Add unit tests for AppIdPermissionPolicy

Bug: 280853174
Test: AppIdPermissionPolicyTest

Change-Id: I67c3c86b2ca4c0a87b05922f3a7fcc3bff04123d
diff --git a/services/permission/Android.bp b/services/permission/Android.bp
index dc9b558..59ca851 100644
--- a/services/permission/Android.bp
+++ b/services/permission/Android.bp
@@ -17,8 +17,8 @@
     visibility: ["//frameworks/base/services"],
 }
 
-java_library_static {
-    name: "services.permission",
+java_library {
+    name: "services.permission-pre-jarjar",
     defaults: ["platform_service_defaults"],
     srcs: [":services.permission-sources"],
     libs: [
@@ -32,7 +32,6 @@
         // Adds reflection-less suppressed exceptions and AutoCloseable.use().
         "kotlin-stdlib-jdk7",
     ],
-    jarjar_rules: "jarjar-rules.txt",
     kotlincflags: [
         "-Xjvm-default=all",
         "-Xno-call-assertions",
@@ -40,3 +39,9 @@
         "-Xno-receiver-assertions",
     ],
 }
+
+java_library {
+    name: "services.permission",
+    static_libs: ["services.permission-pre-jarjar"],
+    jarjar_rules: "jarjar-rules.txt",
+}
diff --git a/services/tests/PermissionServiceMockingTests/Android.bp b/services/tests/PermissionServiceMockingTests/Android.bp
new file mode 100644
index 0000000..cedfd2c
--- /dev/null
+++ b/services/tests/PermissionServiceMockingTests/Android.bp
@@ -0,0 +1,44 @@
+// Copyright (C) 2023 The Android Open Source Project
+//
+// 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 {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "frameworks_base_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["frameworks_base_license"],
+}
+
+android_test {
+    name: "PermissionServiceMockingTests",
+    defaults: [
+        // This is needed for the ExtendedMockitoRule
+        "modules-utils-testable-device-config-defaults",
+    ],
+    srcs: [
+        "src/**/*.kt",
+    ],
+    static_libs: [
+        "mockingservicestests-utils-mockito",
+        "services.core",
+        "services.permission-pre-jarjar",
+        "servicestests-core-utils",
+        "servicestests-utils",
+    ],
+    platform_apis: true,
+    test_suites: [
+        "device-tests",
+    ],
+}
diff --git a/services/tests/PermissionServiceMockingTests/AndroidManifest.xml b/services/tests/PermissionServiceMockingTests/AndroidManifest.xml
new file mode 100644
index 0000000..32b64ac
--- /dev/null
+++ b/services/tests/PermissionServiceMockingTests/AndroidManifest.xml
@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+     Copyright (C) 2023 The Android Open Source Project
+
+     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.
+-->
+
+<manifest
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.android.server.permission.test">
+
+    <application android:debuggable="true">
+        <uses-library android:name="android.test.mock" android:required="true" />
+        <uses-library android:name="android.test.runner" />
+    </application>
+
+    <instrumentation
+        android:name="androidx.test.runner.AndroidJUnitRunner"
+        android:targetPackage="com.android.server.permission.test"
+        android:label="Permission Service Mocking Tests" />
+</manifest>
diff --git a/services/tests/PermissionServiceMockingTests/AndroidTest.xml b/services/tests/PermissionServiceMockingTests/AndroidTest.xml
new file mode 100644
index 0000000..157c4f0
--- /dev/null
+++ b/services/tests/PermissionServiceMockingTests/AndroidTest.xml
@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!-- Copyright (C) 2023 The Android Open Source Project
+
+     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.
+-->
+<configuration description="Configuration for PermissionServiceMockingTests">
+    <option name="test-tag" value="PermissionServiceMockingTests" />
+
+    <target_preparer class="com.android.tradefed.targetprep.suite.SuiteApkInstaller">
+        <option name="cleanup-apks" value="true" />
+        <option name="test-file-name" value="PermissionServiceMockingTests.apk" />
+    </target_preparer>
+
+    <test class="com.android.tradefed.testtype.AndroidJUnitTest" >
+        <option name="package" value="com.android.server.permission.test" />
+        <option name="runner" value="androidx.test.runner.AndroidJUnitRunner" />
+    </test>
+</configuration>
diff --git a/services/tests/PermissionServiceMockingTests/OWNERS b/services/tests/PermissionServiceMockingTests/OWNERS
new file mode 100644
index 0000000..dafdf0f
--- /dev/null
+++ b/services/tests/PermissionServiceMockingTests/OWNERS
@@ -0,0 +1 @@
+include platform/frameworks/base:/core/java/android/permission/OWNERS
diff --git a/services/tests/PermissionServiceMockingTests/src/com/android/server/permission/test/AppIdPermissionPolicyTest.kt b/services/tests/PermissionServiceMockingTests/src/com/android/server/permission/test/AppIdPermissionPolicyTest.kt
new file mode 100644
index 0000000..3ef3a89
--- /dev/null
+++ b/services/tests/PermissionServiceMockingTests/src/com/android/server/permission/test/AppIdPermissionPolicyTest.kt
@@ -0,0 +1,536 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * 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 com.android.server.permission.test
+
+import android.content.pm.PackageManager
+import android.content.pm.PermissionGroupInfo
+import android.content.pm.PermissionInfo
+import android.os.Bundle
+import android.util.ArrayMap
+import android.util.ArraySet
+import android.util.SparseArray
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.android.modules.utils.testing.ExtendedMockitoRule
+import com.android.server.extendedtestutils.wheneverStatic
+import com.android.server.permission.access.MutableAccessState
+import com.android.server.permission.access.MutableUserState
+import com.android.server.permission.access.MutateStateScope
+import com.android.server.permission.access.immutable.* // ktlint-disable no-wildcard-imports
+import com.android.server.permission.access.permission.AppIdPermissionPolicy
+import com.android.server.permission.access.permission.Permission
+import com.android.server.permission.access.permission.PermissionFlags
+import com.android.server.pm.parsing.PackageInfoUtils
+import com.android.server.pm.pkg.AndroidPackage
+import com.android.server.pm.pkg.PackageState
+import com.android.server.pm.pkg.PackageUserState
+import com.android.server.pm.pkg.component.ParsedPermission
+import com.android.server.pm.pkg.component.ParsedPermissionGroup
+import com.android.server.testutils.mock
+import com.android.server.testutils.whenever
+import com.google.common.truth.Truth.assertWithMessage
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+
+/**
+ * Mocking unit test for AppIdPermissionPolicy.
+ */
+@RunWith(AndroidJUnit4::class)
+class AppIdPermissionPolicyTest {
+    private lateinit var oldState: MutableAccessState
+    private lateinit var newState: MutableAccessState
+
+    private lateinit var androidPackage0: AndroidPackage
+    private lateinit var androidPackage1: AndroidPackage
+
+    private lateinit var packageState0: PackageState
+    private lateinit var packageState1: PackageState
+
+    private val appIdPermissionPolicy = AppIdPermissionPolicy()
+
+    @Rule
+    @JvmField
+    val extendedMockitoRule = ExtendedMockitoRule.Builder(this)
+        .spyStatic(PackageInfoUtils::class.java)
+        .build()
+
+    @Before
+    fun init() {
+        oldState = MutableAccessState()
+        createUserState(USER_ID_0)
+        createUserState(USER_ID_1)
+        oldState.mutateExternalState().setPackageStates(ArrayMap())
+
+        androidPackage0 = mockAndroidPackage(
+            PACKAGE_NAME_0,
+            PERMISSION_GROUP_NAME_0,
+            PERMISSION_NAME_0
+        )
+        androidPackage1 = mockAndroidPackage(
+            PACKAGE_NAME_1,
+            PERMISSION_GROUP_NAME_1,
+            PERMISSION_NAME_1
+        )
+
+        packageState0 = mockPackageState(APP_ID_0, androidPackage0)
+        packageState1 = mockPackageState(APP_ID_1, androidPackage1)
+    }
+
+    private fun mockAndroidPackage(
+        packageName: String,
+        permissionGroupName: String,
+        permissionName: String,
+    ): AndroidPackage {
+        val parsedPermissionGroup = mock<ParsedPermissionGroup> {
+            whenever(name).thenReturn(permissionGroupName)
+            whenever(metaData).thenReturn(Bundle())
+        }
+
+        @Suppress("DEPRECATION")
+        val permissionGroupInfo = PermissionGroupInfo().apply {
+            name = permissionGroupName
+            this.packageName = packageName
+        }
+        wheneverStatic {
+            PackageInfoUtils.generatePermissionGroupInfo(
+                parsedPermissionGroup,
+                PackageManager.GET_META_DATA.toLong()
+            )
+        }.thenReturn(permissionGroupInfo)
+
+        val parsedPermission = mock<ParsedPermission> {
+            whenever(name).thenReturn(permissionName)
+            whenever(isTree).thenReturn(false)
+            whenever(metaData).thenReturn(Bundle())
+        }
+
+        @Suppress("DEPRECATION")
+        val permissionInfo = PermissionInfo().apply {
+            name = permissionName
+            this.packageName = packageName
+        }
+        wheneverStatic {
+            PackageInfoUtils.generatePermissionInfo(
+                parsedPermission,
+                PackageManager.GET_META_DATA.toLong()
+            )
+        }.thenReturn(permissionInfo)
+
+        val requestedPermissions = ArraySet<String>()
+        return mock {
+            whenever(this.packageName).thenReturn(packageName)
+            whenever(this.requestedPermissions).thenReturn(requestedPermissions)
+            whenever(permissionGroups).thenReturn(listOf(parsedPermissionGroup))
+            whenever(permissions).thenReturn(listOf(parsedPermission))
+            whenever(signingDetails).thenReturn(mock {})
+        }
+    }
+
+    private fun mockPackageState(
+        appId: Int,
+        androidPackage: AndroidPackage,
+    ): PackageState {
+        val packageName = androidPackage.packageName
+        oldState.mutateExternalState().mutateAppIdPackageNames().mutateOrPut(appId) {
+            MutableIndexedListSet()
+        }.add(packageName)
+
+        val userStates = SparseArray<PackageUserState>().apply {
+            put(USER_ID_0, mock { whenever(isInstantApp).thenReturn(false) })
+        }
+        val mockPackageState: PackageState = mock {
+            whenever(this.packageName).thenReturn(packageName)
+            whenever(this.appId).thenReturn(appId)
+            whenever(this.androidPackage).thenReturn(androidPackage)
+            whenever(isSystem).thenReturn(false)
+            whenever(this.userStates).thenReturn(userStates)
+        }
+        oldState.mutateExternalState().setPackageStates(
+            oldState.mutateExternalState().packageStates.toMutableMap().apply {
+                put(packageName, mockPackageState)
+            }
+        )
+        return mockPackageState
+    }
+
+    private fun createUserState(userId: Int) {
+        oldState.mutateUserStatesNoWrite().put(userId, MutableUserState())
+    }
+
+    @Test
+    fun testResetRuntimePermissions_runtimeGranted_getsRevoked() {
+        val oldFlags = PermissionFlags.RUNTIME_GRANTED
+        val expectedNewFlags = 0
+        testResetRuntimePermissions(oldFlags, expectedNewFlags) {}
+    }
+
+    @Test
+    fun testResetRuntimePermissions_roleGranted_getsGranted() {
+        val oldFlags = PermissionFlags.ROLE
+        val expectedNewFlags = PermissionFlags.ROLE or PermissionFlags.RUNTIME_GRANTED
+        testResetRuntimePermissions(oldFlags, expectedNewFlags) {}
+    }
+
+    @Test
+    fun testResetRuntimePermissions_nullAndroidPackage_remainsUnchanged() {
+        val oldFlags = PermissionFlags.RUNTIME_GRANTED
+        val expectedNewFlags = PermissionFlags.RUNTIME_GRANTED
+        testResetRuntimePermissions(oldFlags, expectedNewFlags) {
+            whenever(packageState0.androidPackage).thenReturn(null)
+        }
+    }
+
+    private inline fun testResetRuntimePermissions(
+        oldFlags: Int,
+        expectedNewFlags: Int,
+        additionalSetup: () -> Unit
+    ) {
+        createSystemStatePermission(
+            APP_ID_0,
+            PACKAGE_NAME_0,
+            PERMISSION_NAME_0,
+            PermissionInfo.PROTECTION_DANGEROUS
+        )
+        androidPackage0.requestedPermissions.add(PERMISSION_NAME_0)
+        oldState.mutateUserState(USER_ID_0)!!.mutateAppIdPermissionFlags().mutateOrPut(APP_ID_0) {
+            MutableIndexedMap()
+        }.put(PERMISSION_NAME_0, oldFlags)
+
+        additionalSetup()
+
+        mutateState {
+            with(appIdPermissionPolicy) {
+                resetRuntimePermissions(PACKAGE_NAME_0, USER_ID_0)
+            }
+        }
+
+        val actualFlags = getPermissionFlags(APP_ID_0, USER_ID_0, PERMISSION_NAME_0)
+        assertWithMessage(
+            "After resetting runtime permissions, permission flags did not match" +
+            " expected values: expectedNewFlags is $expectedNewFlags," +
+            " actualFlags is $actualFlags, while the oldFlags is $oldFlags"
+        )
+            .that(actualFlags)
+            .isEqualTo(expectedNewFlags)
+    }
+
+    @Test
+    fun testOnPackageAdded_permissionsOfMissingSystemApp_getsAdopted() {
+        testOnPackageAdded {
+            adoptPermissionTestSetup()
+            whenever(packageState1.androidPackage).thenReturn(null)
+        }
+
+        val permission0 = newState.systemState.permissions[PERMISSION_NAME_0]
+        assertWithMessage(
+            "After onPackageAdded() is called for a null adopt permission package," +
+            " the permission package name: ${permission0!!.packageName} did not match" +
+            " the expected package name: $PACKAGE_NAME_0"
+        )
+            .that(permission0.packageName)
+            .isEqualTo(PACKAGE_NAME_0)
+    }
+
+    @Test
+    fun testOnPackageAdded_permissionsOfExistingSystemApp_notAdopted() {
+        testOnPackageAdded {
+            adoptPermissionTestSetup()
+        }
+
+        val permission0 = newState.systemState.permissions[PERMISSION_NAME_0]
+        assertWithMessage(
+            "After onPackageAdded() is called for a non-null adopt permission" +
+            " package, the permission package name: ${permission0!!.packageName} should" +
+            " not match the package name: $PACKAGE_NAME_0"
+        )
+            .that(permission0.packageName)
+            .isNotEqualTo(PACKAGE_NAME_0)
+    }
+
+    @Test
+    fun testOnPackageAdded_permissionsOfNonSystemApp_notAdopted() {
+        testOnPackageAdded {
+            adoptPermissionTestSetup()
+            whenever(packageState1.isSystem).thenReturn(false)
+        }
+
+        val permission0 = newState.systemState.permissions[PERMISSION_NAME_0]
+        assertWithMessage(
+            "After onPackageAdded() is called for a non-system adopt permission" +
+                " package, the permission package name: ${permission0!!.packageName} should" +
+                " not match the package name: $PACKAGE_NAME_0"
+        )
+            .that(permission0.packageName)
+            .isNotEqualTo(PACKAGE_NAME_0)
+    }
+
+    private fun adoptPermissionTestSetup() {
+        createSystemStatePermission(
+            APP_ID_1,
+            PACKAGE_NAME_1,
+            PERMISSION_NAME_0,
+            PermissionInfo.PROTECTION_SIGNATURE
+        )
+        whenever(androidPackage0.adoptPermissions).thenReturn(listOf(PACKAGE_NAME_1))
+        whenever(packageState1.isSystem).thenReturn(true)
+    }
+
+    @Test
+    fun testOnPackageAdded_newPermissionGroup_getsDeclared() {
+        testOnPackageAdded {}
+
+        assertWithMessage(
+            "After onPackageAdded() is called when there is no existing" +
+            " permission groups, the new permission group $PERMISSION_GROUP_NAME_0 is not added"
+        )
+            .that(newState.systemState.permissionGroups[PERMISSION_GROUP_NAME_0]?.name)
+            .isEqualTo(PERMISSION_GROUP_NAME_0)
+    }
+
+    @Test
+    fun testOnPackageAdded_systemAppTakingOverPermissionGroupDefinition_getsTakenOver() {
+        testOnPackageAdded {
+            whenever(packageState0.isSystem).thenReturn(true)
+            createSystemStatePermissionGroup(PACKAGE_NAME_1, PERMISSION_GROUP_NAME_0)
+        }
+
+        assertWithMessage(
+            "After onPackageAdded() is called when $PERMISSION_GROUP_NAME_0 already" +
+            " exists in the system, the system app $PACKAGE_NAME_0 didn't takeover the ownership" +
+            " of this permission group"
+        )
+            .that(newState.systemState.permissionGroups[PERMISSION_GROUP_NAME_0]?.packageName)
+            .isEqualTo(PACKAGE_NAME_0)
+    }
+
+    @Test
+    fun testOnPackageAdded_instantApps_remainsUnchanged() {
+        testOnPackageAdded {
+            (packageState0.userStates as SparseArray<PackageUserState>).apply {
+                put(0, mock { whenever(isInstantApp).thenReturn(true) })
+            }
+        }
+
+        assertWithMessage(
+            "After onPackageAdded() is called for an instant app," +
+            " the new permission group $PERMISSION_GROUP_NAME_0 should not be added"
+        )
+            .that(newState.systemState.permissionGroups[PERMISSION_GROUP_NAME_0])
+            .isNull()
+    }
+
+    @Test
+    fun testOnPackageAdded_nonSystemAppTakingOverPermissionGroupDefinition_remainsUnchanged() {
+        testOnPackageAdded {
+            createSystemStatePermissionGroup(PACKAGE_NAME_1, PERMISSION_GROUP_NAME_0)
+        }
+
+        assertWithMessage(
+            "After onPackageAdded() is called when $PERMISSION_GROUP_NAME_0 already" +
+            " exists in the system, non-system app $PACKAGE_NAME_0 shouldn't takeover ownership" +
+            " of this permission group"
+        )
+            .that(newState.systemState.permissionGroups[PERMISSION_GROUP_NAME_0]?.packageName)
+            .isEqualTo(PACKAGE_NAME_1)
+    }
+
+    @Test
+    fun testOnPackageAdded_takingOverPermissionGroupDeclaredBySystemApp_remainsUnchanged() {
+        testOnPackageAdded {
+            whenever(packageState1.isSystem).thenReturn(true)
+            createSystemStatePermissionGroup(PACKAGE_NAME_1, PERMISSION_GROUP_NAME_0)
+        }
+
+        assertWithMessage(
+            "After onPackageAdded() is called when $PERMISSION_GROUP_NAME_0 already" +
+            " exists in the system and is owned by a system app, app $PACKAGE_NAME_0 shouldn't" +
+            " takeover ownership of this permission group"
+        )
+            .that(newState.systemState.permissionGroups[PERMISSION_GROUP_NAME_0]?.packageName)
+            .isEqualTo(PACKAGE_NAME_1)
+    }
+
+    @Test
+    fun testOnPackageAdded_newPermission_getsDeclared() {
+        testOnPackageAdded {}
+
+        assertWithMessage(
+            "After onPackageAdded() is called when there is no existing" +
+            " permissions, the new permission $PERMISSION_NAME_0 is not added"
+        )
+            .that(newState.systemState.permissions[PERMISSION_NAME_0]?.name)
+            .isEqualTo(PERMISSION_NAME_0)
+    }
+
+    @Test
+    fun testOnPackageAdded_configPermission_getsTakenOver() {
+        testOnPackageAdded {
+            whenever(packageState0.isSystem).thenReturn(true)
+            createSystemStatePermission(
+                APP_ID_0,
+                PACKAGE_NAME_1,
+                PERMISSION_NAME_0,
+                PermissionInfo.PROTECTION_DANGEROUS,
+                Permission.TYPE_CONFIG,
+                false
+            )
+        }
+
+        assertWithMessage(
+            "After onPackageAdded() is called for a config permission with" +
+            " no owner, the ownership is not taken over by a system app $PACKAGE_NAME_0"
+        )
+            .that(newState.systemState.permissions[PERMISSION_NAME_0]?.packageName)
+            .isEqualTo(PACKAGE_NAME_0)
+    }
+
+    @Test
+    fun testOnPackageAdded_systemAppTakingOverPermissionDefinition_getsTakenOver() {
+        testOnPackageAdded {
+            whenever(packageState0.isSystem).thenReturn(true)
+            createSystemStatePermission(
+                APP_ID_1,
+                PACKAGE_NAME_1,
+                PERMISSION_NAME_0,
+                PermissionInfo.PROTECTION_DANGEROUS
+            )
+        }
+
+        assertWithMessage(
+            "After onPackageAdded() is called when $PERMISSION_NAME_0 already" +
+            " exists in the system, the system app $PACKAGE_NAME_0 didn't takeover the ownership" +
+            " of this permission"
+        )
+            .that(newState.systemState.permissions[PERMISSION_NAME_0]?.packageName)
+            .isEqualTo(PACKAGE_NAME_0)
+    }
+
+    @Test
+    fun testOnPackageAdded_nonSystemAppTakingOverPermissionDefinition_remainsUnchanged() {
+        testOnPackageAdded {
+            createSystemStatePermission(
+                APP_ID_1,
+                PACKAGE_NAME_1,
+                PERMISSION_NAME_0,
+                PermissionInfo.PROTECTION_DANGEROUS
+            )
+        }
+
+        assertWithMessage(
+            "After onPackageAdded() is called when $PERMISSION_NAME_0 already" +
+            " exists in the system, the non-system app $PACKAGE_NAME_0 shouldn't takeover" +
+            " ownership of this permission"
+        )
+            .that(newState.systemState.permissions[PERMISSION_NAME_0]?.packageName)
+            .isEqualTo(PACKAGE_NAME_1)
+    }
+
+    @Test
+    fun testOnPackageAdded_takingOverPermissionDeclaredBySystemApp_remainsUnchanged() {
+        testOnPackageAdded {
+            whenever(packageState1.isSystem).thenReturn(true)
+            createSystemStatePermission(
+                APP_ID_1,
+                PACKAGE_NAME_1,
+                PERMISSION_NAME_0,
+                PermissionInfo.PROTECTION_DANGEROUS
+            )
+        }
+
+        assertWithMessage(
+            "After onPackageAdded() is called when $PERMISSION_NAME_0 already" +
+            " exists in system and is owned by a system app, the app $PACKAGE_NAME_0 shouldn't" +
+            " takeover ownership of this permission"
+        )
+            .that(newState.systemState.permissions[PERMISSION_NAME_0]?.packageName)
+            .isEqualTo(PACKAGE_NAME_1)
+    }
+
+    private inline fun testOnPackageAdded(mockBehaviorOverride: () -> Unit) {
+        mockBehaviorOverride()
+
+        mutateState {
+            with(appIdPermissionPolicy) {
+                onPackageAdded(packageState0)
+            }
+        }
+    }
+
+    private inline fun mutateState(action: MutateStateScope.() -> Unit) {
+        newState = oldState.toMutable()
+        MutateStateScope(oldState, newState).action()
+    }
+
+    private fun createSystemStatePermission(
+        appId: Int,
+        packageName: String,
+        permissionName: String,
+        protectionLevel: Int,
+        type: Int = Permission.TYPE_MANIFEST,
+        isReconciled: Boolean = true,
+        isTree: Boolean = false
+    ) {
+        @Suppress("DEPRECATION")
+        val permissionInfo = PermissionInfo().apply {
+            name = permissionName
+            this.packageName = packageName
+            this.protectionLevel = protectionLevel
+        }
+        val permission = Permission(permissionInfo, isReconciled, type, appId)
+        if (isTree) {
+            oldState.mutateSystemState().mutatePermissionTrees().put(permissionName, permission)
+        } else {
+            oldState.mutateSystemState().mutatePermissions().put(permissionName, permission)
+        }
+    }
+
+    private fun createSystemStatePermissionGroup(packageName: String, permissionGroupName: String) {
+        @Suppress("DEPRECATION")
+        val permissionGroupInfo = PermissionGroupInfo().apply {
+            name = permissionGroupName
+            this.packageName = packageName
+        }
+        oldState.mutateSystemState().mutatePermissionGroups()[permissionGroupName] =
+            permissionGroupInfo
+    }
+
+    fun getPermissionFlags(
+        appId: Int,
+        userId: Int,
+        permissionName: String,
+        state: MutableAccessState = newState
+    ): Int =
+        state.userStates[userId]?.appIdPermissionFlags?.get(appId).getWithDefault(permissionName, 0)
+
+    companion object {
+        private const val PACKAGE_NAME_0 = "packageName0"
+        private const val PACKAGE_NAME_1 = "packageName1"
+
+        private const val APP_ID_0 = 0
+        private const val APP_ID_1 = 1
+
+        private const val PERMISSION_NAME_0 = "permissionName0"
+        private const val PERMISSION_NAME_1 = "permissionName1"
+
+        private const val PERMISSION_GROUP_NAME_0 = "permissionGroupName0"
+        private const val PERMISSION_GROUP_NAME_1 = "permissionGroupName1"
+
+        private const val USER_ID_0 = 0
+        private const val USER_ID_1 = 1
+    }
+}