How to Junit test a try catch block in my code

Question

I have a class with couple of methods and each with a try catch block to look for any exceptions.

The code as follows:

public ResponseEntity get() {

    try {
        .....
    } catch (Exception e) {

        output = new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);
    }

    return output;
}

and I came up with a test case using Mokito to test the above scenario but confused how to enter into catch block of the above

@Test
public void testgetAllUsers_withoutexecp() {
    when(sMock.getAll()).thenReturn(someList);
    Assert.assertTrue(result.getStatusCode() ==  HttpStatus.OK );
}
@Test(expected=NullPointerException.class)
public void testgetAllUsers_execp() {
    when(sMock.getAll()).thenReturn(null);
    Assert.assertFalse(result.getStatusCode() ==  HttpStatus.OK );

}

I tried to raise a NullPointerException but still the catch block is left out in codecoverage (by which I assume it is not been tested). please help me to write a Junit test case for this to enter exception. I am very new to all these topics.

score 3 · Accepted Answer · answered May 22 '18 at 01:45

3

You can raise exception using thenThrow clause of Mockito:

when(serviceMock.getAllUser()).thenThrow(new NullPointerException("Error occurred"));

and then assert like this:

Assert.assertTrue(result.getStatusCode() ==  HttpStatus.INTERNAL_SERVER_ERROR);

answered May 22 '18 at 01:45

Shanu Gupta

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score 0 · Answer 2 · answered May 22 '18 at 01:47

0

Expecting NullPointerException makes no sense. This will never happen, because you catch exceptions.

Instead, test for AppConstants.ERROR_MESSAGE9 and HttpStatus.INTERNAL_SERVER_ERROR

answered May 22 '18 at 01:47

mentallurg

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How to Junit test a try catch block in my code

2 Answers2

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