弹簧云合同:在URL生成的合同响应中访问主机名和端口

Question

我们试图提供以下特征的合同：

import org.springframework.cloud.contract.spec.Contract
Contract.make {
    request {
        method(GET())
        url("/v2/entity")
        headers {
            accept(applicationJson())
        }
    }
    response {
        status 200
        body( """
         {
            "saveLink": "http://<requestedHost>:<requestedPort>/v2/entity/save"
          }
        )
    }
}

如果我们的客户使用Stubrunner并选择了另一个端口，则E.Q。9876，" savelink"应在响应URL中反映出此端口。我们无法找到一种简单的API来获取主机和端口信息。FromRequest（）或URL（）仅返回请求URL的相对部分。是否有API方法或该要求的简单解决方案？还有其他建议吗？

Answer 1

首先，我认为您正在误解合同测试的概念。我想知道为什么在那里拥有那些具体的值对您来说至关重要？在合同测试中，您只对链接包含URL和端口的某些值感兴趣。您甚至都不会打电话给该网址。因此，很可能您应该在进行进一步之前改变方法。

但是，如果您决定这是唯一的方法，我就对您如何解决这个问题提出了我的看法（尽管我尚未测试它，但看起来它应该起作用；））。

）。

当前使所有工作都不容易。此https://github.com/spring-cloud/spring-cloud-contract/pull/429合并后，在即将发布的EDGware版本中会更容易。

不过，我会尝试考虑解决方法。我们要做的是添加一种转换机制，该机制将在从WireMock发送回响应有效载荷之前修改响应有效载荷。我们将需要转换类，我们也需要扩展现有的存根机制。

首先，让我们创建一个自定义的WireMock扩展程序，该扩展名将分析WireMock消耗的每个映射。我们将只需要修改其中包含saveLink的一个。

class CustomExtension extends ResponseTransformer {
    @Override
    String getName() {
        return "url-transformer";
    }
    /**
     * Transformer that converts the save the way we want it to look like
     */
    @Override
    Response transform(Request request, Response response, FileSource files, Parameters parameters) {
    if (requestRelatedToMyParticularCase(response)) {
      String body = ""{"saveLink" : "http://"+ url.host + ":" + url.port + "/v2/entity/save"}"";
      return new Response(response.getStatus(), response.getStatusMessage(),
                body, response.getHeaders(), response.wasConfigured(), response.getFault(), response.isFromProxy());
    }
    // if it's not related continue as usual
        return response;
    }
  private boolean requestRelatedToMyParticularCase(Response response) {
    // is it related to your particular scenario ?
    return response.bodyAsString.contains("saveLink");
  }
    /**
     * We want to apply this transformation for all mappings
     */
    @Override
    boolean applyGlobally() {
        return true
    }
}

现在，您可以创建一个实现HttpServerStub的类，并按照此处介绍的方式注册-http：//cloud.spring.io/spring-cloud-cloud-static/dalston.sr3/#_custom_stub_runner。它基本上是WireMockHttpServerStub的副本，并具有更改，我们可以手动添加变压器

public class MyCustomWireMockHttpServerStub implements HttpServerStub {
    private static final Logger log = LoggerFactory.getLogger(MyCustomWireMockHttpServerStub.class);
    private static final int INVALID_PORT = -1;
    private WireMockServer wireMockServer;
  @Override
    public HttpServerStub start(int port) {
        this.wireMockServer = new WireMockServer(myConfig().port(port)
                .notifier(new Slf4jNotifier(true)));
        this.wireMockServer.start();
        return this;
    }
    private WireMockConfiguration myConfig() {
        if (ClassUtils.isPresent("org.springframework.cloud.contract.wiremock.WireMockSpring", null)) {
            return WireMockSpring.options()
                    .extensions(responseTransformers());
        }
        return new WireMockConfiguration().extensions(responseTransformers());
    }
    private Extension[] responseTransformers() {
      List<Extension> extensions = new ArrayList<>();
      extensions.add(defaultResponseTemplateTransformer());
      extensions.add(new CustomExtension());
      return extensions.toArray(new Extension[extensions.size()]);
    }
    private ResponseTemplateTransformer defaultResponseTemplateTransformer() {
        return new ResponseTemplateTransformer(false, helpers());
    }
    @Override
    public int port() {
        return isRunning() ? this.wireMockServer.port() : INVALID_PORT;
    }
    @Override
    public boolean isRunning() {
        return this.wireMockServer != null && this.wireMockServer.isRunning();
    }
    @Override
    public HttpServerStub start() {
        if (isRunning()) {
            if (log.isDebugEnabled()) {
                log.debug("The server is already running at port [" + port() + "]");
            }
            return this;
        }
        return start(SocketUtils.findAvailableTcpPort());
    }
    @Override
    public HttpServerStub stop() {
        if (!isRunning()) {
            if (log.isDebugEnabled()) {
                log.debug("Trying to stop a non started server!");
            }
            return this;
        }
        this.wireMockServer.stop();
        return this;
    }
    @Override
    public HttpServerStub registerMappings(Collection<File> stubFiles) {
        if (!isRunning()) {
            throw new IllegalStateException("Server not started!");
        }
        registerStubMappings(stubFiles);
        return this;
    }
    @Override public String registeredMappings() {
        Collection<String> mappings = new ArrayList<>();
        for (StubMapping stubMapping : this.wireMockServer.getStubMappings()) {
            mappings.add(stubMapping.toString());
        }
        return jsonArrayOfMappings(mappings);
    }
    private String jsonArrayOfMappings(Collection<String> mappings) {
        return "[" + StringUtils.collectionToDelimitedString(mappings, ",n") + "]";
    }
    @Override
    public boolean isAccepted(File file) {
        return file.getName().endsWith(".json");
    }
    StubMapping getMapping(File file) {
        try (InputStream stream = Files.newInputStream(file.toPath())) {
            return StubMapping.buildFrom(
                    StreamUtils.copyToString(stream, Charset.forName("UTF-8")));
        }
        catch (IOException e) {
            throw new IllegalStateException("Cannot read file", e);
        }
    }
    private void registerStubMappings(Collection<File> stubFiles) {
        WireMock wireMock = new WireMock("localhost", port(), "");
        registerDefaultHealthChecks(wireMock);
        registerStubs(stubFiles, wireMock);
    }
    private void registerDefaultHealthChecks(WireMock wireMock) {
        registerHealthCheck(wireMock, "/ping");
        registerHealthCheck(wireMock, "/health");
    }
    private void registerStubs(Collection<File> sortedMappings, WireMock wireMock) {
        for (File mappingDescriptor : sortedMappings) {
            try {
                wireMock.register(getMapping(mappingDescriptor));
                if (log.isDebugEnabled()) {
                    log.debug("Registered stub mappings from [" + mappingDescriptor + "]");
                }
            }
            catch (Exception e) {
                if (log.isDebugEnabled()) {
                    log.debug("Failed to register the stub mapping [" + mappingDescriptor + "]", e);
                }
            }
        }
    }
    private void registerHealthCheck(WireMock wireMock, String url) {
        registerHealthCheck(wireMock, url, "OK");
    }
    private void registerHealthCheck(WireMock wireMock, String url, String body) {
        wireMock.register(
                WireMock.get(WireMock.urlEqualTo(url)).willReturn(WireMock.aResponse().withBody(body).withStatus(200)));
    }
}