android中单元测试中的断言assert的使用与扩展

首先看一组对比，比如说我们要测试的结果是一个Linearlaout  

AssertJ Android:

assertThat(layout).isVisible()
.isVertical()
.hasChildCount(4)
.hasShowDividers(SHOW_DIVIDERS_MIDDLE);

Regular JUnit:

assertEquals(View.VISIBLE, layout.getVisibility());
assertEquals(VERTICAL, layout.getOrientation());
assertEquals(4, layout.getChildCount());
assertEquals(SHOW_DIVIDERS_MIDDLE, layout.getShowDividers());

Regular AssertJ:

assertThat(layout.getVisibility()).isEqualTo(View.VISIBLE);
assertThat(layout.getOrientation()).isEqualTo(VERTICAL);
assertThat(layout.getChildCount()).isEqualTo(4);
assertThat(layout.getShowDividers()).isEqualTo(SHOW_DIVIDERS_MIDDLE);

从形式上，使用上更加方便。

从输出结果上看，输出结果更加直接可见。

AssertJ Android:     

Expected visibility <gone> but was <invisible>

.

Regular JUnit          Expected:<[8]> but was:<[4]>

Regular AssertJ:     Expected: <8> but was: <4>

所以接下来我们来看看  Assert Android如何来使用。
1首先写一个待测试的数据结构

 public class Draft{
      private String id;//草稿的唯一标识id 

      private String uid ;//发送账号uid，以区别不同账号的草稿

      private int type;//保存的类型

      private String displayedTitle;//展示标题内容

}

2 \首先我们来自定义一个断言类:
   public class DraftAssert extends AbstractAssert<DraftAssert
,Draft>{
      public DraftAssert
(Draft draft){
 
     super(draft,DraftAssert.class);}
}   
   public static DraftAssert
 assertThat(Draft draft){
 
    return new
DraftAssert (draft);}
 
 public DraftAssert  hasDisplayedName(String name){
 
    isNotNull();
 
    if (!draft.getDisplayedTitle().equals(name)){
      failWithMessage(("Expected character's name to be <%s> but was <%s>", name,

draft.getDisplayedTitle());)
      return this;
}
}
3、使用的时候
 
   DraftAssert.assertThat(draft).hasDisplayedName("@罗浩");
 
   如果导入DraftAssert.assertThat静态导入的话，你还可以直接使用
 
   assertThat(draft).hasDisplayedName("@罗浩");