ReplaceCamelCaseAndUnderscoreAndNumber

The aim is to simplify unit test display names for method names combining CamelCase, underscore and numbers. Instead of using the method annotation org.junit.jupiter.api.DisplayName, we can just use the class annotation org.junit.jupiter.api.DisplayNameGeneration and only use the method annotation if needed.

Applying @DisplayNameGeneration(ReplaceCamelCaseAndUnderscoreAndNumber.class) to the test class will provide human-readable descriptions for test methods not annotated with @DisplayName.

3 key rules:

• Each uppercase letter is turned into its lowercase value prepended by a space.

• Each underscore is turned into a space. Words bounded by underscores or just starting with underscore are not transformed. Usually, these words represent classes or variables.

• Each number is prepended by a space.

@DisplayNameGeneration(ReplaceCamelCaseAndUnderscoreAndNumber.class)

Usage Example:

@DisplayNameGeneration(ReplaceCamelCaseAndUnderscoreAndNumber.class)
class ReplaceCamelCaseAndUnderscoreAndNumberStyleTest {

    @Test
    void shouldReturnErrorWhen_maxResults_IsNegative() {
    }

    @ParameterizedTest
    @ValueSource(strings = { "", "  " })
    void shouldCreateLimitWithRange(String input) {
    }

    @ParameterizedTest
    @ValueSource(ints = { 5, 23 })
    void shouldReturn5Errors(int input) {
    }

    @Test
    void shouldReturn5errors() {
    }

    @Test
    void shouldReturn23Errors() {
    }

    @Test
    void shouldReturnTheValueOf_maxResults() {
    }

    @ParameterizedTest
    @ValueSource(strings = { "", "  " })
    void shouldReturnTheNumberOfErrorsAs_numberOfErrors_InferiorOrEqualTo5(String input) {
    }

    @Test
    void shouldReturnTheNumberOfErrorsAs_numberOfErrors_InferiorOrEqualTo15() {
    }

    @DisplayName("@DisplayName prevails")
    @Test
    void testDisplayNamePrevails() {
    }

}

Method 1

Generated display name: Should return error when maxResults is negative

@Test
void shouldReturnErrorWhen_maxResults_IsNegative() {
}

Method 2

Generated display name: Should create limit with range (String)

@ParameterizedTest
@ValueSource(strings = { "", "  " })
void shouldCreateLimitWithRange(String input) {
}

Method 3

Generated display name: Should return 5 errors (int)

@ParameterizedTest
@ValueSource(ints = { 5, 23 })
void shouldReturn5Errors(int input) {
}

Method 4

Generated display name: Should return 5 errors

@Test
void shouldReturn5errors() {
}

Method 5

Generated display name: Should return 23 errors

@Test
void shouldReturn23Errors() {
}

Method 6

Generated display name: Should return the value of maxResults

@Test
void shouldReturnTheValueOf_maxResults() {
}

Method 7

Generated display name: Should return the number of errors as numberOfErrors inferior or equal to 5 (String)

@ParameterizedTest
@ValueSource(strings = { "", "  " })
void shouldReturnTheNumberOfErrorsAs_numberOfErrors_InferiorOrEqualTo5(String input) {
}

Method 8

Generated display name: Should return the number of errors as numberOfErrors inferior or equal to 15

@Test
void shouldReturnTheNumberOfErrorsAs_numberOfErrors_InferiorOrEqualTo15() {
}

Method 9

Generated display name: @DisplayName prevails

@DisplayName("@DisplayName prevails")
@Test
void testDisplayNamePrevails() {
}