BaseRetrofitEnqueue.kt

package com.example.network

import android.util.Log
import retrofit2.Call
import retrofit2.Callback
import retrofit2.Response
import com.example.utils.ErrorUtils

/**
 * Extension for awaitResponse
 */
fun <T : Any> Call<T>.awaitResponse(
        onSuccess: (T?) -> Unit = {},
        onError: (String, Int) -> Unit = { _, _ -> },
        onFailure: (Call<T>, String?) -> Unit = { _, _ -> }
) {
    // Extension for Enqueue
    this.enqueue(object : Callback<T> {
        val TAG = "BaseRetrofitEnqueue"

        /**
         * OnResponse Callback
         */
        override fun onResponse(call: Call<T>, response: Response<T>) {
            if (response.isSuccessful) {
                onSuccess.invoke(response.body())
            } else {
                val error = ErrorUtils.parseGenericError(response)  //Parsing the error in case you need the error message
                Log.d(TAG, "Error: ${error.message()} With response code ${response.code()}")
                onError.invoke(error.message(), response.code())  // In case you want to handle 403,404 errors.
            }
        }

        /**
         * OnFailure Callback
         */
        override fun onFailure(call: Call<T>, t: Throwable) {
            onFailure.invoke(call, t.message)
        }
    })
}

// ErrorUtils class

package com.example.utils

import retrofit2.Response

class ErrorUtils {

companion object {

    /**
     * Parse a generic Error
     */
    fun <T: Any> parseGenericError(response: Response<T>): Response<T> {
        return response
    }
}

}