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_commands/module/module_exports.lua

@@ -170,7 +170,8 @@ Commands.server = setmetatable({
 --- @param msg LocalisedString? An optional message to be included when a command completes (only has an effect in command callbacks)
 --- @return Commands.Status, LocalisedString # Should be returned directly without modification
 function Commands.status.success(msg)
-    return Commands.status.success, msg == nil and { "exp-commands.success" } or msg
+    if msg == nil then return Commands.status.success, { "exp-commands.success" } end
+    return Commands.status.success, msg
 end
 
 --- Used to signal an error has occurred in a command, data type parser, or permission authority
@@ -178,7 +179,8 @@ end
 --- @param msg LocalisedString? An optional error message to be included in the output, a generic message is used if not provided
 --- @return Commands.Status, LocalisedString # Should be returned directly without modification
 function Commands.status.error(msg)
-    return Commands.status.error, { "exp-commands.error", msg == nil and { "exp-commands.error-default" } or msg }
+    if msg == nil then msg = { "exp-commands.error-default" } end
+    return Commands.status.error, { "exp-commands.error", msg }
 end
 
 --- Used to signal the player is unauthorised to use a command, primarily used by permission authorities but can be used in a command callback
@@ -186,7 +188,8 @@ end
 --- @param msg LocalisedString? An optional error message to be included in the output, a generic message is used if not provided
 --- @return Commands.Status, LocalisedString # Should be returned directly without modification
 function Commands.status.unauthorised(msg)
-    return Commands.status.unauthorised, { "exp-commands.unauthorized", msg == nil and { "exp-commands.unauthorized-default" } or msg }
+    if msg == nil then msg = { "exp-commands.unauthorized-default" } end
+    return Commands.status.unauthorised, { "exp-commands.unauthorized", msg }
 end
 
 --- Used to signal the player provided invalid input to an command, primarily used by data type parsers but can be used in a command callback
@@ -194,15 +197,16 @@ end
 --- @param msg LocalisedString? An optional error message to be included in the output, a generic message is used if not provided
 --- @return Commands.Status, LocalisedString # Should be returned directly without modification
 function Commands.status.invalid_input(msg)
-    return Commands.status.invalid_input, msg == nil and { "exp-commands.invalid-input" } or msg
+    if msg == nil then return Commands.status.invalid_input, { "exp-commands.invalid-input" } end
+    return Commands.status.invalid_input, msg
 end
 
 --- Used to signal an internal error has occurred, this is reserved for internal use only
---- @param msg LocalisedString A message detailing the error which has occurred, will be logged and outputted
+--- @param msg LocalisedString? A message detailing the error which has occurred, will be logged and outputted
 --- @return Commands.Status, LocalisedString # Should be returned directly without modification
 --- @package
 function Commands.status.internal_error(msg)
-    return Commands.status.internal_error, { "exp-commands.internal-error", msg }
+    return Commands.status.internal_error, { "exp-commands.internal-error", msg or "" }
 end
 
 --- @type table<Commands.Status, string>

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

exp_legacy/module/expcore/external.lua

@@ -50,7 +50,8 @@ local servers = External.get_servers()
 ]]
 function External.get_servers()
     assert(ext, "No external data was found, use External.valid() to ensure external data exists.")
-    return (assert(ext.servers, "No server list was found, please ensure that the external service is running"))
+    local value = assert(ext.servers, "No server list was found, please ensure that the external service is running")
+    return value
 end
 
 --[[-- Gets a table of all the servers filtered by name, key is the server id, value is the server details
@@ -85,7 +86,8 @@ function External.get_current_server()
     assert(ext, "No external data was found, use External.valid() to ensure external data exists.")
     local servers = assert(ext.servers, "No server list was found, please ensure that the external service is running")
     local server_id = assert(ext.current, "No current id was found, please ensure that the external service is running")
-    return (assert(servers[server_id], "No details found for server with id: " .. tostring(server_id)))
+    local value = assert(servers[server_id], "No details found for server with id: " .. tostring(server_id))
+    return value
 end
 
 --[[-- Gets the details of the given server
@@ -99,7 +101,8 @@ local server = External.get_server_details('eu-01')
 function External.get_server_details(server_id)
     assert(ext, "No external data was found, use External.valid() to ensure external data exists.")
     local servers = assert(ext.servers, "No server list was found, please ensure that the external service is running")
-    return (assert(servers[server_id], "No details found for server with id: " .. tostring(server_id)))
+    local value = assert(servers[server_id], "No details found for server with id: " .. tostring(server_id))
+    return value
 end
 
 --[[-- Gets the status of the given server

exp_legacy/module/expcore/roles.lua

@@ -216,7 +216,7 @@ game.player.print(Roles.debug())
 function Roles.debug()
     local output = ""
     for index, role_name in ipairs(Roles.config.order) do
-        local role = assert(Roles.config.roles[role_name])
+        local role = Roles.config.roles[role_name]
         local color = (role.custom_color or Colours.white) --[[@as Color.struct]]
         local color_str = string.format("[color=%d, %d, %d]", color.r, color.g, color.b)
         output = output .. string.format("\n%s %s) %s[/color]", color_str, index, serpent.line(role))
@@ -369,14 +369,15 @@ local role = Roles.get_player_highest_role(game.player)
 --- @return Roles.Role
 function Roles.get_player_highest_role(player)
     local roles = Roles.get_player_roles(player)
-    local highest
+    local highest --- @type Roles.Role?
     for _, role in ipairs(roles) do
         if not highest or role.index < highest.index then
             highest = role
         end
     end
 
-    return (assert(highest, "Player has no roles"))
+    local value = assert(highest, "Player has no roles")
+    return value
 end
 
 --- Assignment.
@@ -415,7 +416,7 @@ function Roles.assign_player(player, roles, by_player_name, skip_checks, silent)
 
     -- If the player has a role that needs to defer the role changes, save the roles that need to be assigned later into a table
     if valid_player and Roles.player_has_flag(valid_player, "defer_role_changes") then
-        local assign_later = Roles.config.deferred_roles[assert(valid_player).name] or {}
+        local assign_later = Roles.config.deferred_roles[valid_player.name] or {}
         for _, role in ipairs(role_objects) do
             local role_change = assign_later[role.name]
             if role_change then
@@ -431,7 +432,7 @@ function Roles.assign_player(player, roles, by_player_name, skip_checks, silent)
             end
         end
 
-        Roles.config.deferred_roles[assert(valid_player).name] = assign_later
+        Roles.config.deferred_roles[valid_player.name] = assign_later
         return
     end
 
@@ -477,8 +478,8 @@ function Roles.unassign_player(player, roles, by_player_name, skip_checks, silen
 
     -- If the player has a role that needs to defer the role changes, save the roles that need to be unassigned later into a table
     local defer_changes = Roles.player_has_flag(player, "defer_role_changes")
-    if defer_changes then
+    if defer_changes and valid_player then
-        local assign_later = Roles.config.deferred_roles[assert(valid_player).name] or {}
+        local assign_later = Roles.config.deferred_roles[valid_player.name] or {}
         for _, role in ipairs(role_objects) do
             local role_change = assign_later[role.name]
             if role_change then
@@ -494,7 +495,7 @@ function Roles.unassign_player(player, roles, by_player_name, skip_checks, silen
             end
         end
 
-        Roles.config.deferred_roles[assert(valid_player).name] = assign_later
+        Roles.config.deferred_roles[valid_player.name] = assign_later
     end
 
     -- Remove the player from roles
@@ -674,7 +675,7 @@ function Roles.define_role_order(order)
 
     -- Re-links roles to they parents as this is called at the end of the config
     for index, role_name in pairs(Roles.config.order) do
-        local role = assert(Roles.config.roles[role_name])
+        local role = Roles.config.roles[role_name]
         if not role then
             error("Role with name " .. role_name .. " has not beed defined, either define it or remove it from the order list.", 2)
         end

exp_legacy/module/modules/control/vlayer.lua

@@ -291,7 +291,7 @@ function vlayer.remove_item(item_name, count)
 
     if not config.unlimited_surface_area and item_properties.required_area and item_properties.required_area > 0 then
         -- Remove from the unallocated storage first
-        remove_unallocated = math.min(count, assert(vlayer_data.storage.unallocated[item_name]))
+        remove_unallocated = math.min(count, vlayer_data.storage.unallocated[item_name])
 
         if remove_unallocated > 0 then
             vlayer_data.storage.items[item_name] = vlayer_data.storage.items[item_name] - count

exp_legacy/module/modules/gui/vlayer.lua

@@ -381,14 +381,13 @@ local vlayer_gui_control_see = Gui.define("vlayer_gui_control_see")
     }:style{
         width = 200,
     }:on_click(function(def, player, element, event)
-        local target = assert(assert(element.parent)[vlayer_gui_control_type.name]).selected_index
+        local target = assert(element.parent)[vlayer_gui_control_type.name].selected_index
-        local n = assert(assert(element.parent)[vlayer_gui_control_list.name]).selected_index
+        local n = assert(element.parent)[vlayer_gui_control_list.name].selected_index
         
         if target and vlayer_control_type_list[target] and n > 0 then
             local i = vlayer.get_interfaces()
             local entity = i[vlayer_control_type_list[target]][n]
             if entity and entity.valid then
-                local player = Gui.get_player(event)
                 player.set_controller{ type = defines.controllers.remote, position = entity.position, surface = entity.surface }
                 player.print{ "vlayer.result-interface-location", { "vlayer.control-type-" .. vlayer_control_type_list[target]:gsub("_", "-") }, pos_to_gps_string(entity.position, entity.surface.name) }
             end
@@ -425,8 +424,8 @@ local vlayer_gui_control_remove = Gui.define("vlayer_gui_control_remove")
     }:style{
         width = 200,
     }:on_click(function(def, player, element)
-        local target = assert(assert(element.parent)[vlayer_gui_control_type.name]).selected_index
+        local target = assert(element.parent)[vlayer_gui_control_type.name].selected_index
-        local n = assert(assert(element.parent)[vlayer_gui_control_list.name]).selected_index
+        local n = assert(element.parent)[vlayer_gui_control_list.name].selected_index
 
         if target and vlayer_control_type_list[target] and n > 0 then
             local i = vlayer.get_interfaces()

exp_legacy/module/modules/gui/warp-list.lua

@@ -294,10 +294,10 @@ local confirm_edit_button = Gui.define("confirm_edit_button")
         local parent = assert(element.parent)
         local grandparent = assert(parent.parent)
         local warp_id = parent.caption --[[@as string]]
-        local name_flow = assert(grandparent["name-" .. warp_id])
+        local name_flow = grandparent["name-" .. warp_id]
-        local icon_flow = assert(grandparent["icon-" .. warp_id])
+        local icon_flow = grandparent["icon-" .. warp_id]
-        local warp_name = assert(name_flow[warp_textfield.name]).text
+        local warp_name = name_flow[warp_textfield.name].text
-        local warp_icon = assert(icon_flow[warp_icon_editing.name]).elem_value --[[@as SignalID]]
+        local warp_icon = icon_flow[warp_icon_editing.name].elem_value --[[@as SignalID]]
         if warp_icon.type == nil then warp_icon.type = "item" end
         Warps.set_editing(warp_id, player.name)
         Warps.update_warp(warp_id, warp_name, warp_icon, player.name)

exp_scenario/module/commands/connect.lua

@@ -41,7 +41,7 @@ local function get_server_id(server)
         elseif status == "Offline" then
             return false, { "exp-commands_connect.offline", server_details.name }
         end
-        return true, server_id
+        return true, server_id --[[@as string]]
     elseif server_count_before > 0 then
         return false, { "exp-commands_connect.wrong-version", concat(server_names_before, ", ") }
     else

exp_scenario/module/commands/reports.lua

@@ -43,11 +43,11 @@ Commands.new("create-report", { "exp-commands_reports.description-create" })
         if Reports.report_player(other_player, player.name, reason) then
             local user_message = { "exp-commands_reports.response", other_player_name, reason }
             local admin_message = { "exp-commands_reports.response-admin", other_player_name, player_name, reason }
-            for _, player in ipairs(game.connected_players) do
+            for _, connected_player in ipairs(game.connected_players) do
-                if player.admin then
+                if connected_player.admin then
-                    player.print(admin_message)
+                    connected_player.print(admin_message)
                 else
-                    player.print(user_message)
+                    connected_player.print(user_message)
                 end
             end
         else

exp_scenario/module/commands/search.lua

@@ -91,7 +91,7 @@ local function sort_results(results, func)
         end
     end
 
-    return sorted
+    return sorted --[[@as SearchResult[] ]]
 end
 
 local display_players_time_format = ExpUtil.format_time_factory_locale{ format = "short", hours = true, minutes = true }

exp_scenario/module/control/discord_alerts.lua

@@ -32,7 +32,7 @@ end
 
 --- Get the player name from an event
 --- @param event { player_index: uint, by_player_name: string? }
---- @return string, string
+--- @return string, string?
 local function get_player_name(event)
     local player = game.players[event.player_index]
     return player.name, event.by_player_name

exp_scenario/module/gui/player_list.lua

@@ -102,11 +102,11 @@ Elements.reason_confirm = Gui.define("player_list/reason_confirm")
         local action_name = Elements.container.get_selected_action(player)
         local button_data = action_name and config.buttons[action_name]
         if button_data and button_data.reason_callback then
-            local reason = assert(assert(element.parent).entry).text --[[@as string?]]
+            local reason = assert(element.parent).entry.text --[[@as string?]]
             if reason == nil or not reason:find("%S") then reason = "no reason given" end
             button_data.reason_callback(player, reason)
         end
-        assert(assert(element.parent).entry).text = ""
+        assert(element.parent).entry.text = ""
         Elements.container.set_selected_player(player, nil)
         Elements.player_table.refresh_player(player)
     end) --[[@as any]]

exp_scenario/module/gui/quick_actions.lua

@@ -43,7 +43,7 @@ local function new_quick_action(command, on_click)
         :style{
             width = 160,
         }
-        :on_click(on_click or function(def, player, element, event)
+        :on_click(on_click or function(_def, player, _element, _event)
             command(player)
         end)
 

exp_scenario/module/gui/research_milestones.lua

@@ -270,10 +270,9 @@ Elements.container = Gui.define("research_milestones/container")
         local milestone_table = Elements.milestone_table(container)
         Elements.clock_label(header)
 
-        local force = Gui.get_player(parent).force
+        local force = Gui.get_player(parent).force --[[@as LuaForce]]
         def.data[force] = def.data[force] or {} -- used by start index and row data
 
-        local force = Gui.get_player(parent).force --[[@as LuaForce]]
         local start_index = Elements.container.calculate_starting_research_index(force)
         for research_index = start_index, start_index + display_size - 1 do
             local row_data = Elements.milestone_table.calculate_row_data(force, research_index)
@@ -297,7 +296,7 @@ end
 --- @param research_index number
 --- @return number
 function Elements.container.get_achieved_time(force, research_index)
-    return Elements.container.data[force][research_index]
+    return assert(Elements.container.data[force][research_index])
 end
 
 --- Calculate the starting research index for a force

exp_scenario/module/gui/science_production.lua

@@ -109,7 +109,7 @@ function Elements.production_label.calculate_display_data(tooltip, value, cutoff
     end
 
     local suffix, caption = format_number(value)
-    display_data = display_data or {}
+    display_data = display_data or {} --[[@as Elements.production_label.display_data]]
     display_data.caption = caption
     display_data.suffix = suffix
     display_data.tooltip = tooltip
@@ -221,7 +221,7 @@ function Elements.science_table.calculate_row_data(force, science_pack, row_data
     end
 
     -- Return the pack data
-    row_data = row_data or {}
+    row_data = row_data or {} --[[@as ExpGui_ScienceProduction.elements.science_table.row_data]]
     row_data.visible = production.total.made > 0
     row_data.science_pack = science_pack
     row_data.icon_style = icon_style

exp_scenario/module/gui/task_list.lua

@@ -612,7 +612,7 @@ function Elements.confirm_task_button.parse(message)
     -- Trim the spaces of the string
     local trimmed = string.gsub(message, "^%s*(.-)%s*$", "%1")
     local title, body = string.match(trimmed, "(.-)\n(.*)")
-    local parsed = { title = title, body = body }
+    local parsed = { title = title, body = body } --[[@as { title: string, body: string }]]
     if not title then
         -- If it doesn't match the pattern return the str as a title
         parsed.title = trimmed

exp_util/module/module_exports.lua

@@ -284,7 +284,7 @@ function ExpUtil.format_any(value, options)
         end
         return inspect(value, { depth = options.depth or 5, indent = "", newline = "", process = ExpUtil.safe_value })
     end
-    return formatted
+    return formatted --[[@as LocalisedString]]
 end
 
 --- @alias Common.format_time_param_format "short" | "long" | "clock"
@@ -522,7 +522,7 @@ end
 
 --- Insert a copy of the given items into the found entities. If no entities are found then they will be created if possible.
 --- @param options Common.copy_items_to_surface_param
---- @return LuaEntity # The last entity inserted into
+--- @return LuaEntity? # The last entity inserted into, nil if there were no items
 function ExpUtil.copy_items_to_surface(options)
     local entity
     for item_index = 1, #options.items do
@@ -542,7 +542,7 @@ end
 
 --- Insert a copy of the given items into the found entities. If no entities are found then they will be created if possible.
 --- @param options Common.move_items_to_surface_param
---- @return LuaEntity # The last entity inserted into
+--- @return LuaEntity? # The last entity inserted into, nil if there were no items
 function ExpUtil.move_items_to_surface(options)
     local entity
     for item_index = 1, #options.items do
@@ -564,7 +564,7 @@ end
 
 --- Move the given inventory into the found entities. If no entities are found then they will be created if possible.
 --- @param options Common.transfer_inventory_to_surface_param
---- @return LuaEntity # The last entity inserted into
+--- @return LuaEntity? # The last entity inserted into, nil if there were no items
 function ExpUtil.transfer_inventory_to_surface(options)
     options.items = options.inventory
     local entity = ExpUtil.copy_items_to_surface(options)