@CartesianProductTest extension

Overview

Provide a similar, but complete and fleshed-out, extension that provides a @CartesianProductTest annotation implemention.

Usage outline

@CartesianProductTest({"0", "1"})
void threeBits(String a, String b, String c) {
	int value = Integer.parseUnsignedInt(a + b + c, 2);
	assertTrue((0b000 <= value) && (value <= 0b111));
}

@CartesianProductTest
@DisplayName("S ⨯ T ⨯ U")
void nFold(String string, Class<?> type, TimeUnit unit, TestInfo info) {
	assertTrue(string.endsWith("a"));
	assertTrue(type.isInterface());
	assertTrue(unit.name().endsWith("S"));
	assertTrue(info.getTags().isEmpty());
}

static CartesianProductTest.Sets nFold() {
	return new CartesianProductTest.Sets()
			.add("Alpha", "Omega")
			.add(Runnable.class, Comparable.class, TestInfo.class)
			.add(TimeUnit.DAYS, TimeUnit.HOURS);
}

Implementation idea

https://github.com/junit-team/junit5-samples/tree/master/junit5-jupiter-extensions/src/main/java/com/example/cartesian

Todos

• Copy sources from junit5-jupiter-extensions and adopt to pioneers’ (package) structure.
• Write unit and integration tests for the @CartesianProductTest and its provider.
• Support more basic types in the annotation, in addition to String?
• Document usage and limitations

[sormuras]

Ideally the @CartesianProductTest would be able to reuse any existing argument source, including the @RangeSource described in #123. For example:

@CartesianProductTest
@EnumSource(TimeUnit.class)
@ValueSource(ints = {1, 2, 3})
@RangeSource(2, 10, 2)
void test(TimeUnit unit, int a, int b) {...}

[matthieu-vergne]

I like the idea of tagging the parameters. If an issue is open on that topic, please share its link here.