Custom display names for parameters in JUnit - Test Execution Trace

Test Overview

This test uses JUnit to run a parameterized test with custom display names for each parameter set. It verifies that the sum of two numbers matches the expected result.

Test Code

JUnit

import static org.junit.jupiter.api.Assertions.assertEquals;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.CsvSource;

public class CalculatorTest {

    @ParameterizedTest(name = "Sum of {0} and {1} should be {2}")
    @CsvSource({
        "1, 2, 3",
        "4, 5, 9",
        "10, 20, 30"
    })
    void testSumWithCustomDisplayName(int a, int b, int expected) {
        assertEquals(expected, a + b);
    }
}

Execution Trace - 6 Steps

Step	Action	System State	Assertion	Result
1	Test runner starts and loads CalculatorTest class	JUnit test environment initialized	-	PASS
2	JUnit identifies parameterized test method testSumWithCustomDisplayName with 3 parameter sets	Test method ready to run with parameters (1,2,3), (4,5,9), (10,20,30)	-	PASS
3	JUnit runs testSumWithCustomDisplayName with parameters (1, 2, 3)	Test method executing with a=1, b=2, expected=3	assertEquals(3, 1 + 2)	PASS
4	JUnit runs testSumWithCustomDisplayName with parameters (4, 5, 9)	Test method executing with a=4, b=5, expected=9	assertEquals(9, 4 + 5)	PASS
5	JUnit runs testSumWithCustomDisplayName with parameters (10, 20, 30)	Test method executing with a=10, b=20, expected=30	assertEquals(30, 10 + 20)	PASS
6	Test runner completes all parameterized tests and reports results	All parameterized tests passed with custom display names shown in test report	-	PASS

Failure Scenario

Failing Condition: One of the parameterized test cases has an incorrect expected sum

Execution Trace Quiz - 3 Questions

What does the custom display name in the parameterized test show?

A The class name only

B The sum calculation details for each parameter set

C The default method name without parameters

D The test execution time

Key Result

Using custom display names for parameters helps make test reports clearer and easier to understand by showing exactly what each test case is checking.