UInt and UByte return values cannot be mocked in suspending functions

[david-livefront]

Prerequisites

• I am running the latest version
• I checked the documentation and found no answer
• I checked to make sure that this issue has not already been filed

Expected Behavior

When I create a mock for a Kotlin class, I should be able to mock a UInt or UByte response on a suspending function.

Current Behavior

The mock will return a Java Integer or Java Byte instead of the appropriate Kotlin unsigned type, this causes type mismatches and can lead to a ClassCastException.

Context

MockK version: 1.13.11
OS: MacOS Sonoma 14.4.1
Kotlin version: 1.9.24
JDK version: openjdk-17
JUnit version: 5.10.2
Type of test: unit test

Minimal reproducible code (the gist of this issue)

Note that removing the suspend keyword from the bar() function causes this test to pass.

    interface Foo {
        suspend fun bar(): UByte
    }

    @Test
    fun `mock Ubyte`() = runBlocking {
        val result: UByte = 5u
        val mock = mockk<Foo> {
            coEvery { bar() } returns result
        }

       assertEquals(result, mock.bar())
    }