test private method mock object - ntut.edu.twjykuo/train/utmock_30.pdf ·...

國立臺北科技大學資訊工程系郭忠義

Test Private MethodMock Object

國立臺北科技大學資訊工程系

郭忠義


測試 private method 原則單元測試

測試客戶端如何使用物件，驗證物件行為是否符合預期。

Object-Oriented 封裝原則封裝變化：定義物件邊界，及外部可視介面，封裝物件內部

變化以隔離物件內外。

封裝細節：客戶端，不需了解物件內部資訊。

不須特別針對private/protected method測試 Visual studio 2012刪除2010 accessor測試private method機制。根據TDD精神，所有production code都是為通過測試案例，

所以不會有涵蓋不到的production code。

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測試 private - 充分測試 public 內聚力高原則

Private method使用 code review即可。充分測試 public method，即可充分測試到private method。若無法充分測試到 private method

over design• TDD中，private是使用refactoring的extract method產生，若測試有涵蓋不到private method的code，應刪除此code。

private method是複雜的• 意即複雜public method、複雜的 object責任• 根據Single Responsibility Principle，重構此object，設計其它

object負責此任務。

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測試 private method 客戶滿額打折，當日累積滿額。

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public class Customer {public static final int UPPER_BOUND=500;private int order[]; //訂單簡化紀錄private int getAmountOfDay() {

int money=0;for (int i=0; i=UPPER_BOUND);

}}

Customer- order: int []

- getAmountOdDay+ exceedDayLimit(int)


測試 private – getAmountOfDay()

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import static org.junit.Assert.*;import org.junit.After;import org.junit.Before;import org.junit.Test;public class CustomerTest {

private Customer c; @Beforepublic void setUp() throws Exception {

int [] order = {10, 20, 30, 40,50};c = new Customer(order);

}@Afterpublic void tearDown() throws Exception {

c=null;}@Testpublic void testExceedDayLimit() {

assertEquals(false, c.exceedDayLimit(300));assertEquals(true, c.exceedDayLimit(1000));

}}


Mock – Java Mockito 下載 mockito https://code.google.com/p/mockito/

解壓縮mockito-1.9.5.zip到C:\eclipse\mockito

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Mock – Java Mockito Mockito 程式直接呼叫static function

Foo foo = mock(Foo.class)，非寫成 Foo foo = Mockito.mock(Foo.class)

• Window - Preferences - Java - Editor - Content Assist• Add import instead of qualified name 和 Use static imports 打勾。

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Mock – Java Mockito 開啟Eclipse，造出Project - TestMock 將mockito-all-1.9.jar加到the build path

點選TestMock Project下的JRE System 按右鍵Build Path的Configure Build Path.. Properties for TestMock的Libraries的Add External JAR.. 選擇Mockito-all1.9.jar開啟

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Mock – Java Mockito 開啟Eclipse，造出Project - TestMock

造出 ITranslator interface

造出Greeting class

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public class Greeting {private ITranslator translator;public Greeting(ITranslator translator) {

this.translator = translator; }public String sayHello(String language, String name) {

return translator.translate("English", language, "Hello") + " " + name;}

}

public interface ITranslator {public abstract String translate(String fromLanguage,

String toLanguage, String word);}


Mock – Java Mockito Mock 架構

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Setup(creation)

Exercise(test)

Verify

待測程式

(Greeting.java)Mock Object

(Itranslator.java)

expectations

expectations

InvokeI/O

Greeting

sayHello()

ITranslator

translat()


Mock – Java Mockito 造出 mock/stub物件

Itranslator mockTranslator = mock(Itranslator.class);

待測物件greeting的sayHello()，呼叫mockTranslator的translate()，會產生的結果。 when(mockTranslator.translate("English", "Italian",

"Hello")).thenReturn("Ciau");

translate()執行時，丟出exception doThrow(new RunTimeException()).when(mockTranslator). translate();

translate()執行時，不作任何動作 doNothing().when(mockTranslator).translate();

驗證待測物件greeting是否呼叫所依賴物件mockTranslator 2的translate() 。 verify(mockTranslator). translate()(…) 11


Mock – Java Mockito 造出Unit Test: File-New-Junit Unit Test

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import static org.junit.Assert.*;import org.junit.After;import org.junit.Before;import org.junit.Test;import static org.mockito.Mockito.*;public class TestMock {

@Beforepublic void setUp() throws Exception { }@Afterpublic void tearDown() throws Exception { }


Mock – Java Mockito

Run As – Junit Test

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@Testpublic void shouldTestGreetingInItalian(){

//setupITranslator mockTranslator = mock(ITranslator.class);Greeting greeting = new Greeting(mockTranslator);when(mockTranslator.translate(“English”, “Italian”, “Hello”)).thenReturn(“Ciau”); //executeassertEquals("Ciau Paulo", greeting.sayHello("Italian", "Paulo"));//verifyverify(mockTranslator).translate("English", "Italian", "Hello");

}}


Command設計模式監控系統造一個TestServer Project

待測類別為 Server類別，整個系統劇本• 利用Command Design Pattern設計監控系統。• 每一個門有一個跟Server註冊的ICommand物件監控。• 若門被打開則回傳IResult物件，訊息為CRITICAL，此時Server物件啟動IAlert物件警示通知。

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Server+ monitor()+ addCommand(ICommand)+ removeCommand(Icommand)+ getCommandSize(): int IResult

+ OK = 1+ CRITICAL = 2+ getStatus(): int+ getMessage: String

ICommand+ execute(): IResult

DoorCommand+ execute(): IResult

IDoor+ getStatus(): String

IAlert+ sendAlert(String)


Command設計模式監控系統 Server類別有四個method

• addCommand：傳入ICommand物件註冊，用此物件做監控。• removeCommand：移除ICommand物件。• getCommandSize：傳回註冊的ICommand物件個數。• monitor：逐一呼叫每個向它註冊的ICommand物件之execute方法以執行監控工作。

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public class Server {private List commands;private IAlert alert;public Server(IAlert i) {

alert = i;commands = new ArrayList();

}


Command設計模式監控系統 Server類別有四個method

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public void monitor() {IResult r=null;for (int i=0; i


Command設計模式監控系統 IAlert介面，宣告sendAlert()發送警告。

ICommand介面，宣告execute：監控某特定設備，監控結果以IResult物件表示。

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public interface IAlert {public void sendAlert(String s);public boolean wasAlertSend();

}

public interface ICommand {public IResult execute();

}


Command設計模式監控系統 IDoor介面，宣告getStatus()獲取門的狀態開啟或關閉。

IResult介面有兩個method• getStatus：傳回監控結果，1表示OK，2表示CRITICAL。• getMessage：傳回字串代表監控結果的敘述。

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public interface IResult {public final static int OK=1;public final static int CRITICAL =2;

public String getMessage();public int getStatus();

}

public interface IDoor {public String getStatus();

}


Command設計模式監控系統 DoorCommand類別，監控門是否被打開或關閉。

• 透過IDoor介面判斷門的開啟或關閉狀態。– 不同sensor廠商提供IDoor介面，安裝門上監控。

• execute呼叫_door.getStatus()檢查門的狀態– 回傳「open」代表門被打開，execute函數傳回CRITICAL的

Result物件，將Result物件敘述設為Door is open。

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五種層級Mock物件 Dummy

不做任何事。傳入參數但不會被用到。

Stub 根據輸入參數回傳結果。

Spy 記錄物件的那個成員函數被呼叫，以確認與待測物件互動。

Mock 使用Mock函式庫動態建立，設定資料提供回傳值，或預期要

呼叫的特定成員函式。

Fake 接近原物件但實作較簡單。

例如Alert要傳簡訊，但先實作成存檔。 20


Exercise:未使用Java Mockito Server類別為實作之待測類別，其餘為 mock/stub 物件。

測試Server類別，以及與Server互動的各 stub 物件。最小實作所有mock/stub物件

public class TestServer {private IAlert spyAlert;private Server server;@Beforepublic void setUp() throws Exception {//server = new Server(spy);}@Afterpublic void tearDown() throws Exception {

spyAlert=null;server=null;

}


Exercise:未使用Java Mockito Dummy: 不做任何事。傳入參數但不會被用到。

TestServer.java

public class DummyCommand implements ICommand{public IResult execute(){

throw new RuntimeException("Unimplement");}

}

@Test// Using Dummy Object DummyCommandpublic void testCommandSize() {

server = new Server(null);assertEquals(0, server.getCommandSize());//server.addCommand(null);server.addCommand(new DummyCommand());server.addCommand(new DummyCommand());assertEquals(2, server.getCommandSize());

}


Exercise:未使用Java Mockito Stub: 根據輸入參數回傳結果。

public class StubClosedDoor implements IDoor{public String getStatus() { return "CLOSE"; }

}public class StubOpenDoor implements IDoor{

public String getStatus() { return "OPEN"; }}



public class DoorCommand implements ICommand{private IDoor door;public DoorCommand(IDoor i) { door = i; }public IResult execute() {

String s = door.getStatus();IResult r = null;if (s.startsWith("CLOSE")) {

r = new Result(IResult.OK, "OK");System.out.println("OK~");

} else if (s.startsWith("OPEN")){

r = new Result(IResult.CRITICAL, "OPEN");if (r.getStatus()==IResult.CRITICAL) { System.out.println("HELP~"); }

}return r;

}}



TestServer.java

@Testpublic void testExecuteDoorCommandWhenDoorOpen() {

DoorCommand doorCmd = new DoorCommand(new StubOpenDoor());IResult result = doorCmd.execute();assertEquals(Result.CRITICAL, result.getStatus());assertTrue(result.getMessage().startsWith("OPEN"));

}@Testpublic void testExecuteDoorCommandWhenDoorClosed() {

DoorCommand doorCmd = new DoorCommand(new StubClosedDoor());IResult result = doorCmd.execute();assertEquals(Result.OK, result.getStatus());assertTrue(result.getMessage().startsWith("OK"));

}


Exercise:未使用Java Mockito Spy: 記錄物件的那個method被呼叫，確認與待測物件互動

public class SpyAlert implements IAlert{private boolean sendAlert;public SpyAlert() {

sendAlert = false;}public void sendAlert(String s) {

//System.out.println(s);sendAlert = true;

}public boolean wasAlertSend() {

return sendAlert;}

}


Exercise:未使用Java Mockito Spy: 記錄物件的那個method被呼叫，確認與待測物件互動

TestServer.java@Testpublic void testMonitorSendAlertWhenDoorOpen() {

spyAlert = new SpyAlert();server = new Server(spyAlert);server.addCommand(new DoorCommand(new StubOpenDoor()));server.monitor();assertTrue(spyAlert.wasAlertSend());

}@Testpublic void testMonitorSendAlertWhenDoorClose() {

spyAlert = new SpyAlert(); server = new Server(spyAlert);server.addCommand(new DoorCommand(new StubClosedDoor()));server.monitor();assertFalse(spyAlert.wasAlertSend());

}


Exercise:未使用Java Mockito Fake: 接近原物件但實作較簡單，例如Alert要傳簡訊，但

先實作成存檔。

import java.io.*;public class FakeLogAlert implements IAlert {

private PrintWriter writer;private String fileName;private void close(Closeable c) {

try { c.close(); }catch (IOException e) {

e.printStackTrace(); }

}public FakeLogAlert(String filename)

throws IOException {fileName = filename;

}

public void sendAlert(String msg) {try {

writer = new PrintWriter(fileName, "UTF-8");writer.println(msg);

} catch (FileNotFoundException e) {e.printStackTrace();

}catch (UnsupportedEncodingException e) {

e.printStackTrace();}finally {

close(writer);}

}public boolean wasAlertSend() {

return true;}

}


Exercise:未使用Java Mockito TestServer.java

@Testpublic void testMonitorSendAlertToFakeLogAlertWhenDoorOpen() throws Exception {

IAlert fakeAlert = new FakeLogAlert("OpenFakelog.txt");Server server = new Server(fakeAlert);server.addCommand(new DoorCommand(new StubOpenDoor()));server.monitor();// assert that the OpenFakelog.txt contains a message

}@Testpublic void testMonitorSendAlertToFakeLogAlertWhenDoorClosed() throws Exception {

IAlert fakeAlert = new FakeLogAlert("ClosedFakelog.txt");Server server = new Server(fakeAlert);server.addCommand(new DoorCommand(new StubClosedDoor()));server.monitor();// assert that there is no ClosedFakelog.txt

}}


Exercise:使用 Java Mockito 產生假的ICommand, IAlert, IResult物件，測試

Server.minitor()與IAlert.sendAlert()的互動

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public class TestServer {@Beforepublic void setUp() throws Exception { }@Afterpublic void tearDown() throws Exception { }@Testpublic void TestMockWhenWindowBroken() throws Exception {

ICommand mockCmd = mock(ICommand.class);IAlert mockAlert = mock(IAlert.class);IResult mockResult = mock(IResult.class);Server server = new Server(mockAlert);when(mockCmd.execute()).thenReturn(mockResult);when(mockResult.getStatus()).thenReturn(IResult.CRITICAL);when(mockResult.getMessage()).thenReturn("Broken");server.addCommand(mockCmd);server.monitor();verify(mockAlert, times(1)).sendAlert("Broken");

}


Exercise:使用 Java Mockito 產生假的ICommand, IAlert, IResult物件，測試

Server.minitor()與IAlert.sendAlert()的互動

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@Testpublic void TestMockWhenWindowClose() throws Exception {

ICommand mockCmd = mock(ICommand.class);IAlert mockAlert = mock(IAlert.class);IResult mockResult = mock(IResult.class);Server server = new Server(mockAlert);when(mockCmd.execute()).thenReturn(mockResult);when(mockResult.getStatus()).thenReturn(IResult.OK);server.addCommand(mockCmd);server.monitor();verify(mockAlert, times(0)).sendAlert("Close");

}}

test private method mock object - ntut.edu.twjykuo/train/utmock_30.pdf ·...

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