Develop Reference

Mock FingerprintManager in Android tests

Is there a way to simulate or mock FingerprintManager.authenticate()? I want to write instrumented tests for my fingerprint authenticator.
I'm fine if there's a solution with a restriction that the tests can be run either on an emulator or a device. I use JUnit 4.12.

I might suggest that you don't mock it, in the spirit of not mocking things you don't own. What I might suggest instead (from the above link):
The prescription implied by "don't mock what you don't own" is to introduce your own shim/wrapper/adapter around it. This effectively cordons off the dependency to a single place in your codebase and contextualizes it in the consistent and easy-to-use style you're trying to promote within your codebase. If there's anything awkward about how one needs to invoke the dependency (maybe a chaining API, multi-step invocation, repetitive default configuration, etc.), it can be swept under the rug into that common adapter.
This feels like an instance where the humble object pattern might be appropriate.

Android TestCase subclasses

I am learning how to use the Android version of JUnit and I am confused about all the different subclasses of TestCase. In particular, how do I decide when to extend ActivityUnitTestCase, ActivityTestCase, InstrumentationTestCase or AndroidTestCase rather than ActivityInstrumentationTestCase2? Perhaps part of my confusion is that I am new to testing in general and I am unclear about the differences between the different kinds of tests (e.g. unit, functional, integration, etc.). I think some examples might help clear up some of this confusion for me.

Is it possible to create a stub of android.os.Bundle for testing under JVM?

As the title says, I want to know, if possible, how can I create a stub from Bundle to run at JVM (so not Dalvik). Since its part of android.os package, may be that is related to that impossibility.
My point is due to the fact that I want to use a mocking framework, which run at JVM, to test the Activity.onCreate() method.
I've already found this link but it seems they use a stripped custom android.jar since its rather experimental and unproven (yet I could not reproduce even with their jar, maybe I need some sleep).
If there is another alternative to mock testing this, any insights will as always be appreciated.
Thanks.

I've been successfully writing unit tests on the java jvm for classes that interact with android.jar classes. I use Powermock to mock out all android classes (like Bundle).
This link talks about using a version of the android jar that does not throw the "stub" exception on the java jvm. I have not needed to use a different version of the android jar. Using Powermock I've been able to successfully mock out anything I need to. For me this unit testing technique is not experimental.
Having said that - the unit tests for classes that extend activities, fragments, etc. become very much mock heavy. I feel it's good to move as much logic as you can into pojo classes, keeping your android extended classes as thin as possible. You can decide then if you feel it's worth isolation junit testing the android extended classes. It can certainly be done if you wish. You can also consider an integration testing framework like the one provided by Android or Robotium to test your android extended classes and their lifecycles.

jUnit testing Database operations

I'm developing an Android application with database storage.
I want to test some classes that I use to access database.
I've found ActivityInstrumentationTestCase2 to test Activities but I haven't found anything to test classes.
How can I do that? I haven't used jUnit before.
Thanks.

I always use AndroidTestCases when writing unit tests for the Android platform. They provide access to a Context instance (if required), but otherwise work like the standard JUnit test class. You may also need to look at AndroidTestRunner to test your classes. There are some good tutorials out there; now that you know what to look for, I'm sure you can find them. Happy hunting! :D

Using Android Test Framework

Android provides various packages for testing like
AndroidTestCase
ApplicationTestCase
InstrumentationTestCase
ActivityInstrumentationTestCase2 ActivityTestCase
I need to know how to decide which package is best suitable for testing my app. Some info is provided in this link
http://developer.android.com/reference/android/test/package-summary.html
But I need more clarity on this...

TestCase – Plain old JUnit test case. It can be extended to test utility classes that are not tied to the Android framework.
AndroidTestCase – It extends JUnit’s TestCase. It’s a lighter
testing class compared to
ActivityTestCase. It doesn’t need to
launch an activity to run it. Its
getContext() method allows you to get
an injected context if you need one.
Since you can get a context from this
class, you can inflate your UI objects
to test their behaviors.
ActivityInstrumentationTestCase2 – It’s the newer version of ActivityInstrumentationTestCase. ActivityInstrumentationTestCase is deprecated in Android SDK 1.5. It’s a heavier testing class compared to AndroidTestCase. It provides UI and functional testing for a single activity. You can get an injected activity that you are testing on by calling its getActivity() method. The activity being tested is launched and finished before and after each test.
ActivityUnitTestCase – It gives
the tested activity an isolated
environment. When using it to test an
activity, the activity is not attached
to the system. This gives you more
control over what kind of environment
that you want your activity to be
tested in.
ApplicationTestCase – It provides testing for Application classes. It can be used to test the life cycle of an application.
InstrumentationTestRunner – The runner that runs the Android test
cases.
I just found this..Hope this helps for others...If u want more details like when and how to use, see the APIDemos test application in the samples directory within android SDK.

Please see the class hierarchy graph drawn by myself using PowerPoint.
The accepted answer gives enough info in words. I just to make it clear using graph :)
For the InstrumentationTestCase #Zorb asked, it's parent class for ActivityTestCase among others. It enables you to call the getInstrumentation method to get an instance of instrumentation so that you can operate application, activity, and so on.

INTRO
To clarify your question and collocate the classes you are asking for, it is essential BEFORE to divide testing in two categories. JUnit tests (in theory plain Java) and Instrumentation tests (that also are part of the JUnit test package but allow you to test more SDK Android related functionalities).
Traditional JUnit tests isolate a section of code and run a test. Instrumentation tests access instead more inclusively the android components. BUT ALSO THE INSTRUMENTATION TESTS DERIVE FROM THE JUNIT PACKAGE although they are instantiated in the system even before any application code is run and this explain why are slower, furthermore they need an emulator or phone that run the app you are testing to be executed.
(Follow in Bold all the class you mention, but there are others even more used that I will write without without the bold character).
****FIRST PART**(Junit tests)**
A) Junit tests that extend TextCase (are usually faster than Instrumentation, and combine well with Mock framweworks)
AndroidTestCase: It allows to have access to the Context of the Activity you are testing and their resources, it is a base class that extends more specialized subclasses, it is ideal to access databases, filesystem data. You can easily call getContext() and access the Resources without establishing a direct contact with the Activities as will be with Instrumentation tests.
ApplicationTestCase that controls the environment where you text the application, mainly the context and the life cycle. Other really useful extensions of AndroidTestCase allow you to control Loaders,Services,and Content Providers, but for some reason still not any Broadcast receiver that you can call it [indirectly][1] with the method InstrumentationRegistry.getTargetContext() and then instantiating BroadCastReceiver. Also it is really common to use different Mock framework with Junit that is usually faster than InstrumentationTests
-.-.-.-.-.-.-.-.--
****SECOND PART**(Instrumentation tests)**
B) Instrumentation tests, that extend TestCase
Are considered functional tests, focused more to insure that they work well with the user side, the View part of MVC.They are usually slower than the other mentioned category
InstrumentationTestCase is a base class useful to send key events to UI to simulate QWERTY keyboard keys or DPAD buttons,also it launches the Activity that have to be tested, and even Intents
ActivityTestCase Usually is not used alone,it just has common code for the subclasses, but in the case you are not satisfied by the 3 classes that inherit from this one(see below) like a new future component you can use it by the time will not exist a TestCase class dedicated.
ActivityInstrumentationTestCase2 is the most used Instrumentation class to write functional tests, from the constructor is invoked the instance of the Activity to test. Basically you call the activity with getActivity() and you can pratically run any method of that Activity.
ActivityInstrumentationTestCase, is deprecated, and ActivityUnitTestCase that although is under the Instrumentation is more similar to an unit test

I found this tutorial from droidcon 09 to be really informative. Complete with downloadable working source code examples.
Edit: The link seems to be dead, as pointed out in comments.
It walks through creating a Celcius to Fahrenheit temperature converter test-first using ActivityInstrumentationTestCase2, TestCase and AndroidTestCase.