Test run failed: Instrumentation run failed due to 'java.lang.ClassNotFoundException'

Question

This is my first time setting up an Android test project to test a Android project.

I've created a very basic test case which I'm trying to get to run, however what I have does not run. I get a Test run failed: Instrumentation run failed due to 'java.lang.ClassNotFoundException'.

I would troubleshot this more, however I don't get any more information, such as which class it is trying to find, etc. Any ideas on how to get more information from the error? Any common areas I should look at, or anything that might need to be configured that I'm overlooking?

Below is the information from the console:

[2013-04-16 13:21:49 - XyzProgramTest] Android Launch!
[2013-04-16 13:21:49 - XyzProgramTest] adb is running normally.
[2013-04-16 13:21:49 - XyzProgramTest] Performing android.test.InstrumentationTestRunner JUnit launch
[2013-04-16 13:21:49 - XyzProgramTest] Automatic Target Mode: launching new emulator with compatible AVD 'GalaxyNexusAPI_17'
[2013-04-16 13:21:49 - XyzProgramTest] Launching a new emulator with Virtual Device 'GalaxyNexusAPI_17'
[2013-04-16 13:21:53 - Emulator] extension WGL_ARB_make_current_read was not found
[2013-04-16 13:21:53 - Emulator] extension WGL_EXT_swap_control was not found
[2013-04-16 13:21:53 - Emulator] Failed to create pbuf surface for FB 0x3004
[2013-04-16 13:21:53 - Emulator] emulator: WARNING: Could not initialize OpenglES emulation, using software renderer.
[2013-04-16 13:21:54 - XyzProgramTest] New emulator found: emulator-5554
[2013-04-16 13:21:54 - XyzProgramTest] Waiting for HOME ('android.process.acore') to be launched...
[2013-04-16 13:22:55 - XyzProgramTest] HOME is up on device 'emulator-5554'
[2013-04-16 13:22:55 - XyzProgramTest] Uploading XyzProgramTest.apk onto device 'emulator-5554'
[2013-04-16 13:22:55 - XyzProgramTest] Installing XyzProgramTest.apk...
[2013-04-16 13:23:57 - XyzProgramTest] Success!
[2013-04-16 13:23:57 - XyzProgramTest] Project dependency found, installing: XyzProgram
[2013-04-16 13:23:57 - XyzProgram] Uploading XyzProgram.apk onto device 'emulator-5554'
[2013-04-16 13:23:58 - XyzProgram] Installing XyzProgram.apk...
[2013-04-16 13:24:05 - XyzProgram] Success!
[2013-04-16 13:24:05 - XyzProgramTest] Launching instrumentation android.test.InstrumentationTestRunner on emulator-5554
[2013-04-16 13:24:07 - XyzProgramTest] Test run failed: Instrumentation run failed due to 'java.lang.ClassNotFoundException'

Additional Notes

In my Android test project, I created a simple test with a package similar to the package that matches up with the class I'm trying to test in my Android project. So something like com.company.android.projectname. I've specified this in the Android test project manifest file's instrumentation section.

<instrumentation
    android:name="android.test.InstrumentationTestRunner"
    android:targetPackage="com.company.android.projectname" />

When I changed this to match that, I get a new error that says Test run failed: Unable to find instrumentation target package: com.company.android.projectname

I'm not 100% sure what that targetPackage should be and if I need multiple instrumentations for each package I want to test, etc. When I set it to com.company.android that is when I get the java.lang.ClassNotFoundException.

Answer 1

I had upgraded to androidx libraries and started getting this error.

To fix it, in build.gradle I changed the line:

testInstrumentationRunner 'android.support.test.runner.AndroidJUnitRunner'

to

testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"

Answer 2

FYI I ran into this and had to add

<uses-library android:name="android.test.runner"/>

within my <application/> tag

Answer 3

In my case, I was trying to run the tests on Jelly Bean emulator. Android instrumentation does not seem to support Jelly Bean. I could run the tests on lollipop.

You may also not able to run android tests through release build type. Ensure that debug build type is active.

Answer 4

Figured out my issue and am posting the answer for documentation purposes...

The root of my problem was 2 different things:

1. I did some refactoring, which change the location of my android.app.Application class and my activities. This made it so my main program was not working as I needed to update my manifest in my android project.
2. After making the updates to my manifest in my android project, I had to make some updates in my android test project to point to the updated location of the class that extends android.app.Application.

After that, did some cleans and tested again and things were good.

Answer 5

I got the same error because I forgot to add androidx.test:runner test dependency.

androidTestImplementation "androidx.test:runner:1.2.0"