Referring to https://developer.android.com/training/testing/unit-testing/local-unit-tests.html and https://medium.com/@ali.muzaffar/the-basics-of-unit-and-instrumentation-testing-on-android-7f3790e77bd, I added
testCompile 'junit:junit:4.12'
in my gradle. Then I created a new test class, but apparently
@Test
throws 'Cannot resolve symbol'. On pressing ALT + Enter, Android Studio suggested me to 'Add testng to classpath'.
I don't quite understand what's going on here. I thought I don't need testng for what I'm trying to do here, nor the 2 articles above also didn't mention anything about testng.
Furthermore if I followed the Android Studio suggestion to 'Add testng to classpath', Android Studio will automatically add
androidTestCompile 'org.testng:testng:6.9.6'
in my gradle. And when I try to run the test, I will get the error
Error:Error converting bytecode to dex:
Cause: com.android.dex.DexException: Multiple dex files define Lorg/hamcrest/Description;