Fix GD.yield return value (#14)

CHANGELOG.md

@@ -13,6 +13,10 @@
   with the passed name. Properties are considered available if they are found in
   the result of `ClassDB:class_get_property_list`.
 
+### Fixed
+
+- Return values passed to `lps_coroutine:resume(...)` when calling `GD.yield()`.
+
 ### Changed
 
 - **BREAKING CHANGE**: `Array` and `Pool*Array`'s `__index` and `__newindex`

src/late_globals.lua

@@ -129,7 +129,7 @@ function GD.yield(object, signal_name)
 	if object and signal_name then
 		object:connect(signal_name, co_obj, "resume", Array(), Object.CONNECT_ONESHOT)
 	end
-	coroutine_yield(co_obj)
+	return coroutine_yield(co_obj)
 end
 
 local Engine = api.godot_global_get_singleton("Engine")

src/test/coroutines.lua

@@ -0,0 +1,17 @@
+local lu = require "luaunit"
+
+local Test = {}
+
+function Test:return_yield()
+	return GD.yield()
+end
+
+function Test:test_yield_results()
+	local coro = self:call('return_yield')
+	lu.assert_nil(coro:resume())
+
+	local coro = self:call('return_yield')
+	lu.assert_equals(coro:resume(42), 42)
+end
+
+return Test