Prerequisites

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• 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

Steps to Reproduce

When using a value class with init {} validation, such as this example:

@JvmInline value class MyToken(val raw: String) {
  init { require(raw.startsWith("MY_PREFIX::")) }
}

Then a mock such as this

@Test
fun `should work with value classes`() {
  registerInstanceFactory {
    println("called")
    MyToken("MY_PREFIX::bar")
  }
  val userOfMyToken = mockk<UserOfMyToken>()
  every { userOfMyToken.useMyToken(any()) } returns Unit
}

interface UserOfMyToken {
  fun useMyToken(myToken: MyToken)
}

Then "called" is not logged, and the test fails with an IllegalArgumentException on the init's require().

But if I just change the value class to a data class:

data class MyToken(val raw: String) {
  init { require(raw.startsWith("MY_PREFIX::")) }
}

Then "called" is logged, and the the test passes. And using withInstanceFactory instead of registerInstanceFactory produces the same result.