[resty.url] allow parsed url to be serialized back

apicast/src/resty/url.lua

@@ -2,6 +2,7 @@ local tostring = tostring
 local re_match = ngx.re.match
 local concat = table.concat
 local tonumber = tonumber
+local setmetatable = setmetatable
 
 local _M = {
   _VERSION = '0.1'
@@ -51,14 +52,14 @@ function _M.parse(url, protocol)
   end
 
   -- https://tools.ietf.org/html/rfc3986#section-3
-  return {
+  return setmetatable({
     scheme = parts[1] or nil,
     user = parts[2] or nil,
     password = parts[3] or nil,
     host = parts[4] or nil,
     port = tonumber(parts[5]),
     path = parts[6] or nil
-  }
+  }, { __tostring = function() return url end })
 end
 
 function _M.join(...)

spec/resty/url_spec.lua

@@ -1,4 +1,5 @@
 local url = require 'resty.url'
+local tostring = tostring
 
 describe('resty.url', function()
 
@@ -72,6 +73,11 @@ describe('resty.url', function()
     it('works with redis DSN', function()
       assert.same({ scheme = 'redis', user = 'user', password = 'pass', host = 'localhost', port = 6379, path = '/42' }, parse('redis://user:pass@localhost:6379/42', 'redis'))
     end)
+
+    it('serializes back', function()
+      local uri = 'https://user:password@example.com:1234/path?query'
+      assert.equal(uri, tostring(parse(uri)))
+    end)
   end)
 
   describe('.join', function()