Support testing for resource shrinking

Add a simple test and add necessary mock dependencies to allow future
resoure shrinking use with platform targets.

Test: m
Bug: 202959019
Change-Id: Id2dd44d52ce5ea62c06784caab0af6276248cb3f

java/Android.bp

@@ -101,6 +101,7 @@ bootstrap_go_package {
         "plugin_test.go",
         "prebuilt_apis_test.go",
         "proto_test.go",
+        "resourceshrinker_test.go",
         "rro_test.go",
         "sdk_test.go",
         "sdk_library_test.go",

java/dex.go

@@ -63,6 +63,7 @@ type DexProperties struct {
 		// classes referenced by the app manifest.  Defaults to false.
 		No_aapt_flags *bool
 
+		// If true, optimize for size by removing unused resources. Defaults to false.
 		Shrink_resources *bool
 
 		// Flags to pass to proguard.

java/resourceshrinker_test.go

@@ -0,0 +1,53 @@
+// Copyright 2022 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package java
+
+import (
+	"testing"
+
+	"android/soong/android"
+)
+
+func TestShrinkResourcesArgs(t *testing.T) {
+	result := android.GroupFixturePreparers(
+		PrepareForTestWithJavaDefaultModules,
+	).RunTestWithBp(t, `
+		android_app {
+			name: "app_shrink",
+			platform_apis: true,
+			optimize: {
+				shrink_resources: true,
+			}
+		}
+
+		android_app {
+			name: "app_no_shrink",
+			platform_apis: true,
+			optimize: {
+				shrink_resources: false,
+			}
+		}
+	`)
+
+	appShrink := result.ModuleForTests("app_shrink", "android_common")
+	appShrinkResources := appShrink.Rule("shrinkResources")
+	android.AssertStringDoesContain(t, "expected shrinker.xml in app_shrink resource shrinker flags",
+		appShrinkResources.Args["raw_resources"], "shrinker.xml")
+
+	appNoShrink := result.ModuleForTests("app_no_shrink", "android_common")
+	if appNoShrink.MaybeRule("shrinkResources").Rule != nil {
+		t.Errorf("unexpected shrinkResources rule for app_no_shrink")
+	}
+}

java/testing.go

@@ -74,6 +74,7 @@ var prepareForTestWithFrameworkDeps = android.GroupFixturePreparers(
 		// Needed for R8 rules on apps
 		"build/make/core/proguard.flags":             nil,
 		"build/make/core/proguard_basic_keeps.flags": nil,
+		"prebuilts/cmdline-tools/shrinker.xml":       nil,
 	}.AddToFixture(),
 )