在Android导航组件中测试导航动作答案

【问题标题】：Testing navigation action in navigation component in Android在Android导航组件中测试导航动作
【发布时间】：2020-04-12 09:36:42
【问题描述】：

最近我将导航组件集成到一个基于单一活动模型的项目中。我尝试根据 android 文档中的教程添加 ui 测试。但是，当我对该教程进行一些修改时，它不起作用。我的片段中有以下代码。

val bundle = Bundle().apply {
   putString(UserTrackingConstants.VIEW, UserTrackingConstants.HOME)
}

btnSignUp.setOnClickListener {
findNavController().navigate(R.id.action_from_home_fragment_to_registration_fragment,bundle)
}

因此，每当单击 btnSignUp 时，它都会调用以下导航操作。它工作完美。然后我添加了以下测试。

@Test
    fun testRegisterButtonClicked() {
        val mockNavController = mock(NavController::class.java)
        val bundle = bundleOf(
                UserTrackingConstants.VIEW to UserTrackingConstants.HOME
        )
        val scenario = launchFragmentInContainer<HomeFragment>()
        scenario.onFragment { fragment ->
            Navigation.setViewNavController(fragment.requireView(), mockNavController)
        }
        onView(withId(R.id.btnSignUp))
                .perform(click())
        verify(mockNavController).navigate(R.id.action_from_home_fragment_to_registration_fragment, bundle)
    }

它抛出了以下异常

E/TestRunner: ----- begin exception -----
    Argument(s) are different! Wanted:
    navController.navigate(
        2131296310,
        Bundle[{view=home}]
    );
    -> at HomeFragmentTest.testRegisterButtonClicked(HomeFragmentTest.kt:87)
    Actual invocation has different arguments:
    navController.navigate(
        2131296310,
        Bundle[{view=home}]
    );
    -> at HomeFragment$setupObservers$2.onClick(HomeFragment.kt:84)

        at HomeFragmentTest.testRegisterButtonClicked(HomeFragmentTest.kt:87)
        at java.lang.reflect.Method.invoke(Native Method)
        at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
        at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
        at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
        at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
        at androidx.test.internal.runner.junit4.statement.RunBefores.evaluate(RunBefores.java:80)
        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 androidx.test.ext.junit.runners.AndroidJUnit4.run(AndroidJUnit4.java:104)
        at org.junit.runners.Suite.runChild(Suite.java:128)
        at org.junit.runners.Suite.runChild(Suite.java:27)
        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$2.evaluate(ParentRunner.java:268)
        at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
        at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
        at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
        at androidx.test.internal.runner.TestExecutor.execute(TestExecutor.java:56)
        at androidx.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:392)
        at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:2189)
    ----- end exception -----

Argument(s) are different! Wanted:
navController.navigate(
2131296310,
Bundle[{view=home}]
);
-> at HomeFragmentTest.testRegisterButtonClicked(HomeFragmentTest.kt:87)
Actual invocation has different arguments:
navController.navigate(
2131296310,
Bundle[{view=home}]
);
-> at HomeFragment$setupObservers$2.onClick(HomeFragment.kt:84)

at HomeFragmentTest.testRegisterButtonClicked(HomeFragmentTest.kt:87)
at java.lang.reflect.Method.invoke(Native Method)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at androidx.test.internal.runner.junit4.statement.RunBefores.evaluate(RunBefores.java:80)
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 androidx.test.ext.junit.runners.AndroidJUnit4.run(AndroidJUnit4.java:104)
at org.junit.runners.Suite.runChild(Suite.java:128)
at org.junit.runners.Suite.runChild(Suite.java:27)
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$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
at androidx.test.internal.runner.TestExecutor.execute(TestExecutor.java:56)
at androidx.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:392)
at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:2189)

我没有从 logcat 中得到任何有用的信息。似乎论点是相同的，它应该通过。如果我不通过捆绑，它工作正常。我关注了以下链接https://developer.android.com/guide/navigation/navigation-testing 中的文档。我的问题是是否有人遇到过此类异常以及如何使用 bundle 测试导航组件？

【问题讨论】：

标签： android ui-testing android-architecture-navigation android-mvvm

【解决方案1】：

您遇到如此奇怪的测试结果的原因是 Bundle 类没有覆盖 equals() 和 toString() 方法，因此 Bundle 实例通过引用进行比较（并且引用显然与您的预期不同bundle 和实际的）——由于 Mockito 依赖这些方法来验证对象是否相同，因此您的测试用例将失败。

要解决此问题，您可以为Mockito.verify() 使用自定义匹配器：

public class BundleEquals implements ArgumentMatcher, ContainsExtraTypeInfo, Serializable {

    @Nullable
    private final Bundle expected;

    public BundleEquals(@Nullable Bundle expected) {
        this.expected = expected;
    }

    @Override
    public boolean matches(Bundle actual) {
        if (expected == null && actual == null) {
            return true;
        }

        if (expected == null || actual == null) {
            return false;
        }

        return areBundlesEqual(expected, actual);
    }

    private boolean areBundlesEqual(@NonNull Bundle expected, @NonNull Bundle actual) {
        if (expected.size() != actual.size()) {
            return false;
        }

        if (!expected.keySet().containsAll(actual.keySet())) {
            return false;
        }

        for (String key : expected.keySet()) {
            @Nullable Object expectedValue = expected.get(key);
            @Nullable Object actualValue = actual.get(key);

            if (expectedValue instanceof Bundle && actualValue instanceof Bundle) {
                if (!areBundlesEqual((Bundle) expectedValue, (Bundle) actualValue)) {
                    return false;
                }
            } else if (!Objects.equals(expectedValue, actualValue)) {
                return false;
            }
        }

        return true;
    }

    public String toStringWithType() {
        String clazz = expected != null ? expected.getClass().getSimpleName() : null;
        return "(" + clazz + ") " + describe(expected);
    }

    private String describe(Object object) {
        return ValuePrinter.print(object);
    }

    @Override
    public boolean typeMatches(Object actual) {
        return expected != null && actual != null && actual.getClass() == expected.getClass();
    }

    public String toString() {
        return describe(expected);
    }

}

注意： ContainsExtraTypeInfo 和 Serializable 实现在这里不是必需的，但是当由于包不匹配而导致测试失败时，它们会为您提供详细的预期和实际参数描述，

要应用匹配器，您应该使用如下内容：

verify(mockNavController).navigate(eq(R.id.action_from_home_fragment_to_registration_fragment), argThat(new BundleEquals(bundle));

注意这里需要eq()，以便 Mockito 不会混淆不同的匹配器：让您的操作 id 未包装会导致验证失败。

【讨论】：