Develop Reference

Is it possible to use dagger at android project unit testing?

I want to use Dagger + Robolectric in src/test/java package. Is it possible? How?
Somebody wrote their Robolectric tests at src/androidTest/java package then used Dagger, But Robolectric is a framework that runs your tests inside the JVM on your workstation in seconds.
If I write my test in src/androidTest/java package it won't run inside the JVM.
Anyway, Is it right to use Dagger at src/test/java package? Is it possible?

Yes, it's perfectly possible to use dagger in robolectric tests. But in general
You don’t have to use Dagger for single-class unit tests
https://google.github.io/dagger/testing.html

How to do Unit testing in Android Studio?

I am a Beginner in Android. I want to write a unit testing code in Android studio. How to run that testing in real device and also how to get the test result. I can able to see AndroidTest folder in src folder.

It is a good practice to write Unit Test code from scratch. But if you have learned a little bit of Unit testing basic you can take advantage of IntelliJ plugins for Android Studio to generate Unit Testing code very easily.
Try this:
TestMe(https://plugins.jetbrains.com/plugin/9471-testme)
Auto Generate Unit Tests for source class in Java or Groovy.
No more boilerplate!
Features:
Auto-generate Java or Groovy test code with JUnit 4/5, TestNG or Spock frameworks
Auto-generate Mockito mocks
Generate test params and assertion statements
Quick-Start:
http://weirddev.com/testme/

How to run a Junit5 test with Android dependencies and robolectric

I am trying to run a unit test like that:
#org.junit.jupiter.api.Test
void junit5codeCoverage() {
final int result = new Foo().junit5();
Assert.assertEquals(Looper.getMainLooper().getThread(), Thread.currentThread());
assertEquals(-1, result);
}
That is a Junit5 test with Android dependencies (i.e Looper.getMainLooper()) with Robolectric.
I am using the junit5 android plugin from mannodermaus that allows running junit5 within Android setups. But this does not work out of the box because it would not load robolectric. So I tried alixwar's branch that would tackle robolectric and junit5 test coverage, but still, would not use Android classes.
I furthermore started to investigate how to run a robolectric test on junit5, which would require understanding how the RobolectricTestRunner works and how to port the code to the JUnit5 platform. I have little understanding of the new junit5 platform, but I figured out that I could build on top of the org.junit.platform.runner.JUnitPlatform runner, to follow the test runner concept, which is part of the junit-platform-runner package. But this is so far away from the original Junit4 SandBoxTestRunner that I couldn't manage to complete the port.
So what would be the most feasible path to implement robolectric junit5 support, or is there any (obvious) concept I am missing?

I am trying to do this too, but it seems that at the time of this writing, Robolectric simply does not support junit5.
See the discussion here: https://github.com/robolectric/robolectric/issues/2996
Some workarounds are described in that discussion, but for now I am just going to stick to junit4.

You can use junit-vintage-engine to run test with runners from JUnit4.
Just add org.junit.vintage:junit-vintage-engine to your dependencies, thus you can org.junit.runner.RunWith annotation to your tests.

Autogenerate unit test stubs on Android studio

I am creating the unit test for some legacy android codes.
Currently i need to manually create the unit test for each class/method in test/java.
Is there an automated way to auto generate all the test stubs? ideally from the Android studio IDE? (similar to how parasoft can autogenerate empty test stubs for C++ classes and methods).
I am using robolectric on Android studio 1.2.1

Like this: Right-click the class name. Go To -> Test. Select the function, Done.

Android JUnit4 testing

I want to run some JUnit4 tests. The code relies on some Android libraries(Android XML parser), but does not create any activites and so on. When I try to run tests I got that an Android class that I need was not found. Is there any way to run JUnit4 tests with Android code, not to test activity but to test code with some libraries.

I had the same problem and tried to adapt JUnit4 to Android's existing TestRunner - without success. Therefore I created a new project called JUnit4Android. It's a TestRunner application library for JUnit4 and JUnit3 tests and test suites. So you can run your existing JUnit4 tests with it. Please find more information on GitHub:
https://github.com/dthommes/JUnit4Android/wiki

There is no way (that I'm aware of) to use JUnit4 on Android. It does support JUnit3 though, if that's an option for you?
Alternatively, you could use Robolectric and run your tests on your development machine (where you'll be able to use whichever unit test framework you like). Whether this will work for you depends on exactly what you're testing, but it might be worth a go?

It might be little bit late, but there's finally an official update from Google about junit4:
based on Android-test-kit project and some other sources it's clear that:
The AndroidJUnitRunner is a new unbundled test runner for Android, which is part of the
Android Support Test Library and can be downloaded via the Android
Support Repository. The new runner contains all improvements of
GoogleInstrumentationTestRunner and adds more features:
- JUnit4 support
- Instrumentation Registry for accessing Instrumentation, Context and Bundle Arguments
- Test Filters #SdkSupress and #RequiresDevice
- Test timeouts
- Sharding of tests
- RunListener support to hook into the test run lifecycle
- Activity monitoring mechanism ActivityLifecycleMonitorRegistry
Actually, it's already presented in Support Repository. If You go to
%ANDROID_HOME%\extras\android\m2repository\com\android\support\test\testing-support-lib\
it's possible to find testing-support-lib in there (aar, jars etc.) which allows to use JUnit4. Even more, it contains espresso library same location which is handy for UI testing. Seems Android sites and support lib official references will be updated soon with that info.