mockito, in koltin how to verify a static method

Issue

Having a kotlin singleton static method

internal object TestSingleton {
    @JvmStatic
    fun staticMethod1 (str: String) {
        println("+++ === +++ TestSingleton.staticMethod(), $str")
        staticMethod2 (str)
    }

    @JvmStatic
    fun staticMethod2 (str: String) {
        println("+++ === +++ TestSingleton.staticMethod2(), $str")
    }
}

In java test code:

    @Test
    public void test_staticMethod() {

        try (MockedStatic<TestSingleton> theMock = Mockito.mockStatic(TestSingleton.class, CALLS_REAL_METHODS)) {

            TestSingleton.staticMethod1("test");
            theMock.verify(() -> TestSingleton.staticMethod2(eq("test")), times(1));
        }
    }

it runs fine but convert to kotlin it does not compile:

    @Test
    open fun test_staticMethod() {
        Mockito.mockStatic(TestSingleton::class.java, Mockito.CALLS_REAL_METHODS).use { theMock ->
            staticMethod1("test")

            theMock.verify(() -> TestSingleton.staticMethod(any(Context.class), "test"), times(1))
            // or
            theMock.verify(times(1), () -> TestSingleton.staticMethod(any(Context.class)) )

        }
    }

having mockito version testImplementation "org.mockito:mockito-inline:3.12.4".

How to test static method using mockito in kotlin? Not tried mockk yet since having a lot tests have been working with mockito. Not sure how simple with mockk in this case.

Solution

Here's how to do it in mockk (I highly recommend switching away from Mockito, mockk is just so much easier):

import TestSingleton.staticMethod1
import io.mockk.every
import io.mockk.just
import io.mockk.mockkStatic
import io.mockk.runs
import io.mockk.verify
import org.junit.jupiter.api.Test

internal object TestSingleton {
    @JvmStatic
    fun staticMethod1(str: String) {
        println("+++ === +++ TestSingleton.staticMethod(), $str")
        staticMethod2(str)
    }

    @JvmStatic
    fun staticMethod2(str: String) {
        println("+++ === +++ TestSingleton.staticMethod2(), $str")
    }
}

class StackSign {

    @Test
    fun test_staticMethod() {

        mockkStatic(TestSingleton::class)
        every { TestSingleton.staticMethod2("test") } just runs
        staticMethod1("test")
        verify(exactly = 1) { TestSingleton.staticMethod2("test") }
    }
}

BTW, add this to your build.gradle.kts

testImplementation("io.mockk:mockk:1.12.3")

Answered By - PaulNUK