CartesianArgumentsProvider is not intuitive to implement

[filiphr]

If I am a library developer that would like to implement a CartesianArgumentsProvider I would have to make my class be stateful and I would have to make my implementation implement ArgumentsProvider (even if I don't want to do that).

The current API looks like this:

public interface CartesianArgumentsProvider extends ArgumentsProvider {

    void accept(Parameter parameter);

}

This means that if my implementation is both for @CartesianTest and @ParametrizedTest then I have to have a state in it and implement AnnotationConsumer.

In addition to that there is no way for me to use a CartesianArgumentsProvider without creating an annotation. For example for @ParametrizedTest I can do the following:

class MyTest {

    @ParametrizedTest
    @ArgumentsSource(MyArgumentsProvider.class)
    void myTest(String argument);

}

However, I cannot do something like

class MyTest {

    @CartesianTest
    void myTest(@ArgumentsSource(MyArgumentsProvider.class) String argument);

}

Because @ArgumentsSource is from JUnit jupiter and its target is only ANNOTATION_TYPE and METHDO.

[filiphr]

While working on some tests for PR #519 which is linked to this issue. I came to something which confuses me.

It is

junit-pioneer/src/main/java/org/junitpioneer/jupiter/cartesian/CartesianTestExtension.java

Lines 75 to 77 in bd6d994

	if (!methodSources.isEmpty() && !parameterSources.isEmpty())
	throw new ExtensionConfigurationException(
	"Providing both method-level and parameter-level argument sources for @CartesianTest is not supported.");

That error makes it like method level argument sources are allowed. However, if we do that it is not working. That can be seen in

junit-pioneer/src/main/java/org/junitpioneer/jupiter/cartesian/CartesianTestExtension.java

Line 69 in bd6d994

return getSetsFromArgumentsSources(parameterArgumentsSources, context);

. Basically only the parameterArgumentsSources are passed to the getSetsFromArgumentsSource. What is the goal here?

[Michael1993]

There are currently no method-level argument sources for @CartesianTest. In another PR, I hope to add @FactorySource (and perhaps @SingleSource).

[filiphr]

Thanks for the clarification @Michael1993. My changes in PR #519 could actually help with that as well. You could pass each parameter to the method cartesian argument source. That way your custom implementation also has access to the parameter.

[Bukama]

Thank you for opening the requested issue. It's more clearer for me now!