Can't initialize lateinit property (class) properly in test using Mockito

Question

Class using "context"

So in MainActivity.kt everything is great

But in test it doesn't work

package com.example.testwork

import org.junit.Assert
import org.junit.Test

class PrefManagerTest {

    lateinit var prefManager: PrefManager

    @Test
    fun getUsername() {
        prefManager = PrefManager(this)
        prefManager.setUsername("name")
        Assert.assertEquals("name", prefManager.getUsername())
    }
}

In general I'm trying to test my function in PrefManager.kt, which gives name PrefManager.kt

package com.example.testwork

import android.content.Context
import android.content.SharedPreferences

class PrefManager(context: Context?) {
    //Shared Pref Mode
    val PRIVATE_MODE: Int = 0

    //SharedPref FileName
    private  val PREF_NAME: String? = "SharedPreferences"
    private val IS_LOGIN: String? = "is_login"


    val pref: SharedPreferences? = context?.getSharedPreferences(PREF_NAME, PRIVATE_MODE)
    val editor: SharedPreferences.Editor? = pref?.edit()

    fun setUsername(username: String?){
        editor?.putString("username", username)
        editor?.commit()
    }

    fun getUsername(): String?{
        return pref?.getString("username", "")
    }

}

Answer 1

Please try this

1. Java:

   Context context = mock(Context.class);

2. Kotlin:

   mock(Context::class.java)

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