带mockito的inputstreamreader的JUnit测试

您可以使用mockito模拟BufferedReader,如下例所示。

BufferedReader bufferedReader = Mockito.mock(BufferedReader.class);
Mockito.when(bufferedReader.readLine()).thenReturn("1", "2", "3");
// You can mock the result based on the type of result you are expecting.

1. 提取 reader 作为一个领域。(您可以直接或在构造函数中初始化它)

   private final BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
   

2. 定义getter(或者 public 或 protected )

   protected BufferedReader getReader(){
       return reader;
   }
   

3. 删除的初始化 new BufferedReader(...) 从你的方法。使用 getReader() 相反。

   public Cell readInput() {
       try {
           System.out.print("Enter the co-ordinate Seperated by Comma");
           String coOrdinates = getReader().readLine();
           String[] values=coOrdinates.split("\\,");
           return new Cell(Integer.parseInt(values[0]),Integer.parseInt(values[1]));
       } catch (IOException ioe) {
           ioe.printStackTrace();
       }
       return null;
   }
   

4. 在测试类中,初始化 ConsoleReader 作为 Mockito.spy

   ConsoleReader consoleReader = spy(new ConsoleReader());
   

5. 嘲笑你的能手

   @Before
   public void setUp() {
       BufferedReader bufferedReader = mock(BufferedReader.class);
       doReturn(bufferedReader).when(consoleReader).getReader();
       doCallRealMethod().when(consoleReader).readInput();
   }
   

6. 定义测试:

   @Test
   public void testReadInput() {
       when(bufferedReader.readLine()).thenReturn("123,456");
   
       Cell expectedCell = new Cell(123, 456);
       Cell actualCell = consoleReader.readInput();
   
       assertEquals(expectedCell, actualCell);   
   }