Add Tests for Session and infinite recursion

/*

 * Copyright (C) 2019 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.telecom.tests;

import static junit.framework.Assert.fail;

import android.telecom.Logging.Session;

import android.test.suitebuilder.annotation.SmallTest;

import org.junit.Test;

import org.junit.runner.RunWith;

import org.junit.runners.JUnit4;

/**

 * Unit tests for android.telecom.Logging.Session

 */

@RunWith(JUnit4.class)

public class SessionTest {

    /**

     * Ensure creating two sessions that are parent/child of each other does not lead to a crash

     * or infinite recursion.

     */

    @SmallTest

    @Test

    public void testRecursion() {

        Session parentSession =  createTestSession("parent", "p");

        Session childSession =  createTestSession("child", "c");

        parentSession.addChild(childSession);

        parentSession.setParentSession(childSession);

        childSession.addChild(parentSession);

        childSession.setParentSession(parentSession);

        // Make sure calling these methods does not result in a crash

        try {

            parentSession.printFullSessionTree();

            childSession.printFullSessionTree();

            parentSession.getFullMethodPath(false);

            childSession.getFullMethodPath(false);

            parentSession.toString();

            childSession.toString();

            Session.Info.getInfo(parentSession);

            Session.Info.getInfo(childSession);

        } catch (Exception e) {

            fail();

        }

    }

    private Session createTestSession(String name, String methodName) {

        return new Session(name, methodName, 0, false, null);

    }

}