added Luacheck GitHub action (#210)

* added shields.io elements
* #209 luacheck action
* #209 cleanup to pass luacheck
* added check statuses to readme

reactor-plc/plc.lua

@@ -68,11 +68,6 @@ function plc.rps_init(reactor, is_formed, emer_cool)
         end
     end
 
-    -- clear reactor access fault flag
-    local function _clear_fault()
-        self.state[state_keys.fault] = false
-    end
-
     -- set emergency coolant control (if configured)
     ---@param state boolean true to enable emergency coolant, false to disable
     local function _set_emer_cool(state)
@@ -779,7 +774,6 @@ function plc.comms(id, version, modem, local_port, server_port, range, reactor,
     ---@param setpoints setpoints setpoint control table
     function public.handle_packet(packet, plc_state, setpoints)
         -- print a log message to the terminal as long as the UI isn't running
-        local function println(message) if not plc_state.fp_ok then util.println(message) end end
         local function println_ts(message) if not plc_state.fp_ok then util.println_ts(message) end end
 
         -- handle packets now that we have prints setup

reactor-plc/startup.lua

@@ -20,9 +20,7 @@ local threads  = require("reactor-plc.threads")
 
 local R_PLC_VERSION = "v1.1.5"
 
-local print = util.print
 local println = util.println
-local print_ts = util.print_ts
 local println_ts = util.println_ts
 
 ----------------------------------------
@@ -176,8 +174,9 @@ local function main()
 
         -- front panel time!
         if not renderer.ui_ready() then
-            local message = nil
+            local message
             plc_state.fp_ok, message = pcall(renderer.start_ui)
+
             if not plc_state.fp_ok then
                 renderer.close_ui()
                 println_ts(util.c("UI error: ", message))

reactor-plc/threads.lua

@@ -34,7 +34,6 @@ local MQ__COMM_CMD = {
 ---@param init function
 function threads.thread__main(smem, init)
     -- print a log message to the terminal as long as the UI isn't running
-    local function println(message) if not smem.plc_state.fp_ok then util.println(message) end end
     local function println_ts(message) if not smem.plc_state.fp_ok then util.println_ts(message) end end
 
     ---@class parallel_thread
@@ -307,7 +306,6 @@ end
 ---@param smem plc_shared_memory
 function threads.thread__rps(smem)
     -- print a log message to the terminal as long as the UI isn't running
-    local function println(message) if not smem.plc_state.fp_ok then util.println(message) end end
     local function println_ts(message) if not smem.plc_state.fp_ok then util.println_ts(message) end end
 
     ---@class parallel_thread
@@ -682,7 +680,7 @@ function threads.thread__setpoint_control(smem)
                             -- we yielded, check enable again
                             if setpoints.burn_rate_en and (type(current_burn_rate) == "number") and (current_burn_rate ~= setpoints.burn_rate) then
                                 -- calculate new burn rate
-                                local new_burn_rate = current_burn_rate
+                                local new_burn_rate ---@type number
 
                                 if setpoints.burn_rate > current_burn_rate then
                                     -- need to ramp up