Testing a Condtional Based on Enum

Question

Should I test every condition in unit test when the conditional is based on a method of an enum?

I mean if I have an enum with a lot of values, the unit test gets too big to reach all possible conditions.

Example:

public enum AnEnum {
   A(true), B(false), C(false), D(true);

   AnEnum(boolean isError) {
       this.isError = isError
   }
}

public class TestEnum {
    public String method(AnEnum anEnum) {
         if( anEnum.isError() ) {
              return "An Error";
         }
         return "Not An Error";
    }
}

Possibly of interest [how to test enum types](http://stackoverflow.com/questions/1079700/how-to-test-enum-types). Also [data-driven-testing](https://spockframework.github.io/spock/docs/1.0/data_driven_testing.html) may be helpful, and not only for your enum but for cases which require it. — Morfic, Aug 25 '16 at 18:36
What is the point of testing getters and setters? Are you testing Java? Limit your test to things with actual logic in it. See [Should unit tests be written for getter and setters?](http://stackoverflow.com/q/6197370/5221149) — Andreas, Aug 25 '16 at 18:45
This is not about to test setters and getters. It is about to test all possible combination in your code. Should we test all combinations or should we test just 2 combinations ( in the example your can have 100% code coverage with only 2 combinations while your code can have a lot more combinations ) — Marcelo Paiva Fontes, Sep 01 '16 at 16:37

score 1 · Accepted Answer · answered Aug 25 '16 at 18:51

1

You could be using ParametrizedTests, like:

@DataProvider
public static Object[][] provideEnumasAndExpectedErrorResult() {
  return new Object[][] {
    { AnEnum.A, true },
    { AnEnum.B, false }
  };
}

@Test
@UseDataProvider( "provideEnumasAndExpectedErrorResult" )
public void testEnumErrors( AnEnum enumConstant, boolean expectedResult expectedResult ) {
  assertThat( enumConstant.isError(), is(expectedResult));

That allows you to write down all your enums and the expected results in a (somehow) cleaner way.

answered Aug 25 '16 at 18:51

GhostCat

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I apologize if you already knew, but depending on your licenses restrictions, you could also use these 2 extensions which make thinks cleaner and more elegant: [zohhak](https://github.com/piotrturski/zohhak) (LGPL 3.0) & [JUnitParams](https://github.com/Pragmatists/JUnitParams) (Apache 2.0) – Morfic Aug 25 '16 at 19:21

score 0 · Answer 2 · answered Aug 27 '16 at 20:45

Data-driven tests are great with Spock:

class AnEnumSpec extends Specification {

    def "has correct error status"() {
        expect:
        result == anEnum.isError

        where:
        anEnum   | result
        AnEnum.A | true
        AnEnum.B | false
        AnEnum.C | false
        AnEnum.D | true
    }
}

Testing a Condtional Based on Enum

2 Answers2