java - 单元测试中的“请求范围已关闭”球衣错误

Question

我正在编写一个使用 WireMock 模拟资源的单元测试。我正在嘲笑我的端点以引发异常，例如：

    stubFor(
            post(urlEqualTo("/myEndpoint"))
            .willReturn(aResponse().withStatus(errorCode)
                    .withHeader("Content-Type", "application/json")
                    .withBody(errorJson)));

我的客户端类的相关部分在这里测试是：

import javax.ws.rs.client.Client;
import javax.ws.rs.client.WebTarget;

public MyClient() {

    private Client client;
    private String baseUrl;

    ...

    public MyDto createObject(MyDto myDto) throws ClientErrorException {
        String resourcePath = MessageFormat.format("myEndpoint");

        return client.target(baseUrl)
                .path(resourcePath)
                .request(MediaType.APPLICATION_JSON_TYPE)
                .header(CONTENT_TYPE_HEADER, MediaType.APPLICATION_JSON)
                .post(Entity.entity(myDto, MediaType.APPLICATION_JSON), MyDto.class);
    }
}

在我的单元测试中，我尝试使用 junit 的 ExpectedException 来捕获并断言返回的错误，例如：

@Rule
public ExpectedException thrown = ExpectedException.none();

@Test
public void test_returnsError() {
    ...

    thrown.expect(NotAuthorizedException.class);
    thrown.expect(NotAuthorizedExceptionStatusMatcher.hasStatusAndError(401, UNAUTHORISED_ERROR));

    myClient.createObject(new MyDto());
}

其中 NotAuthorizedExceptionStatusMatcher 是我自己定制的匹配器类：

import javax.ws.rs.NotAuthorizedException;
import org.hamcrest.Description;
import org.hamcrest.TypeSafeMatcher;

public class NotAuthorizedExceptionStatusMatcher extends TypeSafeMatcher<NotAuthorizedException> {

    public static NotAuthorizedExceptionStatusMatcher hasStatusAndError(int status, ErrorDescription entity) {
        return new NotAuthorizedExceptionStatusMatcher(status, entity);
    }

    private final int expectedStatus;
    private final ErrorDescription expectedError;

    private int actualStatus;
    private ErrorDescription actualError;

    private NotAuthorizedExceptionStatusMatcher(int expectedStatus, ErrorDescription expectedError) {
        this.expectedStatus = expectedStatus;
        this.expectedError = expectedError;
    }

    @Override
    public boolean matchesSafely(NotAuthorizedException exception) {
        actualStatus = exception.getResponse().getStatus();
        actualError = exception.getResponse().readEntity(ErrorDescription.class);
        return expectedStatus == actualStatus && expectedError.equals(actualError);
    }

    @Override
    public void describeTo(Description description) {
        description.appendValue(actualStatus)
                .appendText(" was found instead of ")
                .appendValue(expectedStatus)
                .appendText(" and ")
                .appendValue(actualError)
                .appendText(" was found instead of ")
                .appendValue(expectedError);
    }

}

当我的匹配器尝试执行 exception.getResponse().readEntity(ErrorDescription.class) 时，我收到一个错误：

java.lang.IllegalStateException: Request scope has been already shut down.
        at jersey.repackaged.com.google.common.base.Preconditions.checkState(Preconditions.java:149)
        at org.glassfish.jersey.process.internal.RequestScope.retrieveCurrent(RequestScope.java:239)
        at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:416)
        at org.glassfish.jersey.client.InboundJaxrsResponse.readEntity(InboundJaxrsResponse.java:108)
        at MyProject.NotAuthorizedExceptionStatusMatcher.matchesSafely(NotAuthorizedExceptionStatusMatcher.java:28)
        at MyProject.NotAuthorizedExceptionStatusMatcher.matchesSafely(NotAuthorizedExceptionStatusMatcher.java:8)
        at org.hamcrest.TypeSafeMatcher.matches(TypeSafeMatcher.java:65)
        at org.hamcrest.core.AllOf.matches(AllOf.java:27)
        at org.hamcrest.DiagnosingMatcher.matches(DiagnosingMatcher.java:12)
        at org.junit.internal.matchers.StacktracePrintingMatcher.matchesSafely(StacktracePrintingMatcher.java:29)
        at org.junit.internal.matchers.StacktracePrintingMatcher.matchesSafely(StacktracePrintingMatcher.java:14)
        at org.hamcrest.TypeSafeMatcher.matches(TypeSafeMatcher.java:65)
        at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:12)
        at org.junit.Assert.assertThat(Assert.java:956)
        at org.junit.Assert.assertThat(Assert.java:923)
        at org.junit.rules.ExpectedException.handleException(ExpectedException.java:252)
        at org.junit.rules.ExpectedException.access$000(ExpectedException.java:106)
        at org.junit.rules.ExpectedException$ExpectedExceptionStatement.evaluate(ExpectedException.java:241)
        at com.github.tomakehurst.wiremock.junit.WireMockRule$1.evaluate(WireMockRule.java:67)
        at org.junit.rules.RunRules.evaluate(RunRules.java:20)
        at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
        at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
        at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
        at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
        at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
        at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
        at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
        at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
        at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
        at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:242)
        at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:137)
        at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:112)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:189)
        at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:165)
        at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:85)
        at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:115)
        at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:75)

如果我使用 try-catch 块来断言异常，同样的代码似乎可以工作，但我更喜欢 ExpectedException 方法。有什么想法可能是这里的原因吗？我怀疑这是我正在使用的框架的组合，但我不太确定从这里去哪里。

Answer 1

这有可能是由测试类中规则的顺序引起的。这听起来很奇怪，但是如果规则的顺序被解释为[WireMock, ExpectedException]那么 junit 框架实际上是按照这个顺序构建它们的。这些规则被设计为测试周围的装饰器，这样每个规则都可以在任何 @Before 块之前和任何 @After 之后采取行动。

所以在上面列出的例子中，规则被解析[WireMock, ExpectedException]那么执行顺序将是：

1. WireMock 启动服务器

2. ExpectedException 初始化（如果有）

3. @执行前

4. 执行测试

5. @执行后

6. ExpectedException 评估和操作

7. WireMock 关闭服务器

我认为这个案例实际上是您正在寻找的案例。

如果我们切换 WireMock 和 ExpectedException 的顺序：

1. ExpectedException 初始化（如果有）

2. WireMock 启动服务器

3. @执行前

4. 执行测试

5. @执行后

6. WireMock 关闭服务器

7. ExpectedException 评估和操作

然后，当 ExpectedException 规则被允许评估异常中的响应时，所有服务和状态都已被 Wiremock 销毁。

---

使用RuleChain将保证您的规则顺序，并解决问题（在我能够模拟的范围内）。

交换passOrder和failOrder链以查看测试失败！

public class WiremockTest {

    public WireMockRule wireMockRule = new WireMockRule(8089);
    public ExpectedException thrown = ExpectedException.none();    
    @Rule
    public RuleChain passOrder = RuleChain.outerRule(wireMockRule).around(thrown);
    //public RuleChain failOrder = RuleChain.outerRule(thrown).around(wireMockRule);

    @Test
    public void exampleTestExpectConnectionException() throws Exception {
        thrown.expect(ConnectionObjectContainer.class);

        //Custom matcher that gets something from the cached connection after the failure occurs.
        thrown.expect(new BaseMatcher<ConnectionObjectContainer> (){

            public boolean matches(Object item) {
                ConnectionObjectContainer container = (ConnectionObjectContainer) item;
                try {
                    //XXX This line is intended to mimic the NotAuthorizedException class behavior
                    System.out.println(container.getResponseCode());

                } catch (IOException exception) {
                   throw new RuntimeException(exception);
                }
                return true;
            }

            public void describeTo(Description description) {
                //Not used in sample
            }});


        stubFor(get(urlPathMatching("/my/resource/[0-9]+")).willReturn(aResponse().withStatus(200).withHeader(
            "Content-Type", "text/xml").withBody("<response>Some content</response>")));

        URL obj = new URL("http://localhost:8089/my/resource/121");
        HttpURLConnection con = (HttpURLConnection) obj.openConnection();

        // optional default is GET
        con.setRequestMethod("GET");

        throw new ConnectionObjectContainer(con);
    }



    /**
     * My Exception class that caches the HttpURLConnection and provides an accessor for the response code to the Matcher of my 
     * ExpectedException configuration.
     * 
     * @since Jun 17, 2016
     *
     */
    public class ConnectionObjectContainer extends Exception {
        HttpURLConnection connection;
        public ConnectionObjectContainer(HttpURLConnection conn) {
            this.connection = conn;
        }

       public int getResponseCode() throws IOException {
            return connection.getResponseCode();
        }
    }


}