Overview

How to mock each case with Mockito 1x https://qiita.com/taka_22/items/0c13aacf6ffbc2c77970 Continued.

Premise

Mockito 1.10.19 PowerMock 1.7.3 JUnit 4.11 Java 1.8.0_151

Case

Handles cases where dependent objects are created with new, static methods, and private methods. Based on the previous pattern, we classified it into the following 12 patterns.

No	pattern	Return type of mock target method	Mock range	Mock operation
7	The class you want to mock is generated with new	Other than void	The entire	Returns the specified return value
8	The class you want to mock is generated with new	Other than void	The entire	Throw an exception
9	The class you want to mock is generated with new	void	The entire	Throw an exception
10	Mock target is static method	Other than void	The entire	Returns the specified return value
11	Mock target is static method	Other than void	The entire	Throw an exception
12	Mock target is static method	void	The entire	Throw an exception
13	Mock target is private method	Other than void	The entire	Returns the specified return value
14	Mock target is private method	Other than void	The entire	Throw an exception
15	Mock target is private method	void	The entire	Throw an exception
16	Mock target is private method	Other than void	Only some methods	Returns the specified return value
17	Mock target is private method	Other than void	Only some methods	Throw an exception
18	Mock target is private method	void	Only some methods	Throw an exception

Class created for testing

DateUtil.java import java.text.SimpleDateFormat; import java.util.Date; public class DateUtil { private Boolean flag; public static String getCurrentDate() { Date d = new Date(); return new SimpleDateFormat("yyyy/MM/dd").format(d); } public static void setCurrentDate(long currentTime) { Date d = new Date(); d.setTime(currentTime); } public String getYYYYMMDDStringWrapper(Date date) throws Exception { return getYYYYMMDDString(date); } private String getYYYYMMDDString(Date date) throws Exception { return new SimpleDateFormat("yyyyMMdd").format(date); } private void setFlag(Boolean flag) throws Exception { this.flag = flag; } }

How to write a test

How to write a test in PowerMock

The methods used in Mockito, such as mock / spy / doThrow, must be dedicated to PowerMock.
Specify PowerMockRunner with @RunWith
Specify the mock target test with @PrepareForTest

import static org.powermock.api.mockito.PowerMockito.doThrow; import static org.powermock.api.mockito.PowerMockito.mock; import static org.powermock.api.mockito.PowerMockito.spy; import static org.powermock.api.mockito.PowerMockito.whenNew;

@RunWith(PowerMockRunner.class) @PrepareForTest({ DateUtil.class }) public class PowerMockTest { ...

No.7 Makes whenNew return a mock of the object created by new.

/**

Objects generated by new, public methods, return types are all mock except void, return values */ @Test public void test007() throws Exception { // Expected value is 2015/05/05 Calendar c = Calendar.getInstance(); c.set(2015, 4, 5); Date expected = c.getTime();

// Recording phase Date dateMocked = mock(Date.class); whenNew(Date.class).withNoArguments().thenReturn(dateMocked); when(dateMocked.getTime()).thenReturn(expected.getTime());

// Replay phase String strDate = DateUtil.getCurrentDate();

// Verification phase assertThat(strDate, is("2015/05/05")); }

No.8 /**

Objects generated by new, public methods, return types are all mock except void, throw exceptions */ @Test public void test008() throws Exception { // Recording phase Date dateMocked = mock(Date.class); whenNew(Date.class).withNoArguments().thenReturn(dateMocked); when(dateMocked.getTime()).thenThrow(new RuntimeException("aaa"));

// Replay & Verification Phase try { DateUtil.getCurrentDate(); fail(); } catch (RuntimeException e) { assertThat(e.getMessage(), is("aaa")); } }

No.9 /**

Object created by new, public method, return type is void, all mock, throw exception */ @Test public void test009() throws Exception { // Recording phase Date dateMocked = mock(Date.class); whenNew(Date.class).withNoArguments().thenReturn(dateMocked); doThrow(new RuntimeException("bbb")).when(dateMocked).setTime(anyLong());

// Replay & Verification Phase try { DateUtil.setCurrentDate(123456789L); fail(); } catch (RuntimeException e) { assertThat(e.getMessage(), is("bbb")); } }

No.10 Mock static methods with mockStatic.

/**

public static method, return type is mock all except void, return value */ @Test public void test010() { // Recording phase PowerMockito.mockStatic(String.class); PowerMockito.when(String.valueOf(anyBoolean())).thenReturn("false");

// Replay & Verification Phase assertThat(String.valueOf(true), is("false")); assertThat(String.valueOf(false), is("false")); }

No.11 /**

public static method, return type is void except void, all mock, throw exception */ @Test public void test011() { // Recording phase PowerMockito.mockStatic(String.class); PowerMockito.when(String.valueOf(true)).thenThrow(new RuntimeException("aaa"));

// Replay & Verification Phase try { String.valueOf(true); fail(); } catch (RuntimeException e) { assertThat(e.getMessage(), is("aaa")); } assertNull(String.valueOf(false)); }

No.12 /**

public static method, return type void, all mock, throw exception */ @Test public void test012() { // Recording phase PowerMockito.mockStatic(DateUtil.class); try { doThrow(new RuntimeException("bbb")).when(DateUtil.class, "setCurrentDate", anyLong()); } catch (Exception e) { fail(); }

// Replay & Verification Phase try { DateUtil.setCurrentDate(12345L); fail(); } catch (RuntimeException e) { assertThat(e.getMessage(), is("bbb")); } }

No.13 Since it mock the whole, the mocked method is called directly by reflection.

/**

Private method, return type is mock all except void, return value */ @Test public void test013() throws Exception { // Recording phase DateUtil dateMocked = mock(DateUtil.class); PowerMockito.when(dateMocked, "getYYYYMMDDString", (Date) any()).thenReturn("12345678");

// Replay phase Method getYYYYMMDDStringMethod = DateUtil.class.getDeclaredMethod("getYYYYMMDDString", Date.class); getYYYYMMDDStringMethod.setAccessible(true); String actual = (String)getYYYYMMDDStringMethod.invoke(dateMocked, new Date());

// Verification phase assertThat(actual, is("12345678")); }

No.14 /**

Private method, return type is void except void, all mock, throw exception */ @Test public void test014() throws Exception { // Recording phase DateUtil dateMocked = mock(DateUtil.class); PowerMockito.when(dateMocked, "getYYYYMMDDString", (Date) any()).thenThrow(new Exception("aaa"));

// Replay & Verification Phase try { Method getYYYYMMDDStringMethod = DateUtil.class.getDeclaredMethod("getYYYYMMDDString", Date.class); getYYYYMMDDStringMethod.setAccessible(true); getYYYYMMDDStringMethod.invoke(dateMocked, new Date()); fail(); } catch (Exception e) { if (e instanceof InvocationTargetException) { InvocationTargetException ite = (InvocationTargetException) e; assertThat(ite.getTargetException().getMessage(), is("aaa")); } else { fail(); } } }

No.15 /**

private method, return type void, all mock, throw exception */ @Test public void test015() throws Exception { // Recording phase DateUtil dateMocked = mock(DateUtil.class); PowerMockito.doThrow(new Exception("bbb")).when(dateMocked, "setFlag", anyBoolean());

// Replay & Verification Phase Method setFlagMethod = DateUtil.class.getDeclaredMethod("setFlag", Boolean.class); setFlagMethod.setAccessible(true); try { setFlagMethod.invoke(dateMocked, true); fail(); } catch (Exception e) { if (e instanceof InvocationTargetException) { InvocationTargetException ite = (InvocationTargetException) e; assertThat(ite.getTargetException().getMessage(), is("bbb")); } else { fail(); } } }

No.16 The only difference in how to mock is to use spy. The rest is the same as No.13-15. It doesn't mock everything, so you can test it via public methods. Of course, reflection is also possible. /**

Private method, return type is other than void, some mock, return value */ @Test public void test016() throws Exception { // Recording phase DateUtil dateMocked = spy(new DateUtil()); PowerMockito.doReturn("12345678").when(dateMocked, "getYYYYMMDDString", (Date) any());

// Replay phase String strDate = dateMocked.getYYYYMMDDStringWrapper(new Date());

// Verification phase assertThat(strDate, is("12345678")); }

No.17 /**

Private method, return type is void except void, some mock, throw exception */ @Test public void test017() throws Exception { // Recording phase DateUtil dateMocked = spy(new DateUtil()); PowerMockito.doThrow(new RuntimeException("aaa")).when(dateMocked, "getYYYYMMDDString", (Date) any());

// Replay & Verification Phase try { dateMocked.getYYYYMMDDStringWrapper(new Date()); fail(); } catch (RuntimeException e) { assertThat(e.getMessage(), is("aaa")); } }

No.18 /**

private method, return type void, some mock, throw exception */ @Test public void test018() throws Exception { // Recording phase DateUtil dateMocked = spy(new DateUtil()); PowerMockito.doThrow(new Exception("bbb")).when(dateMocked, "setFlag", anyBoolean());

reference

Mockito http://site.mockito.org/ PowerMock https://github.com/powermock/powermock

Project confirmed to work

https://github.com/taka2/mockito-sample

How to mock each case with Mockito 1x

https://qiita.com/taka_22/items/0c13aacf6ffbc2c77970

[JAVA] How to mock each case with PowerMock + Mockito1x