android_test_setup.md

Quick-start guide: writing JVM/Robolectric unit tests for this repo

0. Where tests live
   • Path: app/src/test/java/com/limelight/... (plain JVM tests, not instrumented).
   • Build task:
   – Default flavour: ./gradlew :app:testNonRoot_gameDebugUnitTest
   – Root flavour: ./gradlew :app:testRootDebugUnitTest
   – All: ./gradlew :app:testDebugUnitTest

1. Dependencies & Gradle switches
   app/build.gradle already contains everything you need:

   testImplementation 'junit:junit:4.13.2'
   testImplementation 'androidx.test:core:1.5.0'
   testImplementation 'org.robolectric:robolectric:4.11.1'
   testImplementation 'org.mockito:mockito-core:5.11.0'
   

   Extra flag:

   testOptions.unitTests.includeAndroidResources = true  
   

   → Tells Robolectric to merge res/ into the unit-test APK so layout inflation works.

2. Test-class boilerplate

   @Config(sdk = {33},
           shadows = {
               com.limelight.shadows.ShadowMoonBridge.class,
               com.limelight.shadows.ShadowGameManager.class})
   @RunWith(RobolectricTestRunner.class)
   public class MyFeatureTest {
       private Context ctx;
   
       @BeforeClass
       public static void silenceLogs() {
           TestLogSuppressor.install();   // hides noisy “Invalid ID 0x00000000” spam
       }
   
       @Before
       public void setUp() {
           ctx = ApplicationProvider.getApplicationContext();
           // extra prep (clear prefs, reset singletons, etc.)
       }
   
       @Test
       public void something_should_work() {
           /* your assertions */
       }
   }

   • @Config(sdk = {33}) makes Robolectric emulate Android 13 (matches compileSdk 34 while staying stable).
   • shadows = … suppresses native or platform calls:

   – ShadowMoonBridge eliminates the static initializer that tries System.loadLibrary("moonbr"), and provides minimal stubs/constants used by the app.
   – ShadowGameManager avoids a ServiceManager lookup present on real devices.

   If you hit another native/SDK obstacle, create a new shadow the same way:

   @Implements(SomeProblematicClass.class)
   public class ShadowFoo {
       @Implementation protected static void __staticInitializer__() {}
   }

3. Typical helpers used in current tests

   • Resetting singletons – many app classes use private static caches.
   Example (ProfilesManager):

   Field f = ProfilesManager.class.getDeclaredField("instance");
   f.setAccessible(true);
   f.set(null, null);       // clear before each test

   • Cleaning filesystem state – tests create/delete context.getFilesDir()/profiles.
   Re-use deleteRecursively(File) from existing tests.

   • Preferences isolation – wipe them in @Before:

   SharedPreferences p = PreferenceManager.getDefaultSharedPreferences(ctx);
   p.edit().clear().commit();

   • Activity testing – use the Robolectric buildActivity chain:

   MyActivity act = Robolectric.buildActivity(MyActivity.class)
                               .create().start().resume().get();
   assertFalse(act.isFinishing());

   • Intent extras check: supply them directly to buildActivity.
   • Configuration changes: call activity.onConfigurationChanged(newConfig) manually.
   • Low-memory / lifecycle: activity.onLowMemory(), activity.onDestroy(), etc.

4. Mockito (rarely used yet)
   If a new test needs mocks (e.g. for NvConnection), just:

   NvConnection conn = Mockito.mock(NvConnection.class);
   Mockito.when(conn.sendUtf8Text(Mockito.anyString())).thenReturn(0);

5. Tips & Gotchas specific to this project

   • Native JNI classes (MoonBridge, etc.) must always be shadowed or the test JVM will UnsatisfiedLinkError.
   • GameManager & BackdropFrameRenderer are Android-T APIs; stubbing them prevents ServiceManager or SurfaceFlinger lookups.
   • Resources – because includeAndroidResources=true, you can safely inflate real layout XML, but keep the SDK level in @Config ≥ the latest attribute you reference.
   • Product flavours – tests are compiled once per flavour; don’t hard-code BuildConfig.APPLICATION_ID, use context.getPackageName() when needed.
   • Suppress noisy log spam – call TestLogSuppressor.install() once per test-class (see above).

6. Skeleton for a new test file

   app/
     src/
       test/
         java/
           com/
             limelight/
               myfeature/
                 AwesomeFeatureTest.java   <-- new
   

   package com.limelight.myfeature;
   
   import android.content.Context;
   import androidx.test.core.app.ApplicationProvider;
   import com.limelight.TestLogSuppressor;
   import org.junit.*;
   import org.robolectric.*;
   import org.robolectric.annotation.Config;
   
   @Config(sdk = {33},
           shadows = {com.limelight.shadows.ShadowMoonBridge.class,
                      com.limelight.shadows.ShadowGameManager.class})
   @RunWith(RobolectricTestRunner.class)
   public class AwesomeFeatureTest {
       private Context ctx;
   
       @BeforeClass
       public static void init() { TestLogSuppressor.install(); }
   
       @Before
       public void setUp() { ctx = ApplicationProvider.getApplicationContext(); }
   
       @Test
       public void newFeature_doesSomething() {
           // Arrange
   
           // Act
   
           // Assert
           Assert.assertTrue(true);
       }
   }

With the above conventions—Robolectric runner, shadows for native pieces, reflection resets, and resource-enabled unit tests—you can write new coverage quickly without needing the Android emulator or androidTest instrumentation.

    @Config(sdk = {33},
            shadows = {
                com.limelight.shadows.ShadowMoonBridge.class,
                com.limelight.shadows.ShadowGameManager.class})
    @RunWith(RobolectricTestRunner.class)
    public class MyFeatureTest {
        private Context ctx;

        @BeforeClass
        public static void silenceLogs() {
            TestLogSuppressor.install();   // hides noisy “Invalid ID 0x00000000” spam
        }

        @Before
        public void setUp() {
            ctx = ApplicationProvider.getApplicationContext();
            // extra prep (clear prefs, reset singletons, etc.)
        }

        @Test
        public void something_should_work() {
            /* your assertions */
        }
    }

    @Implements(SomeProblematicClass.class)
    public class ShadowFoo {
        @Implementation protected static void __staticInitializer__() {}
    }

      Field f = ProfilesManager.class.getDeclaredField("instance");
      f.setAccessible(true);
      f.set(null, null);       // clear before each test

      SharedPreferences p = PreferenceManager.getDefaultSharedPreferences(ctx);
      p.edit().clear().commit();

      MyActivity act = Robolectric.buildActivity(MyActivity.class)
                                  .create().start().resume().get();
      assertFalse(act.isFinishing());

    NvConnection conn = Mockito.mock(NvConnection.class);
    Mockito.when(conn.sendUtf8Text(Mockito.anyString())).thenReturn(0);

    app/
      src/
        test/
          java/
            com/
              limelight/
                myfeature/
                  AwesomeFeatureTest.java   <-- new

    package com.limelight.myfeature;

    import android.content.Context;
    import androidx.test.core.app.ApplicationProvider;
    import com.limelight.TestLogSuppressor;
    import org.junit.*;
    import org.robolectric.*;
    import org.robolectric.annotation.Config;

    @Config(sdk = {33},
            shadows = {com.limelight.shadows.ShadowMoonBridge.class,
                       com.limelight.shadows.ShadowGameManager.class})
    @RunWith(RobolectricTestRunner.class)
    public class AwesomeFeatureTest {
        private Context ctx;

        @BeforeClass
        public static void init() { TestLogSuppressor.install(); }

        @Before
        public void setUp() { ctx = ApplicationProvider.getApplicationContext(); }

        @Test
        public void newFeature_doesSomething() {
            // Arrange

            // Act

            // Assert
            Assert.assertTrue(true);
        }
    }