ShadowResourcesCompat

BaseRobolectricUnitTest.kt

import com.ankushg.example.BuildConfig
import com.ankushg.example.shadows.ShadowResourcesCompat

import org.junit.runner.RunWith

import org.robolectric.RobolectricTestRunner
import org.robolectric.RuntimeEnvironment
import org.robolectric.Shadows
import org.robolectric.annotation.Config

@RunWith(RobolectricTestRunner::class)
@Config(
    constants = BuildConfig::class,
    packageName = "com.ankushg.example",
    sdk = intArrayOf(21),
    shadows = arrayOf(
        ShadowResourcesCompat::class
    )
)
abstract class BaseRobolectricTest {
    // common code here
}

ShadowResourcesCompat.java

package com.ankushg.example.shadows;

import android.content.Context;
import android.graphics.Typeface;
import android.support.annotation.FontRes;
import android.support.annotation.NonNull;
import android.support.v4.content.res.ResourcesCompat;
import java.util.HashMap;
import java.util.Map;
import org.robolectric.annotation.Implementation;
import org.robolectric.annotation.Implements;

/**
 * Mocks out ResourcesCompat so getFont won't actually attempt to look up the FontRes as a real
 * resource, because of issues with Robolectric.
 * <p>
 * See: https://github.com/robolectric/robolectric/issues/3590
 */
@Implements(ResourcesCompat.class) public class ShadowResourcesCompat {
    private static Map<Integer, Typeface> FONT_MAP = new HashMap<>();

    @Implementation
    public static Typeface getFont(@NonNull Context context, @FontRes int id) {
        return FONT_MAP.computeIfAbsent(id, ShadowResourcesCompat::buildTypeface);
    }

    private static Typeface buildTypeface(@FontRes int id) {
        return Typeface.DEFAULT;
    }
}