mockito-kotlin | Using Mockito with Kotlin | Unit Testing library

My Gradle couldn't find the redacted-gradle-plugin but both of your classes compiles with this minimalistic build.gradle.kts:

With the below dependencies I was able to build project successfully:

Personally I'm not a fan of mocks. If Sdk is an interface, you could just provide your own test implementation to perform your tests (for success and error results). You can control exactly when/if the callback is called etc.

If Sdk is a class that you can't control, you could create an interface to abstract the Sdk class away, and make your initialize method use your own interface instead. However I have to admit this is not ideal.

If you stick with mocking, usually mocking libraries have a way for you to use invocation arguments to mock responses to method calls. With Mockito, it should be something like:

Using RobolectricTestRunner ,we can run the test that depends on the android framework without emulator or real device.

ViewModel is a android library.So to test the ViewModel need to add RobolectricTestRunner.

For that first add dependency

You can not verify that the extension function is called on your mock, as it is not part of that class. The extension function is just a top-level function with a receiver (in your case an instance of Metrics).

But you can still verify that the extension function was called in your code

You can do this using mockkStatic. You are passing the the path of the (generated) extension function. Let's assume you created your Metrics extension function in package org.com. The extension class should get generated in: com.org.MericsExtensionKt.

A test that wants to verify the call to your extension function could look like:

I took a look into your repository on github here. Here's what I've found.

Your first problem is that you mock out a ViewModel. So, when you simulate onResume for your Fragment it invokes:

Looks like you're creating an extension function on KotlinBuildScript which may or may not be the issue. Regardless, there's no need for extension functions since you can just use the DSL directly.

Gradle calls the shared build logic convention plugins: https://docs.gradle.org/current/samples/sample_convention_plugins.html#compiling_convention_plugins

So your Example.kt would become kotlin-conventions.gradle.kts:

android.arch is the namespace of pre-AndroidX Architecture Components. As you are using an AndroidX project, you need to use the androidx.arch.core version of those dependencies:

Finally got it to work with any of the Gradle versions, tried it with (5.6.x, 6.3, 6.4, 6.5 and 6.6).

The thing we were missing is updating the kotlin plugin.spring version. After we updated that to 1.3.72 instead of 1.3.50 everything was working as expected.