java - Why is my JSONObject related unit test failing?

Question

I'm running my tests using gradle testFlavorType

JSONObject jsonObject1 = new JSONObject();
JSONObject jsonObject2 = new JSONObject();
jsonObject1.put("test", "test");
jsonObject2.put("test", "test");
assertEquals(jsonObject1.get("test"), jsonObject2.get("test"));

The above test succeeds.

jsonObject = new SlackMessageRequest(channel, message).buildBody();
String channelAssertion = jsonObject.getString(SlackMessageRequest.JSON_KEY_CHANNEL);
String messageAssertion = jsonObject.getString(SlackMessageRequest.JSON_KEY_TEXT);
assertEquals(channel, channelAssertion);
assertEquals(message, messageAssertion);

But the above two requests fail. The stack trace says that channelAssertion and messageAssertion are null, but not sure why. My question is: Why are the above two asserts failing?

Below is the SlackMessageRequest.

public class SlackMessageRequest
        extends BaseRequest {
    // region Variables

    public static final String JSON_KEY_TEXT = "text";
    public static final String JSON_KEY_CHANNEL = "channel";

    private String mChannel;
    private String mMessage;

    // endregion

    // region Constructors

    public SlackMessageRequest(String channel, String message) {
        mChannel = channel;
        mMessage = message;
    }

    // endregion

    // region Methods

    @Override
    public MethodType getMethodType() {
        return MethodType.POST;
    }    

    @Override
    public JSONObject buildBody() throws JSONException {
        JSONObject body = new JSONObject();
        body.put(JSON_KEY_TEXT, getMessage());
        body.put(JSON_KEY_CHANNEL, getChannel());
        return body;
    }

    @Override
    public String getUrl() {
        return "http://localhost:1337";
    }

    public String getMessage() {
        return mMessage;
    }

    public String getChannel() {
        return mChannel;
    }

// endregion
}

Below is the stacktrace:

junit.framework.ComparisonFailure: expected:<@tk> but was:<null>
    at junit.framework.Assert.assertEquals(Assert.java:100)
    at junit.framework.Assert.assertEquals(Assert.java:107)
    at junit.framework.TestCase.assertEquals(TestCase.java:269)
    at com.example.app.http.request.SlackMessageRequestTest.testBuildBody(SlackMessageRequestTest.java:30)
    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:483)
    at junit.framework.TestCase.runTest(TestCase.java:176)
    at junit.framework.TestCase.runBare(TestCase.java:141)
    at junit.framework.TestResult$1.protect(TestResult.java:122)
    at junit.framework.TestResult.runProtected(TestResult.java:142)
    at junit.framework.TestResult.run(TestResult.java:125)
    at junit.framework.TestCase.run(TestCase.java:129)
    at junit.framework.TestSuite.runTest(TestSuite.java:252)
    at junit.framework.TestSuite.run(TestSuite.java:247)
    at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:86)
    at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecuter.runTestClass(JUnitTestClassExecuter.java:86)
    at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecuter.execute(JUnitTestClassExecuter.java:49)
    at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassProcessor.processTestClass(JUnitTestClassProcessor.java:64)
    at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.processTestClass(SuiteTestClassProcessor.java:50)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:35)
    at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
    at org.gradle.messaging.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:32)
    at org.gradle.messaging.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:93)
    at com.sun.proxy.$Proxy2.processTestClass(Unknown Source)
    at org.gradle.api.internal.tasks.testing.worker.TestWorker.processTestClass(TestWorker.java:106)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:35)
    at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
    at org.gradle.messaging.remote.internal.hub.MessageHub$Handler.run(MessageHub.java:360)
    at org.gradle.internal.concurrent.DefaultExecutorFactory$StoppableExecutorImpl$1.run(DefaultExecutorFactory.java:64)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

EDIT 5:55PM EST

I've figured out that I can log with System.out.println("") and then see the results by running gradle testFlavorType --debug and by trial and error I've discovered the following weird situation:

@Override
public JSONObject buildBody() throws JSONException {
    System.out.println("buildBody mChannel = " + mChannel);
    System.out.println("buildBody mMessage = " + mMessage);
    JSONObject body = new JSONObject();
    body.put(JSON_KEY_TEXT, getMessage());
    body.put(JSON_KEY_CHANNEL, getChannel());

    if (body.length() != 0) {
        Iterator<String> keys = body.keys();

        if (keys.hasNext()) {
            do {
                String key = keys.next();
                System.out.println("keys: " + key);
            } while (keys.hasNext());
        }
    } else {
        System.out.println("There are no keys????");
    }

    return body;
}

For some reason, "There are no keys????" is printing out?!?!?!?! Why?!

EDIT 6:20PM EST

I've figured out how to debug unit tests. According to the debugger, the assigned JSONObject is returning "null". I have no clue what this means (see below). Since I think this is relevant, my gradle file includes the following:

testOptions {
    unitTests.returnDefaultValues = true
}

It's especially strange because if I construct a JSONObject inside the test, then everything works fine. But if it is part of the original application's code, then it doesn't work and does the above.

Answer 1

As Lucas says, JSON is bundled up with the Android SDK, so you are working with a stub.

The current solution is to pull JSON from Maven Central like this:

dependencies {
    ...
    testImplementation 'org.json:json:20210307'
}

You can replace the version 20210307 with the the latest one depending on the Android API. It is not known which version of the maven artefact corresponds exactly/most closely to what ships with Android.

Alternatively, you can download and include the jar:

dependencies {
    ...
    testImplementation files('libs/json.jar')
}

Note that you also need to use Android Studio 1.1 or higher and at least build tools version 22.0.0 or above for this to work.

Related issue: #179461