Config Mock (Unit Test past 2)

Wednesday, 20/11/2019

Tram Ho

1. when and thenReturn

Mock can return different values depending on the parameters you pass in the method. When and Then Return are a sequence of methods used to specify the return value for a method call with pre-defined parameters.

Example

      @Test
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">test1</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span>  <span class="token punctuation">{</span>
        <span class="token comment">//  create mock</span>
        MyClass test <span class="token operator">=</span> <span class="token function">mock</span> <span class="token punctuation">(</span> MyClass <span class="token punctuation">.</span> <span class="token keyword">class</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

        <span class="token comment">// define return value for method getUniqueId()</span>
        <span class="token function">when</span> <span class="token punctuation">(</span> test <span class="token punctuation">.</span> <span class="token function">getUniqueId</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">thenReturn</span> <span class="token punctuation">(</span> <span class="token number">43</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

        <span class="token comment">// use mock in test....</span>
        <span class="token function">assertEquals</span> <span class="token punctuation">(</span> test <span class="token punctuation">.</span> <span class="token function">getUniqueId</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">,</span> <span class="token number">43</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token punctuation">}</span>


<span class="token comment">// demonstrates the return of multiple values</span>
@Test
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">testMoreThanOneReturnValue</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span>  <span class="token punctuation">{</span>
        Iterator <span class="token operator">&lt;</span> String <span class="token operator">&gt;</span> i <span class="token operator">=</span> <span class="token function">mock</span> <span class="token punctuation">(</span> Iterator <span class="token punctuation">.</span> <span class="token keyword">class</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
        <span class="token function">when</span> <span class="token punctuation">(</span> i <span class="token punctuation">.</span> <span class="token function">next</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">thenReturn</span> <span class="token punctuation">(</span> <span class="token string">"Mockito"</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">thenReturn</span> <span class="token punctuation">(</span> <span class="token string">"rocks"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
        String result <span class="token operator">=</span> i <span class="token punctuation">.</span> <span class="token function">next</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token operator">+</span> <span class="token string">" "</span> <span class="token operator">+</span> i <span class="token punctuation">.</span> <span class="token function">next</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
        <span class="token comment">//assert</span>
        <span class="token function">assertEquals</span> <span class="token punctuation">(</span> <span class="token string">"Mockito rocks"</span> <span class="token punctuation">,</span> result <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token comment">// this test demonstrates how to return values based on the input</span>
@Test
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">testReturnValueDependentOnMethodParameter</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span>  <span class="token punctuation">{</span>
        Comparable <span class="token operator">&lt;</span> String <span class="token operator">&gt;</span> c <span class="token operator">=</span> <span class="token function">mock</span> <span class="token punctuation">(</span> Comparable <span class="token punctuation">.</span> <span class="token keyword">class</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
        <span class="token function">when</span> <span class="token punctuation">(</span> c <span class="token punctuation">.</span> <span class="token function">compareTo</span> <span class="token punctuation">(</span> <span class="token string">"Mockito"</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">thenReturn</span> <span class="token punctuation">(</span> <span class="token number">1</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
        <span class="token function">when</span> <span class="token punctuation">(</span> c <span class="token punctuation">.</span> <span class="token function">compareTo</span> <span class="token punctuation">(</span> <span class="token string">"Eclipse"</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">thenReturn</span> <span class="token punctuation">(</span> <span class="token number">2</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
        <span class="token comment">//assert</span>
        <span class="token function">assertEquals</span> <span class="token punctuation">(</span> <span class="token number">1</span> <span class="token punctuation">,</span> c <span class="token punctuation">.</span> <span class="token function">compareTo</span> <span class="token punctuation">(</span> <span class="token string">"Mockito"</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token comment">// this test demonstrates how to return values independent of the input value</span>

@Test
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">testReturnValueInDependentOnMethodParameter</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span>  <span class="token punctuation">{</span>
        Comparable <span class="token operator">&lt;</span> Integer <span class="token operator">&gt;</span> c <span class="token operator">=</span> <span class="token function">mock</span> <span class="token punctuation">(</span> Comparable <span class="token punctuation">.</span> <span class="token keyword">class</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
        <span class="token function">when</span> <span class="token punctuation">(</span> c <span class="token punctuation">.</span> <span class="token function">compareTo</span> <span class="token punctuation">(</span> <span class="token function">anyInt</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">thenReturn</span> <span class="token punctuation">(</span> <span class="token operator">-</span> <span class="token number">1</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
        <span class="token comment">//assert</span>
        <span class="token function">assertEquals</span> <span class="token punctuation">(</span> <span class="token operator">-</span> <span class="token number">1</span> <span class="token punctuation">,</span> c <span class="token punctuation">.</span> <span class="token function">compareTo</span> <span class="token punctuation">(</span> <span class="token number">9</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token comment">// return a value based on the type of the provide parameter</span>

@Test
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">testReturnValueInDependentOnMethodParameter2</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span>  <span class="token punctuation">{</span>
        Comparable <span class="token operator">&lt;</span> Todo <span class="token operator">&gt;</span> c <span class="token operator">=</span> <span class="token function">mock</span> <span class="token punctuation">(</span> Comparable <span class="token punctuation">.</span> <span class="token keyword">class</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
        <span class="token function">when</span> <span class="token punctuation">(</span> c <span class="token punctuation">.</span> <span class="token function">compareTo</span> <span class="token punctuation">(</span> <span class="token function">isA</span> <span class="token punctuation">(</span> Todo <span class="token punctuation">.</span> <span class="token keyword">class</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">thenReturn</span> <span class="token punctuation">(</span> <span class="token number">0</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
        <span class="token comment">//assert</span>
        <span class="token function">assertEquals</span> <span class="token punctuation">(</span> <span class="token number">0</span> <span class="token punctuation">,</span> c <span class="token punctuation">.</span> <span class="token function">compareTo</span> <span class="token punctuation">(</span> <span class="token keyword">new</span> <span class="token class-name">Todo</span> <span class="token punctuation">(</span> <span class="token number">1</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token punctuation">}</span>


When and then Return có thể <span class="token keyword">throw</span> một exeption 

Properties properties <span class="token operator">=</span> <span class="token function">mock</span> <span class="token punctuation">(</span> Properties <span class="token punctuation">.</span> <span class="token keyword">class</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

<span class="token function">when</span> <span class="token punctuation">(</span> properties <span class="token punctuation">.</span> <span class="token keyword">get</span> <span class="token punctuation">(</span> ”Anddroid” <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">thenThrow</span> <span class="token punctuation">(</span> <span class="token keyword">new</span> <span class="token class-name">IllegalArgumentException</span> <span class="token punctuation">(</span> <span class="token operator">...</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

<span class="token keyword">try</span> <span class="token punctuation">{</span>
    properties <span class="token punctuation">.</span> <span class="token keyword">get</span> <span class="token punctuation">(</span> ”Anddroid” <span class="token punctuation">)</span> <span class="token punctuation">;</span>
    <span class="token function">fail</span> <span class="token punctuation">(</span> ”Anddroid is misspelled” <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span> <span class="token class-name">IllegalArgumentException</span> ex <span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token comment">// good!</span>
<span class="token punctuation">}</span>

@Test

public void test1 ( ) {

// create mock

MyClass test = mock ( MyClass . class ) ;

// define return value for method getUniqueId()

when ( test . getUniqueId ( ) ) . thenReturn ( 43 ) ;

// use mock in test....

assertEquals ( test . getUniqueId ( ) , 43 ) ;

}

// demonstrates the return of multiple values

@Test

public void testMoreThanOneReturnValue ( ) {

Iterator < String > i = mock ( Iterator . class ) ;

when ( i . next ( ) ) . thenReturn ( "Mockito" ) . thenReturn ( "rocks" ) ;

String result = i . next ( ) + " " + i . next ( ) ;

//assert

assertEquals ( "Mockito rocks" , result ) ;

}

// this test demonstrates how to return values based on the input

@Test

public void testReturnValueDependentOnMethodParameter ( ) {

Comparable < String > c = mock ( Comparable . class ) ;

when ( c . compareTo ( "Mockito" ) ) . thenReturn ( 1 ) ;

when ( c . compareTo ( "Eclipse" ) ) . thenReturn ( 2 ) ;

//assert

assertEquals ( 1 , c . compareTo ( "Mockito" ) ) ;

}

// this test demonstrates how to return values independent of the input value

@Test

public void testReturnValueInDependentOnMethodParameter ( ) {

Comparable < Integer > c = mock ( Comparable . class ) ;

when ( c . compareTo ( anyInt ( ) ) ) . thenReturn ( - 1 ) ;

//assert

assertEquals ( - 1 , c . compareTo ( 9 ) ) ;

}

// return a value based on the type of the provide parameter

@Test

public void testReturnValueInDependentOnMethodParameter2 ( ) {

Comparable < Todo > c = mock ( Comparable . class ) ;

when ( c . compareTo ( isA ( Todo . class ) ) ) . thenReturn ( 0 ) ;

//assert

assertEquals ( 0 , c . compareTo ( new Todo ( 1 ) ) ) ;

}

When and then Return có thể throw một exeption

Properties properties = mock ( Properties . class ) ;

when ( properties . get ( ”Anddroid” ) ) . thenThrow ( new IllegalArgumentException ( ... ) ) ;

try {

properties . get ( ”Anddroid” ) ;

fail ( ”Anddroid is misspelled” ) ;

} catch ( IllegalArgumentException ex ) {

// good!

}

The When and ThenReturn method string may return an exeption
Example

Properties properties <span class="token operator">=</span> <span class="token function">mock</span> <span class="token punctuation">(</span> Properties <span class="token punctuation">.</span> <span class="token keyword">class</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

<span class="token function">when</span> <span class="token punctuation">(</span> properties <span class="token punctuation">.</span> <span class="token keyword">get</span> <span class="token punctuation">(</span> ”Anddroid” <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">thenThrow</span> <span class="token punctuation">(</span> <span class="token keyword">new</span> <span class="token class-name">IllegalArgumentException</span> <span class="token punctuation">(</span> <span class="token operator">...</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

<span class="token keyword">try</span> <span class="token punctuation">{</span>
   properties <span class="token punctuation">.</span> <span class="token keyword">get</span> <span class="token punctuation">(</span> ”Anddroid” <span class="token punctuation">)</span> <span class="token punctuation">;</span>
   <span class="token function">fail</span> <span class="token punctuation">(</span> ”Anddroid is misspelled” <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span> <span class="token class-name">IllegalArgumentException</span> ex <span class="token punctuation">)</span> <span class="token punctuation">{</span>
   <span class="token comment">// good!</span>
<span class="token punctuation">}</span>

try {

fail ( ”Anddroid is misspelled” ) ;

// good!

}

2. “doReturn When” and “doThrow When”

doReturn () .. When () is similar to when () .. thenReturn (). It is very useful in creating mock methods to create exceptions during the Example test

Properties properties <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Properties</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

Properties spyProperties <span class="token operator">=</span> <span class="token function">spy</span> <span class="token punctuation">(</span> properties <span class="token punctuation">)</span> <span class="token punctuation">;</span>

<span class="token function">doReturn</span> <span class="token punctuation">(</span> “ <span class="token number">42</span> ” <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">when</span> <span class="token punctuation">(</span> spyProperties <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token keyword">get</span> <span class="token punctuation">(</span> ”shoeSize” <span class="token punctuation">)</span> <span class="token punctuation">;</span>

String value <span class="token operator">=</span> spyProperties <span class="token punctuation">.</span> <span class="token keyword">get</span> <span class="token punctuation">(</span> ”shoeSize” <span class="token punctuation">)</span> <span class="token punctuation">;</span>

<span class="token function">assertEquals</span> <span class="token punctuation">(</span> ” <span class="token number">42</span> ” <span class="token punctuation">,</span> value <span class="token punctuation">)</span> <span class="token punctuation">;</span>

Properties properties = new Properties ( ) ;

Properties spyProperties = spy ( properties ) ;

doReturn ( “ 42 ” ) . when ( spyProperties ) . get ( ”shoeSize” ) ;

String value = spyProperties . get ( ”shoeSize” ) ;

assertEquals ( ” 42 ” , value ) ;

doThrow is used to return an exeption.
Example

Properties properties <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Properties</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

Properties spyProperties <span class="token operator">=</span> <span class="token function">spy</span> <span class="token punctuation">(</span> properties <span class="token punctuation">)</span> <span class="token punctuation">;</span>

<span class="token function">doReturn</span> <span class="token punctuation">(</span> “ <span class="token number">42</span> ” <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">when</span> <span class="token punctuation">(</span> spyProperties <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token keyword">get</span> <span class="token punctuation">(</span> ”shoeSize” <span class="token punctuation">)</span> <span class="token punctuation">;</span>

String value <span class="token operator">=</span> spyProperties <span class="token punctuation">.</span> <span class="token keyword">get</span> <span class="token punctuation">(</span> ”shoeSize” <span class="token punctuation">)</span> <span class="token punctuation">;</span>

<span class="token function">assertEquals</span> <span class="token punctuation">(</span> ” <span class="token number">42</span> ” <span class="token punctuation">,</span> value <span class="token punctuation">)</span> <span class="token punctuation">;</span>

3. Wrapping a Java object with Spy

@Spy or spy () method can be used to wrap a real object.
Example

<span class="token keyword">var</span> s <span class="token operator">=</span> <span class="token string">'Syntax Highlighting'</span> <span class="token punctuation">;</span>
<span class="token template-string"><span class="token string">``</span></span> ` <span class="token keyword">import</span> <span class="token keyword">static</span> org <span class="token punctuation">.</span> mockito <span class="token punctuation">.</span> Mockito <span class="token punctuation">.</span> <span class="token operator">*</span> <span class="token punctuation">;</span>

@Test
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">testLinkedListSpyWrong</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token comment">// Lets mock a LinkedList</span>
    List <span class="token operator">&lt;</span> String <span class="token operator">&gt;</span> list <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">LinkedList</span> <span class="token operator">&lt;</span> <span class="token operator">&gt;</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
    List <span class="token operator">&lt;</span> String <span class="token operator">&gt;</span> spy <span class="token operator">=</span> <span class="token function">spy</span> <span class="token punctuation">(</span> list <span class="token punctuation">)</span> <span class="token punctuation">;</span>

    <span class="token comment">// this does not work</span>
    <span class="token comment">// real method is called so spy.get(0)</span>
    <span class="token comment">// throws IndexOutOfBoundsException (list is still empty)</span>
    <span class="token function">when</span> <span class="token punctuation">(</span> spy <span class="token punctuation">.</span> <span class="token keyword">get</span> <span class="token punctuation">(</span> <span class="token number">0</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">thenReturn</span> <span class="token punctuation">(</span> <span class="token string">"foo"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

    <span class="token function">assertEquals</span> <span class="token punctuation">(</span> <span class="token string">"foo"</span> <span class="token punctuation">,</span> spy <span class="token punctuation">.</span> <span class="token keyword">get</span> <span class="token punctuation">(</span> <span class="token number">0</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token punctuation">}</span>

@Test
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">testLinkedListSpyCorrect</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token comment">// Lets mock a LinkedList</span>
    List <span class="token operator">&lt;</span> String <span class="token operator">&gt;</span> list <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">LinkedList</span> <span class="token operator">&lt;</span> <span class="token operator">&gt;</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
    List <span class="token operator">&lt;</span> String <span class="token operator">&gt;</span> spy <span class="token operator">=</span> <span class="token function">spy</span> <span class="token punctuation">(</span> list <span class="token punctuation">)</span> <span class="token punctuation">;</span>

    <span class="token comment">// You have to use doReturn() for stubbing</span>
    <span class="token function">doReturn</span> <span class="token punctuation">(</span> <span class="token string">"foo"</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">when</span> <span class="token punctuation">(</span> spy <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token keyword">get</span> <span class="token punctuation">(</span> <span class="token number">0</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

    <span class="token function">assertEquals</span> <span class="token punctuation">(</span> <span class="token string">"foo"</span> <span class="token punctuation">,</span> spy <span class="token punctuation">.</span> <span class="token keyword">get</span> <span class="token punctuation">(</span> <span class="token number">0</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token punctuation">}</span>

var s = 'Syntax Highlighting' ;

`` ` import static org . mockito . Mockito . * ;

@Test

public void testLinkedListSpyWrong ( ) {

// Lets mock a LinkedList

List < String > list = new LinkedList < > ( ) ;

List < String > spy = spy ( list ) ;

// this does not work

// real method is called so spy.get(0)

// throws IndexOutOfBoundsException (list is still empty)

when ( spy . get ( 0 ) ) . thenReturn ( "foo" ) ;

assertEquals ( "foo" , spy . get ( 0 ) ) ;

}

@Test

public void testLinkedListSpyCorrect ( ) {

// Lets mock a LinkedList

// You have to use doReturn() for stubbing

doReturn ( "foo" ) . when ( spy ) . get ( 0 ) ;

}

4. Veryfy the call on the mock object

Mockito keeps track of all method calls and parameters of a Mock object. Use verify () on Mock objects to verify that the specified conditions have been met.
example

<span class="token keyword">import</span> <span class="token keyword">static</span> org <span class="token punctuation">.</span> mockito <span class="token punctuation">.</span> Mockito <span class="token punctuation">.</span> <span class="token operator">*</span> <span class="token punctuation">;</span>

@Test
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">testVerify</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span>  <span class="token punctuation">{</span>
    <span class="token comment">// create and configure mock</span>
    MyClass test <span class="token operator">=</span> Mockito <span class="token punctuation">.</span> <span class="token function">mock</span> <span class="token punctuation">(</span> MyClass <span class="token punctuation">.</span> <span class="token keyword">class</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
    <span class="token function">when</span> <span class="token punctuation">(</span> test <span class="token punctuation">.</span> <span class="token function">getUniqueId</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">thenReturn</span> <span class="token punctuation">(</span> <span class="token number">43</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>


    <span class="token comment">// call method testing on the mock with parameter 12</span>
    test <span class="token punctuation">.</span> <span class="token function">testing</span> <span class="token punctuation">(</span> <span class="token number">12</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
    test <span class="token punctuation">.</span> <span class="token function">getUniqueId</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
    test <span class="token punctuation">.</span> <span class="token function">getUniqueId</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>


    <span class="token comment">// now check if method testing was called with the parameter 12</span>
    <span class="token function">verify</span> <span class="token punctuation">(</span> test <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">testing</span> <span class="token punctuation">(</span> ArgumentMatchers <span class="token punctuation">.</span> <span class="token function">eq</span> <span class="token punctuation">(</span> <span class="token number">12</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

    <span class="token comment">// was the method called twice?</span>
    <span class="token function">verify</span> <span class="token punctuation">(</span> test <span class="token punctuation">,</span> <span class="token function">times</span> <span class="token punctuation">(</span> <span class="token number">2</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">getUniqueId</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

    <span class="token comment">// other alternatives for verifiying the number of method calls for a method</span>
    <span class="token function">verify</span> <span class="token punctuation">(</span> test <span class="token punctuation">,</span> <span class="token function">never</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">someMethod</span> <span class="token punctuation">(</span> <span class="token string">"never called"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
    <span class="token function">verify</span> <span class="token punctuation">(</span> test <span class="token punctuation">,</span> <span class="token function">atLeastOnce</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">someMethod</span> <span class="token punctuation">(</span> <span class="token string">"called at least once"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
    <span class="token function">verify</span> <span class="token punctuation">(</span> test <span class="token punctuation">,</span> <span class="token function">atLeast</span> <span class="token punctuation">(</span> <span class="token number">2</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">someMethod</span> <span class="token punctuation">(</span> <span class="token string">"called at least twice"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
    <span class="token function">verify</span> <span class="token punctuation">(</span> test <span class="token punctuation">,</span> <span class="token function">times</span> <span class="token punctuation">(</span> <span class="token number">5</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">someMethod</span> <span class="token punctuation">(</span> <span class="token string">"called five times"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
    <span class="token function">verify</span> <span class="token punctuation">(</span> test <span class="token punctuation">,</span> <span class="token function">atMost</span> <span class="token punctuation">(</span> <span class="token number">3</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">someMethod</span> <span class="token punctuation">(</span> <span class="token string">"called at most 3 times"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
    <span class="token comment">// This let's you check that no other methods where called on this object.</span>
    <span class="token comment">// You call it after you have verified the expected method calls.</span>
    <span class="token function">verifyNoMoreInteractions</span> <span class="token punctuation">(</span> test <span class="token punctuation">)</span> <span class="token punctuation">;</span>
<span class="token punctuation">}</span>

import static org . mockito . Mockito . * ;

@Test

public void testVerify ( ) {

// create and configure mock

MyClass test = Mockito . mock ( MyClass . class ) ;

// call method testing on the mock with parameter 12

test . testing ( 12 ) ;

test . getUniqueId ( ) ;

// now check if method testing was called with the parameter 12

verify ( test ) . testing ( ArgumentMatchers . eq ( 12 ) ) ;

// was the method called twice?

verify ( test , times ( 2 ) ) . getUniqueId ( ) ;

// other alternatives for verifiying the number of method calls for a method

verify ( test , never ( ) ) . someMethod ( "never called" ) ;

verify ( test , atLeastOnce ( ) ) . someMethod ( "called at least once" ) ;

verify ( test , atLeast ( 2 ) ) . someMethod ( "called at least twice" ) ;

verify ( test , times ( 5 ) ) . someMethod ( "called five times" ) ;

verify ( test , atMost ( 3 ) ) . someMethod ( "called at most 3 times" ) ;

// This let's you check that no other methods where called on this object.

// You call it after you have verified the expected method calls.

verifyNoMoreInteractions ( test ) ;

}

5. Use @InjectMock to create dependencies via Mockito

Annotation @InjectMock implements constructors, methods, and fields depending on its type
example

<span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">ArticleManager</span> <span class="token punctuation">{</span>
    <span class="token keyword">private</span> User user <span class="token punctuation">;</span>
    <span class="token keyword">private</span> ArticleDatabase database <span class="token punctuation">;</span>

    <span class="token keyword">public</span> <span class="token function">ArticleManager</span> <span class="token punctuation">(</span> User user <span class="token punctuation">,</span> ArticleDatabase database <span class="token punctuation">)</span> <span class="token punctuation">{</span>
        <span class="token keyword">super</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
        <span class="token keyword">this</span> <span class="token punctuation">.</span> user <span class="token operator">=</span> user <span class="token punctuation">;</span>
        <span class="token keyword">this</span> <span class="token punctuation">.</span> database <span class="token operator">=</span> database <span class="token punctuation">;</span>
    <span class="token punctuation">}</span>

    <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">initialize</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">{</span>
        database <span class="token punctuation">.</span> <span class="token function">addListener</span> <span class="token punctuation">(</span> <span class="token keyword">new</span> <span class="token class-name">ArticleListener</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
    <span class="token punctuation">}</span>
<span class="token punctuation">}</span>

public class ArticleManager {

private User user ;

private ArticleDatabase database ;

public ArticleManager ( User user , ArticleDatabase database ) {

super ( ) ;

this . user = user ;

this . database = database ;

}

public void initialize ( ) {

database . addListener ( new ArticleListener ( ) ) ;

}

The above class is constructed via Mockito and its dependencies are expressed by Mock example objects

@ <span class="token function">RunWith</span> <span class="token punctuation">(</span> MockitoJUnitRunner <span class="token punctuation">.</span> <span class="token keyword">class</span> <span class="token punctuation">)</span>
<span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">ArticleManagerTest</span>  <span class="token punctuation">{</span>

       @Mock ArticleCalculator calculator <span class="token punctuation">;</span>
       @Mock ArticleDatabase database <span class="token punctuation">;</span>
       @Mock User user <span class="token punctuation">;</span>

       @Spy <span class="token keyword">private</span> UserProvider userProvider <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ConsumerUserProvider</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

       @InjectMocks <span class="token keyword">private</span> ArticleManager manager <span class="token punctuation">;</span> 

       @Test <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">shouldDoSomething</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">{</span>
           <span class="token comment">// calls addListener with an instance of ArticleListener</span>
           manager <span class="token punctuation">.</span> <span class="token function">initialize</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>

           <span class="token comment">// validate that addListener was called</span>
           <span class="token function">verify</span> <span class="token punctuation">(</span> database <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">addListener</span> <span class="token punctuation">(</span> <span class="token function">any</span> <span class="token punctuation">(</span> ArticleListener <span class="token punctuation">.</span> <span class="token keyword">class</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span>
       <span class="token punctuation">}</span>
<span class="token punctuation">}</span>

@ RunWith ( MockitoJUnitRunner . class )

public class ArticleManagerTest {

@Mock ArticleCalculator calculator ;

@Mock ArticleDatabase database ;

@Mock User user ;

@Spy private UserProvider userProvider = new ConsumerUserProvider ( ) ;

@InjectMocks private ArticleManager manager ;

@Test public void shouldDoSomething ( ) {

// calls addListener with an instance of ArticleListener

manager . initialize ( ) ;

// validate that addListener was called

verify ( database ) . addListener ( any ( ArticleListener . class ) ) ;

}

Mockito can inject an object by Inject constructor, setter or properties.

6. References

https://www.vogella.com/tutorials/Mockito/article.html

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Source : Viblo

Config Mock (Unit Test past 2)

1. when and thenReturn

2. “doReturn When” and “doThrow When”

3. Wrapping a Java object with Spy

4. Veryfy the call on the mock object

5. Use @InjectMock to create dependencies via Mockito

6. References

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