Add case-insensitive table lookups, and use for host and content-type. (

#236)

A new utility function called `key` takes a table and a key. It loops
through the table items, comparing the each key with the given search
key in a case-insensitive manner. Return the first matching key;
otherwise, return the given search key. This allows operations like
these to be performed:

```lua
local t = {s=37, S=73}
t[utils.key(t,'a')] = 1  -- Insert a:1              t == {s=37,S=73,a=1}
y = t[utils.key(t,'a')]  -- Find 'a'                y == 1
z = t[utils.key(t,'A')]  -- Find 'A' (same as 'a')  z == 1
m = t[utils.key(t,'b')]  -- Show 'b' is missing.    m == nil
k = utils.key(t,'s')     -- Which 's/S' is first?   k is indeterminate
l = t['s']               -- Get 's' and 'S'         l = 37
u = t['S']               -- in the usual manner.    u = 73
t[utils.key(t,'a')] = nil  -- Delete 'a'            t == {s=37, S=73}
```

As implied by the `k = ` example above, lua associative tables are
unordered, so there's no guarantee that 's' (or 'S') is the first one to
be found. In this context, that shouldn't be too much of an issue.

Use this new function to find the 'Host' and 'Content-Type' headers'
values no matter in what case they were defined.

lua/rest-nvim/curl/init.lua

@@ -103,14 +103,9 @@ local function create_callback(curl_cmd, opts)
       return
     end
     local res_bufnr = M.get_or_create_buf()
-    local content_type = nil
-
-    -- get content type
-    for _, header in ipairs(res.headers) do
-      if string.lower(header):find("^content%-type") then
-        content_type = header:match("application/([-a-z]+)") or header:match("text/(%l+)")
-        break
-      end
+    local content_type = res.headers[utils.key(res.headers,'content-type')]
+    if content_type then
+      content_type = content_type:match("application/([-a-z]+)") or content_type:match("text/(%l+)")
     end
 
     if script_str ~= nil then

lua/rest-nvim/init.lua

@@ -101,13 +101,7 @@ local function splice_body(headers, payload)
   else
     lines = payload.body_tpl
   end
-  local content_type = ""
-  for key, val in pairs(headers) do
-    if string.lower(key) == "content-type" then
-      content_type = val
-      break
-    end
-  end
+  local content_type = headers[utils.key(headers,"content-type")] or ""
   local has_json = content_type:find("application/[^ ]*json")
 
   local body = ""

lua/rest-nvim/request/init.lua

@@ -286,12 +286,9 @@ M.buf_get_request = function(bufnr, curpos)
 
   local curl_args, body_start = get_curl_args(bufnr, headers_end, end_line)
 
-  if headers["host"] ~= nil then
-    headers["host"] = headers["host"]:gsub("%s+", "")
-    headers["host"] = string.gsub(headers["host"], "%s+", "")
-    parsed_url.url = headers["host"] .. parsed_url.url
-    headers["host"] = nil
-  end
+  local host = headers[utils.key(headers,"host")] or ""
+  parsed_url.url = host:gsub("%s+", "") .. parsed_url.url
+  headers[utils.key(headers,"host")] = nil
 
   local body = get_body(bufnr, body_start, end_line)
 

lua/rest-nvim/utils/init.lua

@@ -107,6 +107,7 @@ M.get_file_variables = function()
   end
   return variables
 end
+
 -- Gets the variables from the currently selected env_file
 M.get_env_variables = function()
   local variables = {}
@@ -286,6 +287,19 @@ M.has_value = function(tbl, str)
   return false
 end
 
+-- key returns the provided table's key that matches the given case-insensitive pattern.
+-- if not found, return the given key.
+-- @param tbl Table to iterate over
+-- @param key The key to be searched in the table
+M.key = function(tbl, key)
+  for tbl_key, _ in pairs(tbl) do
+    if string.lower(tbl_key) == string.lower(key) then
+      return tbl_key
+    end
+  end
+  return key
+end
+
 -- tbl_to_str recursively converts the provided table into a json string
 -- @param tbl Table to convert into a String
 -- @param json If the string should use a key:value syntax

tests/get_with_host.http

@@ -1,7 +1,7 @@
 ###
 
 GET /api/users?page=5
-Host: https://reqres.in
+host: https://reqres.in
 
 ###
 

tests/main_spec.lua

@@ -6,6 +6,7 @@ describe("rest testing framework", function()
     assert(rest.run_file("tests/basic_get.http", opts) == true)
     assert(rest.run_file("tests/post_json_form.http", opts) == true)
     assert(rest.run_file("tests/post_create_user.http", opts) == true)
+    assert(rest.run_file("tests/get_with_host.http", opts) == true)
     assert(rest.run_file("tests/put_update_user.http", opts) == true)
     assert(rest.run_file("tests/patch_update_user.http", opts) == true)
     assert(rest.run_file("tests/delete.http", opts) == true)