什么是BDD？

behavior-driven development (BDD)，行为驱动开发。

参考：https://en.wikipedia.org/wiki/Behavior-driven_development

语法区别：

given-willReturn when-thenReturn stub-toReturn

BDDMockito优点：易于阅读

java
    @Test
    public void usingMockito() {
        TodoService todoService = mock(TodoService.class);
        List<String> allTodos = Arrays.asList("Learn Spring MVC",
                "Learn Spring", "Learn to Dance");
        when(todoService.retrieveTodos("Ranga")).thenReturn(allTodos);
        TodoBusinessImpl todoBusinessImpl = new TodoBusinessImpl(todoService);
        List<String> todos = todoBusinessImpl
                .retrieveTodosRelatedToSpring("Ranga");
        assertEquals(2, todos.size());
    }

    @Test
    public void usingMockito_UsingBDD() {
        TodoService todoService = mock(TodoService.class);
        TodoBusinessImpl todoBusinessImpl = new TodoBusinessImpl(todoService);
        List<String> allTodos = Arrays.asList("Learn Spring MVC",
                "Learn Spring", "Learn to Dance");

    //Given - setup
        given(todoService.retrieveTodos("Ranga")).willReturn(allTodos);

        //When - actual method call
        List<String> todos = todoBusinessImpl
                .retrieveTodosRelatedToSpring("Ranga");

        //Then - asserts
        assertThat(todos.size(), is(2));
    }

ai-paddle部署

关键词：[[2023 id=643c3078-da79-43c8

pom

xml
<dependencies>
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>4.12</version>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.mockito</groupId>
			<artifactId>mockito-all</artifactId>
			<version>1.10.19</version>
			<scope>test</scope>
		</dependency>
	</dependencies>

Mock List

java
public class ListTest {

	@Test
	public void letsMockListSize() {
		List list = mock(List.class);
		when(list.size()).thenReturn(10);
		assertEquals(10, list.size());
	}

	@Test
	public void letsMockListSizeWithMultipleReturnValues() {
		List list = mock(List.class);
		when(list.size()).thenReturn(10).thenReturn(20);
		assertEquals(10, list.size()); // First Call
		assertEquals(20, list.size()); // Second Call
	}

	@Test
	public void letsMockListGet() {
		List<String> list = mock(List.class);
		when(list.get(0)).thenReturn("in28Minutes");
		assertEquals("in28Minutes", list.get(0));
		assertNull(list.get(1));
	}

	@Test(expected = RuntimeException.class)
	public void letsMockListGetToThrowException() {
		List<String> list = mock(List.class);
		when(list.get(Mockito.anyInt())).thenThrow(
				new RuntimeException("Something went wrong"));
		list.get(0);
	}

	@Test
	public void letsMockListGetWithAny() {
		List<String> list = mock(List.class);
		Mockito.when(list.get(Mockito.anyInt())).thenReturn("in28Minutes");
		// If you are using argument matchers, all arguments
		// have to be provided by matchers.
		assertEquals("in28Minutes", list.get(0));
		assertEquals("in28Minutes", list.get(1));
	}

	@Test
	public void bddAliases_UsingGivenWillReturn() {
		List<String> list = mock(List.class);

		//given
		given(list.get(Mockito.anyInt())).willReturn("in28Minutes");

		//then
		assertThat("in28Minutes", is(list.get(0)));
		assertThat("in28Minutes", is(list.get(0)));
	}
}

Verify

见转载

Capture Argument

java
	@Test
	public void captureArgument() {
		ArgumentCaptor<String> argumentCaptor = ArgumentCaptor
				.forClass(String.class);

		TodoService todoService = mock(TodoService.class);

		List<String> allTodos = Arrays.asList("Learn Spring MVC",
				"Learn Spring", "Learn to Dance");
		Mockito.when(todoService.retrieveTodos("Ranga")).thenReturn(allTodos);

		TodoBusinessImpl todoBusinessImpl = new TodoBusinessImpl(todoService);
		todoBusinessImpl.deleteTodosNotRelatedToSpring("Ranga");
		Mockito.verify(todoService).deleteTodo(argumentCaptor.capture());

		assertEquals("Learn to Dance", argumentCaptor.getValue());
	}

Hamcrest Matchers

xml
 <dependency>
      <groupId>org.hamcrest</groupId>
      <artifactId>hamcrest-library</artifactId>
      <version>1.3</version>
      <scope>test</scope>
  </dependency>  

java
import static org.hamcrest.CoreMatchers.hasItems;

assertThat(scores, hasSize(4));
assertThat(scores, hasItems(100, 101));
assertThat(scores, everyItem(greaterThan(90)));
assertThat(scores, everyItem(lessThan(200)));

// String
assertThat("", isEmptyString());
assertThat(null, isEmptyOrNullString());