Argument conversion in JUnit - Test Execution Trace

Test Overview

This test checks if a JUnit 5 parameterized test correctly converts a string argument to an integer and verifies the calculation result.

Test Code - JUnit 5

JUnit

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

public class ArgumentConversionTest {

    @ParameterizedTest
    @ValueSource(strings = {"2", "3", "5"})
    void testSquareConversion(String input) {
        int number = Integer.parseInt(input);
        int square = number * number;
        assertEquals(square, number * number, "Square calculation should be correct");
    }
}

Execution Trace - 8 Steps

Step	Action	System State	Assertion	Result
1	Test runner starts and identifies the parameterized test with string inputs	JUnit test environment initialized, test class loaded	-	PASS
2	Test executes with input argument "2" as String	Test method invoked with input = "2"	Integer.parseInt converts "2" to 2 correctly	PASS
3	Calculate square of 2 and assert result equals 4	square = 4	assertEquals(4, 4) passes	PASS
4	Test executes with input argument "3" as String	Test method invoked with input = "3"	Integer.parseInt converts "3" to 3 correctly	PASS
5	Calculate square of 3 and assert result equals 9	square = 9	assertEquals(9, 9) passes	PASS
6	Test executes with input argument "5" as String	Test method invoked with input = "5"	Integer.parseInt converts "5" to 5 correctly	PASS
7	Calculate square of 5 and assert result equals 25	square = 25	assertEquals(25, 25) passes	PASS
8	All parameterized test cases completed successfully	Test run finished	-	PASS

Failure Scenario

Failing Condition: Input string cannot be converted to integer (e.g., non-numeric string)

Execution Trace Quiz - 3 Questions

What does the test convert the input string argument into?

A A boolean

B A double

C An integer

D A character

Key Result

Always validate or handle argument conversions in parameterized tests to avoid runtime exceptions and ensure test reliability.