customization of WireMock Configuration
You can register a bean of type org.springframework.cloud.contract.wiremock.WireMockConfigurationCustomizer
to customize the WireMock configuration (for example, to add custom transformers).
The following example shows how to do so:
@Bean
WireMockConfigurationCustomizer optionsCustomizer() {
return new WireMockConfigurationCustomizer() {
@Override
public void customize(WireMockConfiguration options) {
// perform your customization here
}
};
}
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
name: "should count all frauds"
request:
method: GET
url: /yamlfrauds
response:
status: 200
body:
count: 200
headers:
Content-Type: application/json
metadata:
wiremock:
stubMapping: >
{
"response" : {
"fixedDelayMilliseconds": 2000
}
}
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.
{
"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 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.
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.
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