Mockito when()...then() NullPointerException

Question

productsInDatabse is a hashMap, output is enum, scanCode is from class which is tested

   public static boolean isInDataBase(int code) {
        return productsInDatabse.containsKey(code);
    }

and I've got a test:

@Test
public void testScanCodeForCodeNotFound() {

    Database db = Mockito.mock(Database.class);
    when(db.isInDataBase(444)).thenReturn(false);
    output = scanner.scanCode("444");
    assertTrue(output == ProductProcessing.PRODUCT_NOT_FOUND);

}

But when()...then() returns with NPE. I saw examples when invoking was exactly like this. So my question is where is the bug, because I thought when()...then() works likes that.

Stacktrace:

Testcase: testScanCodeForCodeNotFound(iodevices.BarCodesScannerTest):   Caused an ERROR
null
java.lang.NullPointerException
    at database.Database.isInDataBase(Database.java:66)
    at iodevices.BarCodesScannerTest.testScanCodeForCodeNotFound(BarCodesScannerTest.java:50)
    at org.mockito.internal.runners.JUnit45AndHigherRunnerImpl.run(JUnit45AndHigherRunnerImpl.java:37)
    at org.mockito.runners.MockitoJUnitRunner.run(MockitoJUnitRunner.java:62)


Test iodevices.BarCodesScannerTest FAILED

You're calling your static method from a non-static context. Also, you can't mock static methods. — Alex, Dec 11 '15 at 12:08
Ok, so I can't mock static methods, that's sad... Is there workaround for this? Cause this method needs to be static, — meDarq, Dec 11 '15 at 12:09
You are even using this static method wrong. You call it like an instance method: `db.isInDataBase(...)`. So even this test code is misunderstanding! — Seelenvirtuose, Dec 11 '15 at 12:17

score 2 · Accepted Answer · edited May 23 '17 at 12:23

2

Remove the static from your isInDataBase() declaration.

See this if you can't remove the static: Mocking static methods with Mockito

edited May 23 '17 at 12:23

Community

1
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answered Dec 11 '15 at 12:08

Alex

5,364
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score 1 · Answer 2 · answered Dec 11 '15 at 12:11

1

You can't mock static methods with Mockito; you'll need PowerMock for that.

answered Dec 11 '15 at 12:11

jonk

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Mockito when()...then() NullPointerException

2 Answers2

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