public Stream provideArguments()

in junit-jupiter-params/src/main/java/org/junit/jupiter/params/provider/EmptyArgumentsProvider.java [34:64]

• 27 lines of code
• 6 McCabe index (conditional complexity)

	public Stream<? extends Arguments> provideArguments(ExtensionContext context) {
		Method testMethod = context.getRequiredTestMethod();
		Class<?>[] parameterTypes = testMethod.getParameterTypes();

		Preconditions.condition(parameterTypes.length > 0, () -> String.format(
			"@EmptySource cannot provide an empty argument to method [%s]: the method does not declare any formal parameters.",
			testMethod.toGenericString()));

		Class<?> parameterType = parameterTypes[0];

		if (String.class.equals(parameterType)) {
			return Stream.of(arguments(""));
		}
		if (List.class.equals(parameterType)) {
			return Stream.of(arguments(Collections.emptyList()));
		}
		if (Set.class.equals(parameterType)) {
			return Stream.of(arguments(Collections.emptySet()));
		}
		if (Map.class.equals(parameterType)) {
			return Stream.of(arguments(Collections.emptyMap()));
		}
		if (parameterType.isArray()) {
			Object array = Array.newInstance(parameterType.getComponentType(), 0);
			return Stream.of(arguments(array));
		}
		// else
		throw new PreconditionViolationException(
			String.format("@EmptySource cannot provide an empty argument to method [%s]: [%s] is not a supported type.",
				testMethod.toGenericString(), parameterType.getName()));
	}