Add FakeSettingsProviderRule class

        }

    }

    /**

     * Creates a {@link org.junit.rules.TestRule} that makes sure {@link #clearSettingsProvider()}

     * is triggered before and after each test.

     */

    public static FakeSettingsProviderRule rule() {

        return new FakeSettingsProviderRule();

    }

    /**

     * This needs to be called before and after using the FakeSettingsProvider class.

     */

/*

 * Copyright (C) 2020 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.internal.util.test;

import android.content.Context;

import android.provider.Settings;

import android.test.mock.MockContentResolver;

import org.junit.rules.TestRule;

import org.junit.runner.Description;

import org.junit.runners.model.Statement;

/**

 * JUnit Rule helps keeping test {@link FakeSettingsProvider} clean.

 *

 * <p>It clears {@link FakeSettingsProvider} before and after each test. Example use:

 * <pre class="code"><code class="java">

 * public class ExampleTest {

 *

 *     @Rule public FakeSettingsProviderRule rule = FakeSettingsProvider.rule();

 *

 *     @Test

 *     public void shouldDoSomething() {

 *         ContextResolver cr = rule.mockContentResolver(mContext);

 *         Settings.Global.putInt(cr, "my_setting_name", 1);

 *         // Test code relying on my_setting_name value using cr

 *     }

 * }

 * </code></pre>

 *

 * @see FakeSettingsProvider

 */

public final class FakeSettingsProviderRule implements TestRule {

    /** Prevent initialization outside {@link FakeSettingsProvider}. */

    FakeSettingsProviderRule() {

    }

    /**

     * Creates a {@link MockContentResolver} that uses the {@link FakeSettingsProvider} as the

     * {@link Settings#AUTHORITY} provider.

     */

    public MockContentResolver mockContentResolver(Context context) {

        MockContentResolver contentResolver = new MockContentResolver(context);

        contentResolver.addProvider(Settings.AUTHORITY, new FakeSettingsProvider());

        return contentResolver;

    }

    @Override

    public Statement apply(Statement base, Description description) {

        return new Statement() {

            public void evaluate() throws Throwable {

                FakeSettingsProvider.clearSettingsProvider();

                try {

                    base.evaluate();

                } finally {

                    FakeSettingsProvider.clearSettingsProvider();

                }

            }

        };

    }

}