@EnumSource for enum values in JUnit - Build an Automation Script

Verify method behavior for all enum values using @EnumSource

Preconditions (2)

Step 1: Create a parameterized test using JUnit 5

Step 2: Use @EnumSource to supply all Color enum values to the test method

Step 3: For each enum value, call isPrimaryColor with the enum value

Step 4: Verify the returned boolean matches expected: true for RED and BLUE, false for GREEN

✅ Expected Result: The test passes for all enum values, correctly asserting the method behavior

Automation Requirements - JUnit 5

Assertions Needed:

AssertTrue or AssertFalse depending on enum value

Best Practices:

Use @ParameterizedTest with @EnumSource for enum values

Use descriptive test method names

Keep test logic simple and clear

Automated Solution

JUnit

import static org.junit.jupiter.api.Assertions.*;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.EnumSource;

public class ColorTest {

    enum Color {
        RED, GREEN, BLUE
    }

    boolean isPrimaryColor(Color color) {
        return color == Color.RED || color == Color.BLUE;
    }

    @ParameterizedTest(name = "Test isPrimaryColor with {0}")
    @EnumSource(Color.class)
    void testIsPrimaryColor(Color color) {
        boolean expected = (color == Color.RED || color == Color.BLUE);
        assertEquals(expected, isPrimaryColor(color));
    }
}

This test class defines an enum Color with three values.

The method isPrimaryColor returns true only for RED and BLUE.

The test method testIsPrimaryColor is a parameterized test using @EnumSource(Color.class) to run once for each enum value.

Inside the test, it calculates the expected result and asserts that the method returns the correct boolean.

This approach ensures all enum values are tested automatically without writing separate tests for each.

Common Mistakes - 3 Pitfalls

Not using @EnumSource and manually listing enum values

Using incorrect assertion methods like asserttrue without condition

Not importing necessary JUnit 5 packages

Bonus Challenge

Now add a test that uses @EnumSource with names to test only RED and BLUE enum values

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