Add unit tests for FontManager

app/src/test/java/com/d4rk/androidtutorials/java/utils/FontManagerTest.java

@@ -0,0 +1,87 @@
+package com.d4rk.androidtutorials.java.utils;
+
+import static org.junit.Assert.assertSame;
+import static org.mockito.Mockito.inOrder;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.graphics.Typeface;
+
+import androidx.core.content.res.ResourcesCompat;
+
+import com.d4rk.androidtutorials.java.R;
+
+import org.junit.Test;
+import org.mockito.InOrder;
+import org.mockito.MockedStatic;
+import org.mockito.Mockito;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+public class FontManagerTest {
+
+    @Test
+    public void getMonospaceFont_returnsExpectedTypefaceForStoredValues() {
+        Context context = mock(Context.class);
+        when(context.getString(R.string.key_monospace_font)).thenReturn("monospace_font");
+
+        Map<String, Integer> values = new LinkedHashMap<>();
+        values.put("0", R.font.font_audiowide);
+        values.put("1", R.font.font_fira_code);
+        values.put("2", R.font.font_jetbrains_mono);
+        values.put("3", R.font.font_noto_sans_mono);
+        values.put("4", R.font.font_poppins);
+        values.put("5", R.font.font_roboto_mono);
+        values.put("6", R.font.font_google_sans_code);
+
+        for (Map.Entry<String, Integer> entry : values.entrySet()) {
+            SharedPreferences prefs = mock(SharedPreferences.class);
+            when(prefs.getString("monospace_font", "6")).thenReturn(entry.getKey());
+            Typeface expectedTypeface = mock(Typeface.class);
+
+            try (MockedStatic<ResourcesCompat> resourcesStatic = Mockito.mockStatic(ResourcesCompat.class)) {
+                resourcesStatic.when(() -> ResourcesCompat.getFont(context, entry.getValue()))
+                        .thenReturn(expectedTypeface);
+
+                Typeface result = FontManager.getMonospaceFont(context, prefs);
+
+                assertSame("Unexpected typeface for value " + entry.getKey(), expectedTypeface, result);
+                verify(prefs).getString("monospace_font", "6");
+                resourcesStatic.verify(() -> ResourcesCompat.getFont(context, entry.getValue()));
+            }
+        }
+    }
+
+    @Test
+    public void getMonospaceFont_removesInvalidPreferenceValueAndReturnsDefaultFont() {
+        Context context = mock(Context.class);
+        SharedPreferences prefs = mock(SharedPreferences.class);
+        SharedPreferences.Editor editor = mock(SharedPreferences.Editor.class);
+
+        when(context.getString(R.string.key_monospace_font)).thenReturn("monospace_font");
+        when(prefs.edit()).thenReturn(editor);
+        when(editor.remove("monospace_font")).thenReturn(editor);
+        when(prefs.getString("monospace_font", "6")).thenThrow(new ClassCastException("Expected string"));
+
+        Typeface defaultTypeface = mock(Typeface.class);
+
+        try (MockedStatic<ResourcesCompat> resourcesStatic = Mockito.mockStatic(ResourcesCompat.class)) {
+            resourcesStatic.when(() -> ResourcesCompat.getFont(context, R.font.font_google_sans_code))
+                    .thenReturn(defaultTypeface);
+
+            Typeface result = FontManager.getMonospaceFont(context, prefs);
+
+            assertSame(defaultTypeface, result);
+            verify(prefs).getString("monospace_font", "6");
+            verify(prefs).edit();
+            InOrder inOrder = inOrder(editor);
+            inOrder.verify(editor).remove("monospace_font");
+            inOrder.verify(editor).apply();
+            resourcesStatic.verify(() -> ResourcesCompat.getFont(context, R.font.font_google_sans_code));
+        }
+    }
+}