is there a more elegant way to do an assert throws exception in Android then this?
public void testGetNonExistingKey() {
try {
alarm.getValue("NotExistingValue");
fail( );
} catch (ElementNotFoundException e) {
}
}
Something like this does not work?!
#Test(expected=ElementNotFoundException .class)
Thanks, Mark
Are you using a junit4 test runner? The #Test annotation won't work if you're running a junit3 test runner. Check the version that you're using.
Secondly, the recommended way to check for exceptions in your code is to use a Rule (introduced in junit 4.7).
#Rule
public ExpectedException exception = ExpectedException.none();
#Test
public void throwsIllegalArgumentExceptionIfIconIsNull() {
// do something
exception.expect(IllegalArgumentException.class);
exception.expectMessage("Icon is null, not a file, or doesn't exist.");
new DigitalAssetManager(null, null);
}
You can continue to use the #Test(expected=IOException.class), but the above has the advantage that if an exception is thrown before the exception.expect is called, then the test will fail.
I did something very similar to hopia's answer with a couple of improvements. I made it return the exception object so that you can check its message or any other properties, and I declared a Testable interface to replace Runnable because Runnable doesn't let your code under test throw checked exceptions.
public interface Testable {
public void run() throws Exception;
}
public <T extends Exception> T assertThrows(
final Class<T> expected,
final Testable codeUnderTest) throws Exception {
T result = null;
try {
codeUnderTest.run();
fail("Expecting exception but none was thrown.");
} catch(final Exception actual) {
if (expected.isInstance(actual)) {
result = expected.cast(actual);
}
else {
throw actual;
}
}
return result;
}
Here's an example of calling it.
InvalidWordException ex = assertThrows(
InvalidWordException.class,
new Testable() {
#Override
public void run() throws Exception {
model.makeWord("FORG", player2);
}
});
assertEquals(
"message",
"FORG is not in the dictionary.",
ex.getMessage());
If you're using Kotlin, you can take advantage of reified types to avoid passing the Exception subclass as an argument:
inline fun <reified T : Exception> assertThrows(runnable: () -> Any?) {
try {
runnable.invoke()
} catch (e: Throwable) {
if (e is T) {
return
}
Assert.fail("expected ${T::class.qualifiedName} but caught " +
"${e::class.qualifiedName} instead")
}
Assert.fail("expected ${T::class.qualifiedName}")
}
#Test
fun exampleTest() {
val a = arrayOf(1, 2, 3)
assertThrows<IndexOutOfBoundsException> {
a[5]
}
}
This is how I do it. I create a static method called assertThrowsException that takes in as arguments an expected exception class and a Runnable which contains the code under test.
import junit.framework.Assert;
public SpecialAsserts {
public void assertThrowsException(final Class<? extends Exception> expected, final Runnable codeUnderTest) {
try {
codeUnderTest.run();
Assert.fail("Expecting exception but none was thrown.");
} catch(final Throwable result) {
if (!expected.isInstance(result)) {
Assert.fail("Exception was thrown was unexpected.");
}
}
}
}
This is the sample code to use the special assert in your test class (that extends AndroidTestCase or one of its derivatives):
public void testShouldThrowInvalidParameterException() {
SpecialAsserts.assertThrowsException(InvalidParameterException.class, new Runnable() {
public void run() {
callFuncThatShouldThrow();
}
});
}
Yes, there's a lot of work, but it's better than porting junit4 to android.
With junit3 the following might help.
public static void assertThrows(Class<? extends Throwable> expected,
Runnable runnable) {
try {
runnable.run();
} catch (Throwable t) {
if (!expected.isInstance(t)) {
Assert.fail("Unexpected Throwable thrown.");
}
return;
}
Assert.fail("Expecting thrown Throwable but none thrown.");
}
public static void assertNoThrow(Runnable runnable) {
try {
runnable.run();
} catch (Throwable t) {
Assert.fail("Throwable was unexpectedly thrown.");
}
}
Related
I have following code
private void tryToLauch() {
try {
launch();
} catch (MyException e) {
postError(e.getErrorMessage());
e.printStackTrace();
}
}
How can I convert it to Rx that will retry in some period in case of exception ?
Given that your method have as return type void, I suggest you to use a Completable.
You can try this solution, using RxJava 2
Completable myCompletable = Completable.fromAction(new Action() {
#Override
public void run() throws Exception {
launch();
}
}).retry(3 /*number of times to retry*/, new Predicate<Throwable>() {
#Override
public boolean test(Throwable throwable) throws Exception {
return throwable instanceof MyException;
}
});
Then subscribe to the Completable
myCompletable.subscribeOn(SubscribeScheduler)
.observeOn(ObserveScheduler)
.subscribe(this::onComplete, this::onError);
Hope this helps.
I'm trying to figure out how to handle errors with Room. I have the following interactor that inserts a task in the database:
TaskInteractor.java
public class TaskInteractor extends AbstractInteractor implements TaskContract.Interactor {
final TaskRepository mRepository;
interface Callback {
void onSuccess();
void onFailure(Throwable t);
}
#Inject
public TaskInteractor(WorkerThread workerThread,
MainThread mainThread,
TaskRepository repository) {
super(workerThread, mainThread);
this.mRepository = repository;
}
#Override
public void insertTask(final Task task, final Callback callback)
throws SQLiteException {
mWorkerThread.get().execute(new Runnable() {
#Override
public void run() {
try {
mRepository.insertTask(task);
} catch (SQLiteException exeption) {
Timber.e("Insertion failed. Exception: " + exeption.getMessage());
callback.onFailure(exeption);
throw exeption;
}
Timber.d("Insertion succeeded.");
callback.onSuccess();
}
});
}
}
In insertTask I use a try-catch block to check if a SQLiteException happened. If it does, I throw the exception.
But is this a good way of handling errors or is there maybe a better way?
The code below won't crash when running in JUnit environment. But it crashes when running in the app. I can see error logs in the console, but tests are marked as passed.
#Test
public void test() {
Observable observable = Observable.error(new RuntimeException());
observable.subscribe();
}
So, the question is: how to make it crash in JUnit. Because yeah, if something doesn't work in the app it's a good thing if it doesn't work in the unit tests also :)
And in this example I have direct access to the observable. But in my real tests I don't have that. Real observables are just internal details of classes that being tested. The most thing I can to do is to inject schedulers or something.
So, how to make it crash without having direct access to the observable?
Also, I've just checked this code doesn't crash either:
#Test
public void test() {
Observable observable = Observable.error(new RuntimeException());
observable.subscribe(new Consumer() {
#Override
public void accept(Object o) throws Exception {
throw new RuntimeException();
}
}, new Consumer<Throwable>() {
#Override
public void accept(Throwable throwable) throws Exception {
throw new RuntimeException();
}
});
}
According to akarnokd this is RxJava2 specific problem.
"Such usages no longer throw synchronously in 2.x but end up in the plugin handler for errors."
It is possible to check if any errors was thrown with this code
public static List<Throwable> trackPluginErrors() {
final List<Throwable> list = Collections.synchronizedList(new ArrayList<Throwable>());
RxJavaPlugins.setErrorHandler(new Consumer<Throwable>() {
#Override
public void accept(Throwable t) {
list.add(t);
}
});
return list;
}
A small trick I use to tackle this problem, is creating a JUnit4 TestRule class that setups a custom RxJava error handler so it can throw when an unhandled RxJava error occurs:
/**
* A rule that detects RxJava silent errors and reports them to JUnit
(by throwing them).
*/
public class RxErrorRule implements TestRule {
#Override
public Statement apply(Statement base, Description description) {
return new Statement() {
#Override
public void evaluate() throws Throwable {
Consumer<? super Throwable> previous = RxJavaPlugins.getErrorHandler();
AtomicReference<Throwable> result = setupErrorHandler();
try {
base.evaluate();
} finally {
RxJavaPlugins.setErrorHandler(previous);
}
if (result.get() != null) {
throw result.get();
}
}
};
}
private AtomicReference<Throwable> setupErrorHandler() {
AtomicReference<Throwable> result = new AtomicReference<>();
RxJavaPlugins.setErrorHandler(new Consumer<Throwable>() {
#Override
public void accept(Throwable throwable) {
result.set(throwable);
}
});
return result;
}
}
And in the unit test:
public class YourRxTest {
#Rule
public RxErrorRule errorRule = new RxErrorRule();
// ...
}
Use TestSubscriber
Observable observable = Observable.error(new RuntimeException());
TestSubscriber testSubscriber = TestSubscriber.create();
observable.subscribe(testSubscriber);
testSubscriber.assertTerminalEvent();
testSubscriber.assertError(RuntimeException.class);
Which is the best way to take a screenshot when one scenario fails using Robotium and Cucumber?
I have tried (without success, because it doesn't execute runTest method) with this:
import cucumber.api.CucumberOptions;
import cucumber.api.java.After;
import cucumber.api.java.Before;
#CucumberOptions(features = "features", tags = {"~#ignore"})
public class CustomInstrumentationTestCase extends ActivityInstrumentationTestCase2<LaunchActivity> {
protected Solo solo;
public CustomInstrumentationTestCase() {
super(LaunchActivity.class);
}
#Before
public void before() throws Exception {
//...
}
#After
public void after() throws Exception {
//...
}
#Override
protected void runTest() throws Throwable {
try {
super.runTest();
} catch (Throwable t) {
final String testCaseName = String.format("%s.%s", getClass().getName(), getName());
solo.takeScreenshot(testCaseName);
Log.w("Boom! Screenshot!", String.format("Captured screenshot for failed test: %s", testCaseName));
throw t;
}
}
}
And I have set the permissions in the manifest:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
Your testclass seems fine. The runTest() methode is used to catch errors and failures and as a result make a screenshot.
To your class simply add a test like this:
public void testFailsForScreenShot(){
fail();
}
Than run the test and you will find a screenshot.
Greetings
EDIT: Test for Screenshot:
import android.util.Log;
import com.robotium.solo.Solo;
public class TestScreenshot extends ActivityInstrumentationTestCase2<LauncherActivity> {
private Solo solo;
public TestScreenshot(){
super(LauncherActivity.class);
}
#Override
protected void setUp() throws Exception {
super.setUp();
solo = new Solo(getInstrumentation(), getActivity());
}
//Test if "Test" fails and takes Screenshot
public void testFailForScreenshot(){
fail();
}
#Override
public void runTest() throws Throwable {
try {
super.runTest();
} catch (Throwable t) {
String testCaseName = String.format("%s.%s", getClass().getName(), getName());
solo.takeScreenshot(testCaseName);
Log.w("Screenshot taken.", String.format("Captured screenshot for failed test: %s", testCaseName));
throw t;
}
}
In my Android application I have set up Volley.
Robolectric.application is initialized and all other tests runs smoothly.
I get this error when trying to get mocked HTTP response.
This is my test:
#RunWith(MyRobolectricTestRunner.class)
public class ApiTests {
#Inject
protected Api api;
#Before
public void setUp() {
ObjectGraph.create(new AndroidModule(Robolectric.application), new TestApplicationModule()).inject(this);
}
#Test
public void shouldGetErrorList() throws Exception {
Project project = new Project("test", "test", "test", DateTime.now());
addPendingProjectsErrorsResponse("response.json"); //adding response to FakeHttpLayer
api.getProjectErrors(project, new Listener<ProjectErrors>() {
#Override
public void onResponse(ProjectErrors response) {
assertNotNull(response);
}
}, new ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
throw new RuntimeException(error);
}
}
);
}
}
This is error I get:
Exception in thread "Thread-3" java.lang.NullPointerException
at org.robolectric.shadows.ShadowLooper.getMainLooper(ShadowLooper.java:59)
at android.os.Looper.getMainLooper(Looper.java)
at org.robolectric.Robolectric.getUiThreadScheduler(Robolectric.java:1301)
at org.robolectric.shadows.ShadowSystemClock.now(ShadowSystemClock.java:15)
at org.robolectric.shadows.ShadowSystemClock.uptimeMillis(ShadowSystemClock.java:25)
at org.robolectric.shadows.ShadowSystemClock.elapsedRealtime(ShadowSystemClock.java:30)
at android.os.SystemClock.elapsedRealtime(SystemClock.java)
at com.android.volley.VolleyLog$MarkerLog.add(VolleyLog.java:114)
at com.android.volley.Request.addMarker(Request.java:174)
at com.android.volley.CacheDispatcher.run(CacheDispatcher.java:92)
I had same error and avoid it by using my own (and ugly) SystemClock shadow.
shadow class:
#Implements(value = SystemClock.class, callThroughByDefault = true)
public static class MyShadowSystemClock {
public static long elapsedRealtime() {
return 0;
}
}
test code:
#Test
#Config(shadows = { MyShadowSystemClock.class, ... })
public void myTest() {
}
Another workaround would be to disable Volley logging by calling
VolleyLog.DEBUG = false;
in your setUp method.