"""
Test the invocation of the various Delegate static methods such as .combine, .remove and .removeAll.
"""

sig Handler(obj as Object)


class Program

	shared
	
		var _got = List<of Object>()

		def main
			h1 = Handler(ref .foo)
			h1('aoeu')
			.check('aoeu')
			
			h2 = Handler(ref .foo)
			h2('asdf')
			.check('aoeu', 'asdf')

			h = Delegate.combine(h1, h2) to Handler
			assert h.getInvocationList.length == 2
			assert h.getInvocationList[0] == h1
			assert h.getInvocationList[1] == h2
			_got.clear
			h(5)
			.check(5, 5)

			removed = Delegate.remove(h, Handler(ref .foo))
			assert removed.getInvocationList.length == 1
			assert Delegate.removeAll(h, h1) is nil

		def foo(obj as Object)
			_got.add(obj)

		def check(things as vari Object)
			assert things == _got