feat: make it possible to not inline external file

rest.nvim always inlines the payload which generates humongous
(superlong) curl commands.
If you prefix your external payload with `<@` instead of `<`, rest.nvim
will pass the file to curl as-is via --data-binary @filename

Author: teto

lua/rest-nvim/curl/init.lua

@@ -102,7 +102,7 @@ local function create_callback(curl_cmd, method, url, script_str)
 
     -- This can be quite verbose so let user control it
     if config.get("result").show_curl_command then
-      vim.api.nvim_buf_set_lines(res_bufnr, 0, 0, false, { "Command :" .. curl_cmd })
+      vim.api.nvim_buf_set_lines(res_bufnr, 0, 0, false, { "Command: " .. curl_cmd })
     end
 
     if config.get("result").show_url then

lua/rest-nvim/init.lua

@@ -18,6 +18,7 @@ rest.setup = function(user_configs)
   config.set(user_configs or {})
 end
 
+
 -- run will retrieve the required request information from the current buffer
 -- and then execute curl
 -- @param verbose toggles if only a dry run with preview should be executed (true = preview)
@@ -145,23 +146,31 @@ end
 rest.run_request = function(req, opts)
   -- TODO rename result to request
   local result = req
+  local curl_raw_args = config.get("skip_ssl_verification") and vim.list_extend(result.raw, { "-k" })
+      or result.raw
   opts = vim.tbl_deep_extend(
     "force", -- use value from rightmost map
     defaultRequestOpts,
     opts or {}
   )
 
-  -- body =
+  -- if we want to pass as a file, we pass nothing to plenary
+  local spliced_body = nil
+  if not req.body.inline and req.body.filename_tpl then
+    curl_raw_args = vim.tbl_extend("force", curl_raw_args, {
+      '--data-binary', '@'..load_external_payload(req.body.filename_tpl)})
+  else
+    spliced_body = splice_body(result.headers, result.body)
+  end
 
   Opts = {
     method = result.method:lower(),
     url = result.url,
     -- plenary.curl can't set http protocol version
     -- http_version = result.http_version,
     headers = splice_headers(result.headers),
-    raw = config.get("skip_ssl_verification") and vim.list_extend(result.raw, { "-k" })
-      or result.raw,
-    body = splice_body(result.headers, result.body),
+    raw = curl_raw_args,
+    body = spliced_body,
     dry_run = opts.verbose,
     bufnr = result.bufnr,
     start_line = result.start_line,

lua/rest-nvim/request/init.lua

@@ -5,6 +5,7 @@ local config = require("rest-nvim.config")
 -- get_importfile returns in case of an imported file the absolute filename
 -- @param bufnr Buffer number, a.k.a id
 -- @param stop_line Line to stop searching
+-- @return tuple filename and whether we should inline it when invoking curl
 local function get_importfile_name(bufnr, start_line, stop_line)
   -- store old cursor position
   local oldpos = vim.fn.getcurpos()
@@ -17,10 +18,13 @@ local function get_importfile_name(bufnr, start_line, stop_line)
   if import_line > 0 then
     local fileimport_string
     local fileimport_line
+    local fileimport_inlined
     fileimport_line = vim.api.nvim_buf_get_lines(bufnr, import_line - 1, import_line, false)
-    fileimport_string =
-      string.gsub(fileimport_line[1], "<", "", 1):gsub("^%s+", ""):gsub("%s+$", "")
-    return fileimport_string
+    -- check second char against '@' (meaning "dont inline")
+    fileimport_inlined = string.sub(fileimport_line[1], 2, 2) ~= '@'
+    fileimport_string = string.gsub(fileimport_line[1], "<@?", "", 1):gsub("^%s+", ""):gsub("%s+$", "")
+    return fileimport_inlined, fileimport_string
+
   end
   return nil
 end
@@ -35,10 +39,10 @@ end
 -- @return table { external = bool; filename_tpl or body_tpl; }
 local function get_body(bufnr, start_line, stop_line)
   -- first check if the body should be imported from an external file
-  local importfile = get_importfile_name(bufnr, start_line, stop_line)
+  local inline, importfile = get_importfile_name(bufnr, start_line, stop_line)
   local lines -- an array of strings
   if importfile ~= nil then
-    return { external = true, filename_tpl = importfile }
+    return { external = true; inline = inline; filename_tpl = importfile }
   else
     lines = vim.api.nvim_buf_get_lines(bufnr, start_line, stop_line, false)
   end
@@ -59,7 +63,7 @@ local function get_body(bufnr, start_line, stop_line)
     end
   end
 
-  return { external = false, body_tpl = lines2 }
+  return { external = false; inline = false; body_tpl = lines2 }
 end
 
 local function get_response_script(bufnr, start_line, stop_line)