fix(form): fix binary multipart-form-data

docs/docs/usage/sending-form-data.md

@@ -16,3 +16,36 @@ name={{name}}&
 age={{age}}
 ```
 
+## Sending multipart form data
+
+You can send multipart form data in Kulala by using the `multipart/form-data` content type.
+
+```http title="multipart.http"
+# @file-to-variable LOGO_FILE_VAR ./../../logo.png
+POST https://httpbin.org/post HTTP/1.1
+Content-Type: multipart/form-data; boundary=----WebKitFormBoundary{{$timestamp}}
+
+------WebKitFormBoundary{{$timestamp}}
+Content-Disposition: form-data; name="logo"; filename="logo.png"
+Content-Type: image/jpeg
+
+{{LOGO_FILE_VAR}}
+
+------WebKitFormBoundary{{$timestamp}}
+Content-Disposition: form-data; name="x"
+
+0
+------WebKitFormBoundary{{$timestamp}}
+Content-Disposition: form-data; name="y"
+
+1.4333333333333333
+------WebKitFormBoundary{{$timestamp}}
+Content-Disposition: form-data; name="w"
+
+514.5666666666667
+------WebKitFormBoundary{{$timestamp}}
+Content-Disposition: form-data; name="h"
+
+514.5666666666667
+------WebKitFormBoundary{{$timestamp}}--
+```

lua/kulala/parser/init.lua

@@ -413,6 +413,7 @@ local function extend_document_variables(document_variables, request)
         local kv = vim.split(metadata.value, " ")
         local variable_name = kv[1]
         local file_path = kv[2]
+        file_path = FS.get_file_path(file_path)
         local file_contents = FS.read_file(file_path)
         if file_contents then
           document_variables[variable_name] = file_contents
@@ -574,8 +575,13 @@ function M.parse(start_request_linenr)
         res.headers["content-type"] = "application/json"
       end
     elseif res.headers["content-type"]:find("^multipart/form%-data") then
-      table.insert(res.cmd, "--data-binary")
-      table.insert(res.cmd, res.body)
+      local tmp_file = FS.get_binary_temp_file(res.body)
+      if tmp_file ~= nil then
+        table.insert(res.cmd, "--data-binary")
+        table.insert(res.cmd, "@" .. tmp_file)
+      else
+        Logger.error("Failed to create a temporary file for the binary request body")
+      end
     else
       table.insert(res.cmd, "--data")
       table.insert(res.cmd, res.body)

lua/kulala/utils/fs.lua

@@ -10,6 +10,27 @@ M.join_paths = function(...)
   return table.concat({ ... }, M.ps)
 end
 
+---Returns true if the path is absolute, false otherwise
+M.is_absolute_path = function(path)
+  if path:match("^/") or path:match("^%a:\\") then
+    return true
+  end
+  return false
+end
+
+---Either returns the absolute path if the path is already absolute or
+---joins the path with the current buffer directory
+M.get_file_path = function(path)
+  if M.is_absolute_path(path) then
+    return path
+  end
+  local buffer_dir = vim.fn.expand("%:p:h")
+  if path:sub(1, 2) == "./" or path:sub(1, 2) == ".\\" then
+    path = path:sub(3)
+  end
+  return M.join_paths(buffer_dir, path)
+end
+
 -- This is mainly used for determining if the current buffer is a non-http file
 -- and therefore maybe we need to parse a fenced code block
 M.is_non_http_file = function()
@@ -232,6 +253,17 @@ M.read_file = function(filename)
   return content
 end
 
+M.get_binary_temp_file = function(content)
+  local tmp_file = vim.fn.tempname()
+  local f = io.open(tmp_file, "wb")
+  if f == nil then
+    return nil
+  end
+  f:write(content)
+  f:close()
+  return tmp_file
+end
+
 ---Read file lines
 ---@param filename string
 ---@return string[]