Add unit tests for CompositeBackgroundDrawable layer ordering optimization (#47913)

Summary:
Pull Request resolved: #47913

CompositeBackgroundDrawable has some logic for inserting the layers that are not set through the constructor. This unit test makes sure they are being properly ordered.

Changelog: [Internal]

Reviewed By: NickGerleman

Differential Revision: D66381515

fbshipit-source-id: 514979a4a97fa159c1d1c3c923afe969eafc21c3

Author: jorge-cab

packages/react-native/ReactAndroid/src/test/java/com/facebook/react/uimanager/CompositeBackgroundDrawableTest.kt

@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.react.uimanager
+
+import android.annotation.TargetApi
+import android.content.Context
+import android.graphics.Color
+import android.graphics.drawable.LayerDrawable
+import com.facebook.react.common.annotations.UnstableReactNativeAPI
+import com.facebook.react.internal.featureflags.ReactNativeFeatureFlags
+import com.facebook.react.uimanager.drawable.BackgroundDrawable
+import com.facebook.react.uimanager.drawable.BorderDrawable
+import com.facebook.react.uimanager.drawable.CompositeBackgroundDrawable
+import com.facebook.react.uimanager.drawable.InsetBoxShadowDrawable
+import com.facebook.react.uimanager.drawable.OutlineDrawable
+import com.facebook.react.uimanager.drawable.OutsetBoxShadowDrawable
+import com.facebook.react.uimanager.style.OutlineStyle
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.MockedStatic
+import org.mockito.Mockito.mockStatic
+import org.robolectric.RobolectricTestRunner
+import org.robolectric.RuntimeEnvironment
+
+@TargetApi(29)
+@OptIn(UnstableReactNativeAPI::class)
+@RunWith(RobolectricTestRunner::class)
+class CompositeBackgroundDrawableTest {
+
+  private val ctx: Context = RuntimeEnvironment.getApplication()
+  private lateinit var rnFeatureFlags: MockedStatic<ReactNativeFeatureFlags>
+
+  @Before
+  fun setup() {
+    rnFeatureFlags = mockStatic(ReactNativeFeatureFlags::class.java)
+    rnFeatureFlags
+        .`when`<Boolean> { ReactNativeFeatureFlags.enableNewBackgroundAndBorderDrawables() }
+        .thenReturn(true)
+  }
+
+  @Test
+  fun testCompositeBackgroundDrawableLayerOrdering() {
+
+    val background = BackgroundDrawable(ctx)
+    val outerShadows =
+        LayerDrawable(arrayOf(OutsetBoxShadowDrawable(ctx, Color.BLACK, 1f, 1f, 0f, 1f)))
+    val innerShadows =
+        LayerDrawable(arrayOf(InsetBoxShadowDrawable(ctx, Color.BLACK, 1f, 1f, 0f, 1f)))
+    val border = BorderDrawable(ctx, null, null, null, null)
+    val outline =
+        OutlineDrawable(
+            ctx,
+            outlineColor = Color.BLACK,
+            outlineOffset = 0f,
+            outlineStyle = OutlineStyle.SOLID,
+            outlineWidth = 1f)
+
+    /** Create CompositeBackgroundDrawable with constructor */
+    val control =
+        CompositeBackgroundDrawable(
+            context = ctx,
+            outerShadows = outerShadows,
+            background = background,
+            border = border,
+            innerShadows = innerShadows,
+            outline = outline)
+
+    /**
+     * Create CompositeBackgroundDrawable with shuffled method functions (triggers layer ordering
+     * logic)
+     */
+    val test = CompositeBackgroundDrawable(ctx)
+    test.withNewInnerShadow(innerShadows)
+    test.withNewOuterShadow(outerShadows)
+    test.withNewBorder(border)
+    test.withNewOutline(outline)
+    test.withNewBackground(background)
+
+    /** Verify that the two CompositeBackgroundDrawables are equivalent */
+    assertThat(test.getDrawable(0)).isEqualTo(control.getDrawable(0))
+    assertThat(test.getDrawable(1)).isEqualTo(control.getDrawable(1))
+    assertThat(test.getDrawable(2)).isEqualTo(control.getDrawable(2))
+    assertThat(test.getDrawable(3)).isEqualTo(control.getDrawable(3))
+    assertThat(test.getDrawable(4)).isEqualTo(control.getDrawable(4))
+  }
+}