Java unit testing with parameter

Question

In C#, it is possible to specify parameters for the same unit test method. Example:

[DataTestMethod]
[DataRow(12,3,4)]
[DataRow(12,2,6)]
public void DivideTest(int n, int d, int q)
{
   Assert.AreEqual( q, n / d );
}

Is it possible to do the same in Java? I have read Parametrized runner but this solution is not as easy to use.

Have you had a look at [parameterized tests](https://blog.codefx.org/libraries/junit-5-parameterized-tests/) in [JUnit 5](http://junit.org/junit5/)? — beatngu13, Jul 01 '17 at 20:39
This is not a Java feature but a framework feature. I particularly like the way that Spock handles it, but both JUnit and TestNG have support, too. — chrylis -cautiouslyoptimistic-, Jul 01 '17 at 20:59

score 4 · Accepted Answer · answered Jul 01 '17 at 20:46

With JUnit 5, parameterized tests are really more straight and natural to use as with JUnit 4.

In your case, to provide multiple parameters as input, you could use the @CsvSource annotation.

Here are the required dependencies (maven declaration way) :

<dependency>
    <groupId>org.junit.jupiter</groupId>
    <artifactId>junit-jupiter-engine</artifactId>
    <version>5.0.0-M4</version>
    <scope>test</scope>
</dependency>

<dependency>
    <groupId>org.junit.jupiter</groupId>
    <artifactId>junit-jupiter-params</artifactId>
    <version>5.0.0-M4</version>
    <scope>test</scope>
</dependency>

And here is a sample code (with required imports) :

import org.junit.Assert;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.CsvSource;

public class YourTestClass{

    @ParameterizedTest
    @CsvSource({ "12,3,4", "12,2,6" })
    public void divideTest(int n, int d, int q) {
       Assert.assertEquals(q, n / d);
    }

}

score 3 · Answer 2 · answered Jul 01 '17 at 20:58

The Spock Framewok offers Data Driven Testing for Java and Groovy.

The Tests are (unfortunately?) written in Groovy:

class MathSpec extends Specification {
  def "maximum of two numbers"() {
    expect:
    Math.max(a, b) == c

    where:
    a | b || c
    1 | 3 || 3
    7 | 4 || 7
    0 | 0 || 0
  }
}

score 1 · Answer 3 · answered Jul 01 '17 at 20:35

1

You cannot achieve this so simple with JUnit out of the box, but you can use 3rd party JUnitParams:

@RunWith(JUnitParamsRunner.class)
public class PersonTest {

  @Test
  @Parameters({"17, false", 
               "22, true" })
  public void personIsAdult(int age, boolean valid) throws Exception {
    assertThat(new Person(age).isAdult(), is(valid));
  }

  @Test
  public void lookNoParams() {
    etc
  }
}

answered Jul 01 '17 at 20:35

Ivan Pronin

1,768
16
14

Thanks Ivan. Much better. Since Java8, annotations could be repeatable. Do you know if the same solution exists by repeating @Parameters? – OlivierTerrien Jul 01 '17 at 20:37
You mean, will it work for several annotated methods? Yes, it will. – Ivan Pronin Jul 01 '17 at 20:41
@Ivan Pronin +1 as nice alternative before Junit 5. – davidxxx Jul 01 '17 at 20:54

score 0 · Answer 4 · answered Jul 01 '17 at 20:31

0

yes, eg. JUnit has parameterized tests

https://github.com/junit-team/junit4/wiki/parameterized-tests

The only drawback is that all test methods in the class will be executed for each parameter (row).

answered Jul 01 '17 at 20:31

Timothy Truckle

15,071
2
27
51

Thanks Timothy, but as I said, I don't like this solution. The reason is parameters and testing methods are too distinct. That is why I think it is not as easy to use than C# solution. – OlivierTerrien Jul 01 '17 at 20:33

Java unit testing with parameter

4 Answers4