From 706eded24faff76361fb94b6e6f00d96fd2f12da Mon Sep 17 00:00:00 2001
From: EncodedVenom <32179912+EncodedVenom@users.noreply.github.com>
Date: Mon, 8 Jul 2024 09:51:34 -0400
Subject: [PATCH] Add null query unit tests (#69)

* Add null query unit test

* Add unit test

* Update unit tests

* Remove __iter from already tested case
---
 tests/world.luau | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/tests/world.luau b/tests/world.luau
index 178650a..bb33fa7 100644
--- a/tests/world.luau
+++ b/tests/world.luau
@@ -471,6 +471,47 @@ TEST("world", function()
 		CHECK(world:get(e, B) == false)
 		CHECK(world:get(e, C) == "hello world")
 	end
+
+	do CASE "should not iterate when nothing matches query"
+		local world = jecs.World.new()
+		local A = world:component()
+		local B = world:component()
+
+		local e1 = world:entity()
+		world:add(e1, A)
+
+		local count = 0
+		for id in world:query(B) do
+			count += 1
+		end
+
+		CHECK(count == 0)
+	end
+
+	do CASE "should return nothing for empty iteration"
+		local world = jecs.World.new()
+		local A = world:component()
+		local B = world:component()
+
+		local e1 = world:entity()
+		world:add(e1, A)
+
+		local query = world:query(B)
+		CHECK(query.next() == nil)
+		CHECK(query.replace() == nil)
+	end
+
+	do CASE "should properly handle query:without for empty iteration"
+		local world = jecs.World.new()
+		local A = world:component()
+		local B = world:component()
+
+		local e1 = world:entity()
+		world:add(e1, A)
+
+		local query = world:query(B)
+		CHECK(query == query:without())
+	end
 end)
 
 FINISH()