Parameterized JUnit4 test example in Kotlin

ParameterizedKotlinTest.kt

@RunWith(Parameterized::class)
class KotlinTest(val paramOne: Int, val paramTwo: String) {

    companion object {
        @JvmStatic
        @Parameterized.Parameters
        fun data() : Collection<Array<Any>> {
            return listOf(
                    arrayOf(1, "I"),         // First test:  (paramOne = 1, paramTwo = "I")
                    arrayOf(1999, "MCMXCIX") // Second test: (paramOne = 1999, paramTwo = "MCMXCIX")
            )
        }
    }

    @Test
    fun shouldReturnExpectedRomanForArabic() {
        assertThat(RomanNumeralGenerator().arabicToRoman(paramOne), equalTo(paramTwo));
    }
}

Thanks for this! It gave me the right direction.
Here is my variation of it using Kotlin's expression body:

@RunWith(Parameterized::class)
class KotlinParameterizedTest(private val paramOne: Int, private val paramTwo: String) {

    private val underTest = RomanNumeralGenerator()

    companion object {
        @JvmStatic
        @Parameterized.Parameters
        fun data() = listOf(
                arrayOf(1, "I"),         // First test:  (paramOne = 1, paramTwo = "I")
                arrayOf(1999, "MCMXCIX") // Second test: (paramOne = 1999, paramTwo = "MCMXCIX")
        )
    }

    @Test
    fun shouldReturnExpectedRomanForArabic() {
        assertThat(underTest.arabicToRoman(paramOne), equalTo(paramTwo));
    }

}

Thanks for this! It gave me the right direction.
Here is my variation of it using Kotlin's expression body:

@RunWith(Parameterized::class)
class KotlinParameterizedTest(private val paramOne: Int, private val paramTwo: String) {

    private val underTest = RomanNumeralGenerator()

    companion object {
        @JvmStatic
        @Parameterized.Parameters
        fun data() = listOf(
                arrayOf(1, "I"),         // First test:  (paramOne = 1, paramTwo = "I")
                arrayOf(1999, "MCMXCIX") // Second test: (paramOne = 1999, paramTwo = "MCMXCIX")
        )
    }

    @Test
    fun shouldReturnExpectedRomanForArabic() {
        assertThat(underTest.arabicToRoman(paramOne), equalTo(paramTwo));
    }

}

Looks good!

Thanks for this ... just what i needed to know.

Is it possible to add multiple test method in the same class and test them against data ?

Is it possible to add multiple test method in the same class and test them against data ?

Sure!

holly crap, stumbled across this ;)
👋

holly crap, stumbled across this ;) 👋

holly molly, came across this 😉

Thanks, but i have a question here

After using the same code, the test runs twice with the same parameter

Any ideas how to prevent that from happening?

Thanks for this snippet 👍