AndroidJUnit4 Should have a public constructor

Question

I'm trying to follow Android Developer Docs to write an Instrumented Unit Test, but, of course, it doesn't work. I am getting the error:

Custom runner class AndroidJUnit4 should have a public constructor with signature AndroidJUnit4(Class testClass)

when ever I run my example test:

package com.devetry.ytp

import android.content.Context
import android.support.test.InstrumentationRegistry
import android.support.test.rule.ActivityTestRule
import android.support.test.runner.AndroidJUnit4
import androidx.test.filters.LargeTest
import org.junit.Before
import org.junit.Test
import org.junit.runner.RunWith

import androidx.test.runner.AndroidJUnitRunner
import org.junit.Assert
import org.junit.Rule

@RunWith(AndroidJUnit4::class)
class ExampleAndroidTest {

    /**
     * VARIABLES
     */



    /**
     * LIFE CYCLE
     */


    /**
     * Example Android Test
     *
     * An example android test
     */
    @Test
    fun exampleAndroidTest() {
        val context = InstrumentationRegistry.getTargetContext()
        Assert.assertEquals("com.devetry.ytp", context.packageName)
    }

}

I have tried tried multiple solutions to this specific error I found online, but like most things Android, the solution was either outdated or just simply didn't work. Unfortunately, of all of the solutions, I was unable to even recognize a common theme, thus leaving me stranded.

How can I resolve the error and just get an Instrumented Unit Tests to run?

@Pavneet_Singh yup, tried both of those. My Instrumented Test is in the AndroidTest folder and my configuration looks exactly the same... — BlondeSwan, Nov 21 '18 at 17:34

ggaier · Answer 1 · 2019-06-09T06:08:08.657

package com.devetry.ytp

import android.content.Context
import android.support.test.InstrumentationRegistry
import android.support.test.rule.ActivityTestRule
import android.support.test.runner.AndroidJUnit4
import androidx.test.filters.LargeTest
import org.junit.Before
import org.junit.Test
import org.junit.runner.RunWith

// AndroidJunitRunner and AndroidJUnit4 are not from the same pacakge
import androidx.test.runner.AndroidJUnitRunner
import org.junit.Assert
import org.junit.Rule

@RunWith(AndroidJUnit4::class)
class ExampleAndroidTest {

    /**
     * VARIABLES
     */



    /**
     * LIFE CYCLE
     */
...
}

You are not using the classes from the same package, make sure they are consistent. The support test package is conflict with androidx package.

Please consider copying, pasting and properly formatting any code that you include in your example, rather than use images of character data. — chb, Jun 09 '19 at 04:23

AndroidJUnit4 Should have a public constructor

1 Answers1