Simulation of JUnit output for the given input

Question

public void MyTest {
 @Rule
   public final TextFromStandardInputStream systemInMock
  = emptyStandardInputStream();

 @Test
 public void shouldTakeUserInput() {
    systemInMock.provideLines("add 5", "another line");
     InputOutput inputOutput = new InputOutput();
    assertEquals("add 5", inputOutput.getInput());
 }
}

Here, I want to check for the input add 5 my output should some statement using System.out.println() statement within some method. Is It possible to simulate output statement?

score 3 · Accepted Answer · answered Oct 24 '17 at 06:14

3

You can use the SystemOutRule to get the output written to System.out and assert against it:

public class MyTest {
    @Rule
    public final TextFromStandardInputStream systemInMock = 
        emptyStandardInputStream();

    @Rule
    public final SystemOutRule systemOutRule = new SystemOutRule().enableLog();

    @Test
    public void shouldTakeUserInput() {
        systemInMock.provideLines("add 5", "another line");

        MyCode myCode = new MyCode();
        myCode.doSomething();

        assertEquals("expected output", systemOutRule.getLog());
    }
}

answered Oct 24 '17 at 06:14

Mureinik

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myCode.doSomething() is using println(), when try to get through getLog test case is not passed, If I use print method it's getting pass – Sasireka Ganesan Oct 24 '17 at 06:53
@SasirekaGanesan `println` adds a newline to the output. If you use it, you should assert against `"expected output\n"`. – Mureinik Oct 24 '17 at 07:34

Simulation of JUnit output for the given input

1 Answers1