/**
* The MIT License
* Copyright (c) 2014-2016 Ilkka Seppälä
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package com.iluwatar.command;
import static org.junit.Assert.assertEquals;
import org.junit.Test;
/**
* The Command pattern is a behavioral design pattern in which an object is used to encapsulate all
* information needed to perform an action or trigger an event at a later time. This information
* includes the method name, the object that owns the method and values for the method parameters.
*
* <p>Four terms always associated with the command pattern are command, receiver, invoker and
* client. A command object (spell) knows about the receiver (target) and invokes a method of
* the receiver.Values for parameters of the receiver method are stored in the command. The receiver
* then does the work. An invoker object (wizard) knows how to execute a command, and optionally
* does bookkeeping about the command execution. The invoker does not know anything about a
* concrete command, it knows only about command interface. Both an invoker object and several
* command objects are held by a client object (app). The client decides which commands to execute
* at which points. To execute a command, it passes the command object to the invoker object.
*/
public class CommandTest {
private static final String GOBLIN = "Goblin";
/**
* This test verifies that when the wizard casts spells on the goblin. The wizard keeps track of
* the previous spells cast, so it is easy to undo them. In addition, it also verifies that the
* wizard keeps track of the spells undone, so they can be redone.
*/
@Test
public void testCommand() {
Wizard wizard = new Wizard();
Goblin goblin = new Goblin();
wizard.castSpell(new ShrinkSpell(), goblin);
verifyGoblin(goblin, GOBLIN, Size.SMALL, Visibility.VISIBLE);
wizard.castSpell(new InvisibilitySpell(), goblin);
verifyGoblin(goblin, GOBLIN, Size.SMALL, Visibility.INVISIBLE);
wizard.undoLastSpell();
verifyGoblin(goblin, GOBLIN, Size.SMALL, Visibility.VISIBLE);
wizard.undoLastSpell();
verifyGoblin(goblin, GOBLIN, Size.NORMAL, Visibility.VISIBLE);
wizard.redoLastSpell();
verifyGoblin(goblin, GOBLIN, Size.SMALL, Visibility.VISIBLE);
wizard.redoLastSpell();
verifyGoblin(goblin, GOBLIN, Size.SMALL, Visibility.INVISIBLE);
}
/**
* This method asserts that the passed goblin object has the name as expectedName, size as
* expectedSize and visibility as expectedVisibility.
*
* @param goblin a goblin object whose state is to be verified against other parameters
* @param expectedName expectedName of the goblin
* @param expectedSize expected size of the goblin
* @param expectedVisibilty exepcted visibility of the goblin
*/
private void verifyGoblin(Goblin goblin, String expectedName, Size expectedSize,
Visibility expectedVisibilty) {
assertEquals("Goblin's name must be same as expectedName", expectedName, goblin.toString());
assertEquals("Goblin's size must be same as expectedSize", expectedSize, goblin.getSize());
assertEquals("Goblin's visibility must be same as expectedVisibility", expectedVisibilty,
goblin.getVisibility());
}
}