Mocking external function or variable throws UnsatisifiedLinkError

[olllo123]

Expected Behavior

Mocking external methods and variables works

Current Behavior

Trying to mock external method or variable causes UnsatisifiedLinkError being thrown.

Failure Information (for bugs)

Trying to provide mocked behaviour for any method or variable marked as external results in UnsatisifiedLinkError being thrown. Although there is issue already reported here this one is connected with mocking simple Class mocking not Object.

Steps to Reproduce

Please provide detailed steps for reproducing the issue.

1. Create a simple class with external method:

class ClassWithExternalMethod {
    external fun someExternalCall()
    var listener: Any?
        external get
        external set
}

2. Create a test method mocking above

class TestClass {
    
    @Test
    fun test(){
        val mock: ClassWithExternalMethod = mockk {
            every { someExternalCall() } just Runs
        }
        mock.someExternalCall()
    }
    
}

4. Run the test above.

Context

Please provide any relevant information about your setup. This is important in case the issue is not reproducible except for under certain conditions.

• MockK version: 1.13.4
• OS: Mac
• Kotlin version: 1.7.20
• JDK version: 1.8
• JUnit version: JUnit 4
• Type of test: Unit

Stack trace

'void com.test.android.common.ClassWithExternalMethod.someExternalCall()'
java.lang.UnsatisfiedLinkError: 'void com.test.android.common.ClassWithExternalMethod.someExternalCall()'
	at com.test.android.common.ClassWithExternalMethod.someExternalCall(Native Method)

[stevepham]

any update for this issue? I tried to mockStatic System and mock method loadLibrary but seems it causes another issue when mock System class

[rfermontero]

The same, looking for a solution.

[olllo123]

I did find a workaround though.

Create a class eg. FakeClassWithExternalMethod that inherits from ClassWithExternalMethod

In it's implementation override all the external methods of base class so super.someExternalMethod is not called.

Then when mocking use instance of FakeClassWithExternalMethod instead of ClassWithExternalMethod