JUnit 5 @ParamterizedTest {arguments} vs {argumentsWithNames} placeholders

I'm using JUnit 5.7.0, IntellijIDEA 2021.1.2 CE, MacOS Catalina 10.15. and don't understand the difference between ParameterizedTest.ARGUMENTS_PLACEHOLDER and ParameterizedTest.ARGUMENTS_WITH_NAMES_PLACEHOLDER.

According to the javadoc ARGUMENTS_WITH_NAMES_PLACEHOLDER deals with named arguments whereas ARGUMENTS_PLACEHOLDER with just arguments. The test result in IDEA for both tests looks the same:

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

@ParameterizedTest(name = ARGUMENTS_WITH_NAMES_PLACEHOLDER)
@CsvSource({"apple, 1", "banana, 2", "'lemon, lime', 3" })
void testWithArguments(String fruit, int rank) {
}

@ParameterizedTest(name = ARGUMENTS_PLACEHOLDER)
@CsvSource({"apple, 1", "banana, 2", "'lemon, lime', 3" })
void testWithNamedArguments(String fruit, int rank) {
}

Can anyone provide an example where these two placeholders behave differently?

Solution 1:

If you use @ParameterizedTest(name = ARGUMENTS_WITH_NAMES_PLACEHOLDER) you'll get output result with parameterName + "=" + paraveterValue.

But if you use @ParameterizedTest(name = ARGUMENTS_PLACEHOLDER) you'll get only paraveterValue

Also, you can see that in javadoc:

Placeholder for the complete, comma-separated named arguments list of the current invocation of a @ParameterizedTest method: {argumentsWithNames}

@API(status = EXPERIMENTAL, since = "5.6")
String ARGUMENTS_WITH_NAMES_PLACEHOLDER = "{argumentsWithNames}";

Default display name pattern for the current invocation of a @ParameterizedTest method: "[{index}] {argumentsWithNames}"
Note that the default pattern does not include the display name of the @ParameterizedTest method.

@API(status = EXPERIMENTAL, since = "5.3")
String DEFAULT_DISPLAY_NAME = "[" + INDEX_PLACEHOLDER + "] " + ARGUMENTS_WITH_NAMES_PLACEHOLDER;

I tried to run your code like that:

@ParameterizedTest(name = ARGUMENTS_WITH_NAMES_PLACEHOLDER)
@CsvSource({"apple, 1", "banana, 2", "'lemon, lime', 3" })
void testWithNamedArguments(String fruit, int rank) {
}

and I got the correct result:

I use jupiter 5.6.3, the feature ARGUMENTS_WITH_NAMES_PLACEHOLDER appeared since 5.6 version.