test: add unit tests for ad utils

app/src/test/java/com/d4rk/androidtutorials/java/ads/AdUtilsTest.java

@@ -0,0 +1,87 @@
+package com.d4rk.androidtutorials.java.ads;
+
+import static org.mockito.Mockito.*;
+
+import android.content.Context;
+import android.view.View;
+
+import com.d4rk.androidtutorials.java.ads.views.NativeAdBannerView;
+import com.google.android.gms.ads.AdRequest;
+import com.google.android.gms.ads.AdView;
+import com.google.android.gms.ads.MobileAds;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.MockedStatic;
+
+import java.lang.reflect.Field;
+
+/**
+ * Unit tests for {@link AdUtils}.
+ */
+public class AdUtilsTest {
+
+    @Before
+    public void setUp() throws Exception {
+        // Reset the initialized flag before each test
+        Field field = AdUtils.class.getDeclaredField("initialized");
+        field.setAccessible(true);
+        field.set(null, false);
+    }
+
+    @Test
+    public void initialize_callsMobileAdsInitializeOnlyOnce() {
+        Context context = mock(Context.class);
+        when(context.getApplicationContext()).thenReturn(context);
+
+        try (MockedStatic<MobileAds> mobileAds = mockStatic(MobileAds.class)) {
+            AdUtils.initialize(context);
+            AdUtils.initialize(context);
+
+            mobileAds.verify(() -> MobileAds.initialize(context), times(1));
+        }
+    }
+
+    @Test
+    public void loadBanner_withAdView_loadsAd() {
+        Context context = mock(Context.class);
+        when(context.getApplicationContext()).thenReturn(context);
+        AdView adView = mock(AdView.class);
+        when(adView.getContext()).thenReturn(context);
+
+        try (MockedStatic<MobileAds> mobileAds = mockStatic(MobileAds.class)) {
+            AdUtils.loadBanner(adView);
+            mobileAds.verify(() -> MobileAds.initialize(context));
+        }
+
+        verify(adView, times(1)).loadAd(any(AdRequest.class));
+    }
+
+    @Test
+    public void loadBanner_withNativeAdBannerView_loadsAd() {
+        Context context = mock(Context.class);
+        when(context.getApplicationContext()).thenReturn(context);
+        NativeAdBannerView nativeView = mock(NativeAdBannerView.class);
+        when(nativeView.getContext()).thenReturn(context);
+
+        try (MockedStatic<MobileAds> mobileAds = mockStatic(MobileAds.class)) {
+            AdUtils.loadBanner(nativeView);
+            mobileAds.verify(() -> MobileAds.initialize(context));
+        }
+
+        verify(nativeView, times(1)).loadAd();
+    }
+
+    @Test
+    public void loadBanner_withOtherView_doesNothing() {
+        Context context = mock(Context.class);
+        when(context.getApplicationContext()).thenReturn(context);
+        View view = mock(View.class);
+        when(view.getContext()).thenReturn(context);
+
+        try (MockedStatic<MobileAds> mobileAds = mockStatic(MobileAds.class)) {
+            AdUtils.loadBanner(view);
+            mobileAds.verifyNoInteractions();
+        }
+    }
+}