fixup! philips-hue: Add util for tracking number of items in KV table

Author: NoahCornell

drivers/SmartThings/philips-hue/src/utils/kv_counter.lua

@@ -1,12 +1,26 @@
 --- Table with metamethods to track the number of items inside of a table including KV pairs.
 local KVCounter = {}
 
+-- Helper function to implement next on KVCounter.
+-- There is no metamethod to do this but is useful for getting a value without knowing the keys.
+local function kv_counter_next(t, index)
+  local mt = getmetatable(t)
+  return next(mt.inner, index)
+end
+
 local function kv_counter_index(t, k)
   local mt = getmetatable(t)
+
+  if k == "next" then
+    return kv_counter_next
+  end
+
   return mt.inner[k]
 end
 
-local function kv_coutner_newindex(t, k, v)
+local function kv_counter_newindex(t, k, v)
+  assert(k ~= "first", "next is an unallowed key in KVCounter")
+
   local mt = getmetatable(t)
   local existed = mt.inner[k] ~= nil
   if existed and v == nil then
@@ -31,7 +45,7 @@ local function kv_counter_factory()
   local mt = {
     -- Avoid blowing up lua closures by defining these outside of the function.
     __index = kv_counter_index,
-    __newindex = kv_coutner_newindex,
+    __newindex = kv_counter_newindex,
     __pairs = kv_counter_pairs,
     __len = kv_counter_len,
     count = 0,