Remove asserts the types already cover

The nil check burn down added guards which turned out redundant once
the surrounding annotations landed. `_has_handlers` is set to true when
the first handler registers, so it is a boolean rather than the literal
false it was inferred as.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

exp_gui/module/control.lua

@@ -116,7 +116,8 @@ end
 --- @param player LuaPlayer
 --- @return LuaGuiElement
 function Gui.get_top_element(define, player)
-    return (assert(assert(player_elements[player.index]).top[define.name], "Element is not on the top flow"))
+    local value = assert(assert(player_elements[player.index]).top[define.name], "Element is not on the top flow")
+    return value
 end
 
 --- Register a element define to be drawn to the left flow on join
@@ -124,7 +125,8 @@ end
 --- @param player LuaPlayer
 --- @return LuaGuiElement
 function Gui.get_left_element(define, player)
-    return (assert(assert(player_elements[player.index]).left[define.name], "Element is not on the left flow"))
+    local value = assert(assert(player_elements[player.index]).left[define.name], "Element is not on the left flow")
+    return value
 end
 
 --- Register a element define to be drawn to the relative flow on join
@@ -132,7 +134,8 @@ end
 --- @param player LuaPlayer
 --- @return LuaGuiElement
 function Gui.get_relative_element(define, player)
-    return (assert(assert(player_elements[player.index]).relative[define.name], "Element is not on the relative flow"))
+    local value = assert(assert(player_elements[player.index]).relative[define.name], "Element is not on the relative flow")
+    return value
 end
 
 --- Ensure all the correct elements are visible and exist

exp_gui/module/elements.lua

@@ -165,7 +165,7 @@ Elements.container = Gui.define("container")
 --- @param container LuaGuiElement
 --- @return LuaGuiElement
 function Elements.container.get_root_element(container)
-    return container.parent
+    return assert(container.parent)
 end
 
 --- A frame within a container
@@ -319,14 +319,15 @@ Elements.screen_frame = Gui.define("screen_frame")
 --- @param screen_frame LuaGuiElement
 --- @return LuaGuiElement
 function Elements.screen_frame.get_button_flow(screen_frame)
-    return (assert(Elements.screen_frame.data[screen_frame.parent], "Screen frame has no button flow"))
+    local value = assert(Elements.screen_frame.data[assert(screen_frame.parent)], "Screen frame has no button flow")
+    return value
 end
 
 --- Get the root element of a screen frame
 --- @param screen_frame LuaGuiElement
 --- @return LuaGuiElement
 function Elements.screen_frame.get_root_element(screen_frame)
-    return screen_frame.parent
+    return assert(screen_frame.parent)
 end
 
 return Elements

exp_gui/module/prototype.lua

@@ -43,6 +43,8 @@ ExpElement.events = {}
 --- @field _force_data ExpElement.PostDrawCallback?
 --- @field _global_data ExpElement.PostDrawCallback?
 --- @field _events table<defines.events, ExpElement.EventHandler<EventData>[]>
+--- @field _has_handlers boolean
+--- @field _track_elements boolean
 --- @overload fun(parent: LuaGuiElement, ...: any): LuaGuiElement
 ExpElement._prototype = {
     _track_elements = false,
@@ -166,7 +168,8 @@ end
 --- @param name string
 --- @return ExpElement
 function ExpElement.get(name)
-    return (assert(ExpElement._elements[name], "ExpElement is not defined: " .. tostring(name)))
+    local value = assert(ExpElement._elements[name], "ExpElement is not defined: " .. tostring(name))
+    return value
 end
 
 --- Create a new instance of this element definition