Create multiple parameter sets in one parameterized class (junit)

Question

Currently I have to create a parameterized test class for every method that I want to test with several different inputs. Is there a way to add this together in one file?

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Answer 1

With Junit Jupiter: https://www.petrikainulainen.net/programming/testing/junit-5-tutorial-writing-parameterized-tests/

import intf.ICalculator;

public class Calculator implements ICalculator {
    @Override
    public int plus(int a, int b) {return a + b; }

    @Override
    public int minuis(int a, int b) {return a - b;}

    @Override
    public int multy(int a, int b) {return a * b;}

    @Override  // check in junit byZero
    public int divide(int a, int b) {return a / b;}

}

Test class:

import static org.junit.Assert.assertEquals;

import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.CsvSource;

class CalculatorJupiter5Test {

    Calculator calculator = new Calculator();

    @DisplayName("Should calculate the correct sum")
    @ParameterizedTest(name = "{index} => a={0}, b={1}, sum={2}")
    @CsvSource({
            "5, 3, 8",
            "1, 3, 4",
            "6, 6, 12",
            "2, 3, 5"
    })
    void sum(int a, int b, int sum) {
        assertEquals(sum, calculator.plus(a, b) );
    }

    @DisplayName("Should calculate the correct multy")
    @ParameterizedTest(name = "{index} => a={0}, b={1}, multy={2}")
    @CsvSource({
        "5, 3, 15",
        "1, 3, 3",
        "6, 6, 36",
        "2, 3, 6"
    })
    void multy(int a, int b, int multy) {
        assertEquals(multy, calculator.multy(a, b) );
    }

    @DisplayName("Should calculate the correct divide")
    @ParameterizedTest(name = "{index} => a={0}, b={1}, divide={2}")
    @CsvSource({
        "5, 3, 1",
        "14, 3, 4",
        "6, 6, 1",
        "36, 2,  18"
    })
    void divide(int a, int b, int divide) {
        assertEquals(divide, calculator.divide(a, b) );
    }

   @DisplayName("Should calculate the correct divide by zero")
   @ParameterizedTest(name = "{index} => a={0}, b={1}, divide={2}")
   @CsvSource({
      "5, 0, 0",
   })
    void divideByZero(int a, int b, int divide) {
     assertThrows(ArithmeticException.class,
         () -> calculator.divide(a , b),
         () -> "divide by zero");
    }

    @DisplayName("Should calculate the correct minuis")
    @ParameterizedTest(name = "{index} => a={0}, b={1}, minuis={2}")
    @CsvSource({
        "5, 3, 2",
        "1, 3, -2",
        "6, 6, 0",
        "2, 3, -1"
    })
    void minuis(int a, int b, int minuis) {
        assertEquals(minuis, calculator.minuis(a, b) );
    }
}