diff --git a/java/rro_test.go b/java/rro_test.go
new file mode 100644
index 0000000..345f2ee
--- /dev/null
+++ b/java/rro_test.go
@@ -0,0 +1,373 @@
+// Copyright 2020 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 (
+	"reflect"
+	"strings"
+	"testing"
+
+	"android/soong/android"
+)
+
+func TestRuntimeResourceOverlay(t *testing.T) {
+	fs := map[string][]byte{
+		"baz/res/res/values/strings.xml": nil,
+		"bar/res/res/values/strings.xml": nil,
+	}
+	bp := `
+		runtime_resource_overlay {
+			name: "foo",
+			certificate: "platform",
+			lineage: "lineage.bin",
+			product_specific: true,
+			static_libs: ["bar"],
+			resource_libs: ["baz"],
+			aaptflags: ["--keep-raw-values"],
+		}
+
+		runtime_resource_overlay {
+			name: "foo_themed",
+			certificate: "platform",
+			product_specific: true,
+			theme: "faza",
+			overrides: ["foo"],
+		}
+
+		android_library {
+			name: "bar",
+			resource_dirs: ["bar/res"],
+		}
+
+		android_app {
+			name: "baz",
+			sdk_version: "current",
+			resource_dirs: ["baz/res"],
+		}
+		`
+	config := testAppConfig(nil, bp, fs)
+	ctx := testContext(config)
+	run(t, ctx, config)
+
+	m := ctx.ModuleForTests("foo", "android_common")
+
+	// Check AAPT2 link flags.
+	aapt2Flags := m.Output("package-res.apk").Args["flags"]
+	expectedFlags := []string{"--keep-raw-values", "--no-resource-deduping", "--no-resource-removal"}
+	absentFlags := android.RemoveListFromList(expectedFlags, strings.Split(aapt2Flags, " "))
+	if len(absentFlags) > 0 {
+		t.Errorf("expected values, %q are missing in aapt2 link flags, %q", absentFlags, aapt2Flags)
+	}
+
+	// Check overlay.list output for static_libs dependency.
+	overlayList := m.Output("aapt2/overlay.list").Inputs.Strings()
+	staticLibPackage := buildDir + "/.intermediates/bar/android_common/package-res.apk"
+	if !inList(staticLibPackage, overlayList) {
+		t.Errorf("Stactic lib res package %q missing in overlay list: %q", staticLibPackage, overlayList)
+	}
+
+	// Check AAPT2 link flags for resource_libs dependency.
+	resourceLibFlag := "-I " + buildDir + "/.intermediates/baz/android_common/package-res.apk"
+	if !strings.Contains(aapt2Flags, resourceLibFlag) {
+		t.Errorf("Resource lib flag %q missing in aapt2 link flags: %q", resourceLibFlag, aapt2Flags)
+	}
+
+	// Check cert signing flag.
+	signedApk := m.Output("signed/foo.apk")
+	lineageFlag := signedApk.Args["flags"]
+	expectedLineageFlag := "--lineage lineage.bin"
+	if expectedLineageFlag != lineageFlag {
+		t.Errorf("Incorrect signing lineage flags, expected: %q, got: %q", expectedLineageFlag, lineageFlag)
+	}
+	signingFlag := signedApk.Args["certificates"]
+	expected := "build/make/target/product/security/platform.x509.pem build/make/target/product/security/platform.pk8"
+	if expected != signingFlag {
+		t.Errorf("Incorrect signing flags, expected: %q, got: %q", expected, signingFlag)
+	}
+	androidMkEntries := android.AndroidMkEntriesForTest(t, config, "", m.Module())[0]
+	path := androidMkEntries.EntryMap["LOCAL_CERTIFICATE"]
+	expectedPath := []string{"build/make/target/product/security/platform.x509.pem"}
+	if !reflect.DeepEqual(path, expectedPath) {
+		t.Errorf("Unexpected LOCAL_CERTIFICATE value: %v, expected: %v", path, expectedPath)
+	}
+
+	// Check device location.
+	path = androidMkEntries.EntryMap["LOCAL_MODULE_PATH"]
+	expectedPath = []string{"/tmp/target/product/test_device/product/overlay"}
+	if !reflect.DeepEqual(path, expectedPath) {
+		t.Errorf("Unexpected LOCAL_MODULE_PATH value: %v, expected: %v", path, expectedPath)
+	}
+
+	// A themed module has a different device location
+	m = ctx.ModuleForTests("foo_themed", "android_common")
+	androidMkEntries = android.AndroidMkEntriesForTest(t, config, "", m.Module())[0]
+	path = androidMkEntries.EntryMap["LOCAL_MODULE_PATH"]
+	expectedPath = []string{"/tmp/target/product/test_device/product/overlay/faza"}
+	if !reflect.DeepEqual(path, expectedPath) {
+		t.Errorf("Unexpected LOCAL_MODULE_PATH value: %v, expected: %v", path, expectedPath)
+	}
+
+	overrides := androidMkEntries.EntryMap["LOCAL_OVERRIDES_PACKAGES"]
+	expectedOverrides := []string{"foo"}
+	if !reflect.DeepEqual(overrides, expectedOverrides) {
+		t.Errorf("Unexpected LOCAL_OVERRIDES_PACKAGES value: %v, expected: %v", overrides, expectedOverrides)
+	}
+}
+
+func TestRuntimeResourceOverlay_JavaDefaults(t *testing.T) {
+	ctx, config := testJava(t, `
+		java_defaults {
+			name: "rro_defaults",
+			theme: "default_theme",
+			product_specific: true,
+			aaptflags: ["--keep-raw-values"],
+		}
+
+		runtime_resource_overlay {
+			name: "foo_with_defaults",
+			defaults: ["rro_defaults"],
+		}
+
+		runtime_resource_overlay {
+			name: "foo_barebones",
+		}
+		`)
+
+	//
+	// RRO module with defaults
+	//
+	m := ctx.ModuleForTests("foo_with_defaults", "android_common")
+
+	// Check AAPT2 link flags.
+	aapt2Flags := strings.Split(m.Output("package-res.apk").Args["flags"], " ")
+	expectedFlags := []string{"--keep-raw-values", "--no-resource-deduping", "--no-resource-removal"}
+	absentFlags := android.RemoveListFromList(expectedFlags, aapt2Flags)
+	if len(absentFlags) > 0 {
+		t.Errorf("expected values, %q are missing in aapt2 link flags, %q", absentFlags, aapt2Flags)
+	}
+
+	// Check device location.
+	path := android.AndroidMkEntriesForTest(t, config, "", m.Module())[0].EntryMap["LOCAL_MODULE_PATH"]
+	expectedPath := []string{"/tmp/target/product/test_device/product/overlay/default_theme"}
+	if !reflect.DeepEqual(path, expectedPath) {
+		t.Errorf("Unexpected LOCAL_MODULE_PATH value: %q, expected: %q", path, expectedPath)
+	}
+
+	//
+	// RRO module without defaults
+	//
+	m = ctx.ModuleForTests("foo_barebones", "android_common")
+
+	// Check AAPT2 link flags.
+	aapt2Flags = strings.Split(m.Output("package-res.apk").Args["flags"], " ")
+	unexpectedFlags := "--keep-raw-values"
+	if inList(unexpectedFlags, aapt2Flags) {
+		t.Errorf("unexpected value, %q is present in aapt2 link flags, %q", unexpectedFlags, aapt2Flags)
+	}
+
+	// Check device location.
+	path = android.AndroidMkEntriesForTest(t, config, "", m.Module())[0].EntryMap["LOCAL_MODULE_PATH"]
+	expectedPath = []string{"/tmp/target/product/test_device/system/overlay"}
+	if !reflect.DeepEqual(path, expectedPath) {
+		t.Errorf("Unexpected LOCAL_MODULE_PATH value: %v, expected: %v", path, expectedPath)
+	}
+}
+
+func TestOverrideRuntimeResourceOverlay(t *testing.T) {
+	ctx, _ := testJava(t, `
+		runtime_resource_overlay {
+			name: "foo_overlay",
+			certificate: "platform",
+			product_specific: true,
+			sdk_version: "current",
+		}
+
+		override_runtime_resource_overlay {
+			name: "bar_overlay",
+			base: "foo_overlay",
+			package_name: "com.android.bar.overlay",
+			target_package_name: "com.android.bar",
+		}
+		`)
+
+	expectedVariants := []struct {
+		moduleName        string
+		variantName       string
+		apkPath           string
+		overrides         []string
+		targetVariant     string
+		packageFlag       string
+		targetPackageFlag string
+	}{
+		{
+			variantName:       "android_common",
+			apkPath:           "/target/product/test_device/product/overlay/foo_overlay.apk",
+			overrides:         nil,
+			targetVariant:     "android_common",
+			packageFlag:       "",
+			targetPackageFlag: "",
+		},
+		{
+			variantName:       "android_common_bar_overlay",
+			apkPath:           "/target/product/test_device/product/overlay/bar_overlay.apk",
+			overrides:         []string{"foo_overlay"},
+			targetVariant:     "android_common_bar",
+			packageFlag:       "com.android.bar.overlay",
+			targetPackageFlag: "com.android.bar",
+		},
+	}
+	for _, expected := range expectedVariants {
+		variant := ctx.ModuleForTests("foo_overlay", expected.variantName)
+
+		// Check the final apk name
+		outputs := variant.AllOutputs()
+		expectedApkPath := buildDir + expected.apkPath
+		found := false
+		for _, o := range outputs {
+			if o == expectedApkPath {
+				found = true
+				break
+			}
+		}
+		if !found {
+			t.Errorf("Can't find %q in output files.\nAll outputs:%v", expectedApkPath, outputs)
+		}
+
+		// Check if the overrides field values are correctly aggregated.
+		mod := variant.Module().(*RuntimeResourceOverlay)
+		if !reflect.DeepEqual(expected.overrides, mod.properties.Overrides) {
+			t.Errorf("Incorrect overrides property value, expected: %q, got: %q",
+				expected.overrides, mod.properties.Overrides)
+		}
+
+		// Check aapt2 flags.
+		res := variant.Output("package-res.apk")
+		aapt2Flags := res.Args["flags"]
+		checkAapt2LinkFlag(t, aapt2Flags, "rename-manifest-package", expected.packageFlag)
+		checkAapt2LinkFlag(t, aapt2Flags, "rename-resources-package", "")
+		checkAapt2LinkFlag(t, aapt2Flags, "rename-overlay-target-package", expected.targetPackageFlag)
+	}
+}
+
+func TestEnforceRRO_propagatesToDependencies(t *testing.T) {
+	testCases := []struct {
+		name                    string
+		enforceRROTargets       []string
+		enforceRROExemptTargets []string
+		rroDirs                 map[string][]string
+	}{
+		{
+			name:                    "no RRO",
+			enforceRROTargets:       nil,
+			enforceRROExemptTargets: nil,
+			rroDirs: map[string][]string{
+				"foo": nil,
+				"bar": nil,
+			},
+		},
+		{
+			name:                    "enforce RRO on all",
+			enforceRROTargets:       []string{"*"},
+			enforceRROExemptTargets: nil,
+			rroDirs: map[string][]string{
+				"foo": {"product/vendor/blah/overlay/lib2/res"},
+				"bar": {"product/vendor/blah/overlay/lib2/res"},
+			},
+		},
+		{
+			name:                    "enforce RRO on foo",
+			enforceRROTargets:       []string{"foo"},
+			enforceRROExemptTargets: nil,
+			rroDirs: map[string][]string{
+				"foo": {"product/vendor/blah/overlay/lib2/res"},
+				"bar": {"product/vendor/blah/overlay/lib2/res"},
+			},
+		},
+		{
+			name:                    "enforce RRO on foo, bar exempted",
+			enforceRROTargets:       []string{"foo"},
+			enforceRROExemptTargets: []string{"bar"},
+			rroDirs: map[string][]string{
+				"foo": {"product/vendor/blah/overlay/lib2/res"},
+				"bar": nil,
+			},
+		},
+	}
+
+	productResourceOverlays := []string{
+		"product/vendor/blah/overlay",
+	}
+
+	fs := map[string][]byte{
+		"lib2/res/values/strings.xml":                             nil,
+		"product/vendor/blah/overlay/lib2/res/values/strings.xml": nil,
+	}
+
+	bp := `
+			android_app {
+				name: "foo",
+				sdk_version: "current",
+				resource_dirs: [],
+				static_libs: ["lib"],
+			}
+
+			android_app {
+				name: "bar",
+				sdk_version: "current",
+				resource_dirs: [],
+				static_libs: ["lib"],
+			}
+
+			android_library {
+				name: "lib",
+				sdk_version: "current",
+				resource_dirs: [],
+				static_libs: ["lib2"],
+			}
+
+			android_library {
+				name: "lib2",
+				sdk_version: "current",
+				resource_dirs: ["lib2/res"],
+			}
+		`
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			config := testAppConfig(nil, bp, fs)
+			config.TestProductVariables.ProductResourceOverlays = productResourceOverlays
+			if testCase.enforceRROTargets != nil {
+				config.TestProductVariables.EnforceRROTargets = testCase.enforceRROTargets
+			}
+			if testCase.enforceRROExemptTargets != nil {
+				config.TestProductVariables.EnforceRROExemptedTargets = testCase.enforceRROExemptTargets
+			}
+
+			ctx := testContext(config)
+			run(t, ctx, config)
+
+			modules := []string{"foo", "bar"}
+			for _, moduleName := range modules {
+				module := ctx.ModuleForTests(moduleName, "android_common")
+				mkEntries := android.AndroidMkEntriesForTest(t, config, "", module.Module())[0]
+				actualRRODirs := mkEntries.EntryMap["LOCAL_SOONG_PRODUCT_RRO_DIRS"]
+				if !reflect.DeepEqual(actualRRODirs, testCase.rroDirs[moduleName]) {
+					t.Errorf("exected %s LOCAL_SOONG_PRODUCT_RRO_DIRS entry: %v\ngot:%q",
+						moduleName, testCase.rroDirs[moduleName], actualRRODirs)
+				}
+			}
+		})
+	}
+}