fix: #106 #104 No longer transform underscores

Author: pintsized

lib/resty/http_headers.lua

@@ -1,74 +1,38 @@
-local   rawget, rawset, setmetatable =
-        rawget, rawset, setmetatable
-
-local str_find, str_lower, str_sub =
-      string.find, string.lower, string.sub
+local rawget, rawset, setmetatable =
+    rawget, rawset, setmetatable
 
+local str_lower = string.lower
 
 local _M = {
     _VERSION = '0.10',
 }
 
 
-local function hyphenate(k)
-    local k_hyphened = ""
-    local match = false
-    local prev_pos = 0
-
-    repeat
-        local pos = str_find(k, "_", prev_pos, true)
-        if pos then
-            match = true
-            k_hyphened =  k_hyphened .. str_sub(k, prev_pos, pos - 1) .. "-"
-        elseif match == false then
-            -- Didn't find an underscore and first check
-            return k
-        else
-            -- No more underscores, append the rest of the key
-            k_hyphened = k_hyphened .. str_sub(k, prev_pos)
-            break
-        end
-        prev_pos = pos + 1
-    until not pos
-
-    return k_hyphened
-end
-
-
 -- Returns an empty headers table with internalised case normalisation.
--- Supports the same cases as in ngx_lua:
---
--- headers.content_length
--- headers["content-length"]
--- headers["Content-Length"]
-function _M.new(self)
+function _M.new()
     local mt = {
         normalised = {},
     }
 
     mt.__index = function(t, k)
-        local k_hyphened = hyphenate(k)
-        local k_normalised = str_lower(k_hyphened)
-        return rawget(t, mt.normalised[k_normalised])
+        return rawget(t, mt.normalised[str_lower(k)])
     end
 
-    -- First check the normalised table. If there's no match (first time) add an entry for
-    -- our current case in the normalised table. This is to preserve the human (prettier) case
-    -- instead of outputting lowercased header names.
-    --
-    -- If there's a match, we're being updated, just with a different case for the key. We use
-    -- the normalised table to give us the original key, and perorm a rawset().
     mt.__newindex = function(t, k, v)
-        -- we support underscore syntax, so always hyphenate.
-        local k_hyphened = hyphenate(k)
-
-        -- lowercase hyphenated is "normalised"
-        local k_normalised = str_lower(k_hyphened)
+        local k_normalised = str_lower(k)
 
+        -- First time seeing this header field?
         if not mt.normalised[k_normalised] then
-            mt.normalised[k_normalised] = k_hyphened
-            rawset(t, k_hyphened, v)
+            -- Create a lowercased entry in the metatable proxy, with the value
+            -- of the given field case
+            mt.normalised[k_normalised] = k
+
+            -- Set the header using the given field case
+            rawset(t, k, v)
         else
+            -- We're being updated just with a different field case. Use the
+            -- normalised metatable proxy to give us the original key case, and
+            -- perorm a rawset() to update the value.
             rawset(t, mt.normalised[k_normalised], v)
         end
     end