CODEWITHSUNDEEP
androidjunitnullpointerexceptionloaderandroid-testing
Terry
Terry

Reputation: 14897

Testing for Exception with LoaderTestCase

In my Android JUnit test case, a LoaderTestCase, I want to test if my Loader throws an exception or returns null. I am seeing that a NullPointerException is thrown in the test, and the test is aborted.

I am trying to catch the exception like this:

try {
    getLoaderResultSynchronously(new HistoricDataLoader(getContext(), url, username, password,
        https, md5, station, stationMetaData, from, to));
    // Expected exception wasn't thrown: fail.
    fail();
} catch (NullPointerException e) {
    // Expected exception was thrown. Success.
    Log.e(TAG, e.getMessage());
}

But instead of catching the exception, the LoaderTestCase is aborting with the following exception:

java.lang.NullPointerException
        at java.util.concurrent.ArrayBlockingQueue.checkNotNull(ArrayBlockingQueue.java:126)
        at java.util.concurrent.ArrayBlockingQueue.offer(ArrayBlockingQueue.java:295)
        at java.util.AbstractQueue.add(AbstractQueue.java:66)
        at java.util.concurrent.ArrayBlockingQueue.add(ArrayBlockingQueue.java:282)
        at android.test.LoaderTestCase$2.onLoadComplete(LoaderTestCase.java:70)
        at android.content.Loader.deliverResult(Loader.java:144)
        at android.content.AsyncTaskLoader.dispatchOnLoadComplete(AsyncTaskLoader.java:265)
        at android.content.AsyncTaskLoader$LoadTask.onPostExecute(AsyncTaskLoader.java:92)
        at android.os.AsyncTask.finish(AsyncTask.java:632)
        at android.os.AsyncTask.access$600(AsyncTask.java:177)
        at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:645)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:136)
        at android.app.ActivityThread.main(ActivityThread.java:5086)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:515)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
        at dalvik.system.NativeStart.main(Native Method)

Can you tell me how I can

Edit:

I am aware of how to test for exceptions in JUnit 4. Right now I am doing my Android tests with JUnit 3, hence I catch them like shown in the code. If your answer is that I should use JUnit 4 instead of JUnit 3, please explain why that should make a difference. The Exception is thrown and aborts the test inside the method getLoaderResultSynchronously(). It is not passed up the calling chain, so I don't see how JUnit 4 should be able to catch it.

Upvotes: 1

Views: 174

Answers (1)

jasper
jasper

Reputation: 355

In jUnit 4 you can expect Exceptions using annotations, your code could look something like this:

    @Test(expected=NullPointerException.class)
    public void loaderNpe() {
        getLoaderResultSynchronously(new HistoricDataLoader(getContext(), url,    username, password,vhttps, md5, station, stationMetaData, from, to));
    }

Upvotes: 0

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