Introduce URI.decode_www_form/1 function

Author: lexmag

lib/elixir/lib/uri.ex

@@ -126,8 +126,10 @@ defmodule URI do
 
     current =
       case :binary.split(first, "=") do
-        [ key, value ] -> {decode(key), decode(value)}
-        [ key ]        -> {decode(key), nil}
+        [key, value] ->
+          {decode_www_form(key), decode_www_form(value)}
+        [key] ->
+          {decode_www_form(key), nil}
       end
 
     {current, next}
@@ -236,6 +238,22 @@ defmodule URI do
       raise ArgumentError, "malformed URI #{inspect uri}"
   end
 
+  @doc """
+  Decode a string as "x-www-urlencoded".
+
+  ## Examples
+
+      iex> URI.decode_www_form("%3Call+in%2F")
+      "<all in/"
+
+  """
+  def decode_www_form(str) do
+    String.split(str, "+") |> Enum.map_join(" ", &unpercent/1)
+  catch
+    :malformed_uri ->
+      raise ArgumentError, "malformed URI #{inspect str}"
+  end
+
   defp unpercent(<<?%, hex_1, hex_2, tail :: binary>>) do
     <<bsl(hex_to_dec(hex_1), 4) + hex_to_dec(hex_2)>> <> unpercent(tail)
   end

lib/elixir/test/elixir/uri_test.exs

@@ -29,7 +29,7 @@ defmodule URITest do
     assert URI.decode_query("", []) == []
     assert URI.decode_query("", %{}) == %{}
 
-    assert URI.decode_query("q=search%20query&cookie=ab%26cd&block%20buster=") ==
+    assert URI.decode_query("q=search%20query&cookie=ab%26cd&block+buster=") ==
            %{"block buster" => "", "cookie" => "ab&cd", "q" => "search query"}
 
     assert URI.decode_query("something=weird%3Dhappening") ==
@@ -46,7 +46,7 @@ defmodule URITest do
   test :decoder do
     decoder  = URI.query_decoder("q=search%20query&cookie=ab%26cd&block%20buster=")
     expected = [{"q", "search query"}, {"cookie", "ab&cd"}, {"block buster", ""}]
-    assert Enum.map(decoder, fn(x) -> x end) == expected
+    assert Enum.map(decoder, &(&1)) == expected
   end
 
   test :decode do
@@ -62,6 +62,11 @@ defmodule URITest do
     end
   end
 
+  test :decode_www_form do
+    assert URI.decode_www_form("%3Eval+ue%2B") == ">val ue+"
+    assert URI.decode_www_form("%E3%82%86+") == "ゆ "
+  end
+
   test :parse_http do
     assert %URI{scheme: "http", host: "foo.com", path: "/path/to/something",
                 query: "foo=bar&bar=foo", fragment: "fragment", port: 80,