Introduce FakePermissionEnforcer

/*

 * 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 android.os.test;

import static android.permission.PermissionManager.PERMISSION_GRANTED;

import static android.permission.PermissionManager.PERMISSION_HARD_DENIED;

import android.annotation.NonNull;

import android.content.AttributionSource;

import android.os.PermissionEnforcer;

import java.util.HashSet;

import java.util.Set;

/**

 * Fake for {@link PermissionEnforcer}. Useful for tests wanting to mock the

 * permission checks of an AIDL service. FakePermissionEnforcer may be passed

 * to the constructor of the AIDL-generated Stub class.

 *

 */

public class FakePermissionEnforcer extends PermissionEnforcer {

    private Set<String> mGranted;

    public FakePermissionEnforcer() {

        mGranted = new HashSet();

    }

    public void grant(String permission) {

        mGranted.add(permission);

    }

    public void revoke(String permission) {

        mGranted.remove(permission);

    }

    private boolean granted(String permission) {

        return mGranted.contains(permission);

    }

    @Override

    protected int checkPermission(@NonNull String permission,

              @NonNull AttributionSource source) {

        return granted(permission) ? PERMISSION_GRANTED : PERMISSION_HARD_DENIED;

    }

    @Override

    protected int checkPermission(@NonNull String permission, int pid, int uid) {

        return granted(permission) ? PERMISSION_GRANTED : PERMISSION_HARD_DENIED;

    }

}

per-file FakePermissionEnforcer.java = file:/tests/EnforcePermission/OWNERS