Merge pull request #2392 from lexmag/improve-uri

José Valim · José Valim · commit 8cb4c719f920 · 2014-06-11T11:15:14.000+02:00
Make `URI.encode/1` to conform to RFC 3986. Introduce `URI.encode/2` function.
diff --git a/lib/elixir/lib/uri.ex b/lib/elixir/lib/uri.ex
@@ -145,30 +145,53 @@ defmodule URI do
     encode(to_string(k)) <> "=" <> encode(to_string(v))
   end
 
+  # RFC3986, section 2.2
+  @doc """
+  Returns true if the character is a "reserved" character in a URI.
+  """
+  def char_reserved?(c) do
+    c in ':/?#[]@!$&\'()*+,;='
+  end
+
+  # RFC3986, section 2.3
+  @doc """
+  Returns true if the character is a "unreserved" character in a URI.
+  """
+  def char_unreserved?(c) do
+    c in ?0..?9 or
+    c in ?a..?z or
+    c in ?A..?Z or
+    c in '~_-.'
+  end
+
+  @doc """
+  Returns true if the character is allowed unescaped in a URI.
+  """
+  def char_unescaped?(c) do
+    char_reserved?(c) or char_unreserved?(c)
+  end
+
   @doc """
   Percent-escape a URI.
+  Accepts `predicate` function as an argument to specify if char can be left as is.
 
   ## Example
 
-      iex> URI.encode("http://elixir-lang.org/getting_started/2.html")
-      "http%3A%2F%2Felixir-lang.org%2Fgetting_started%2F2.html"
+      iex> URI.encode("ftp://s-ite.tld/?value=put it+й")
+      "ftp://s-ite.tld/?value=put%20it+%D0%B9"
 
   """
-  def encode(s), do: for(<<c <- s>>, into: "", do: percent(c))
-
-  defp percent(32), do: <<?+>>
-  defp percent(?-), do: <<?->>
-  defp percent(?_), do: <<?_>>
-  defp percent(?.), do: <<?.>>
-
-  defp percent(c)
-      when c >= ?0 and c <= ?9
-      when c >= ?a and c <= ?z
-      when c >= ?A and c <= ?Z do
-    <<c>>
+  def encode(str, predicate \\ &char_unescaped?/1) do
+    for <<c <- str>>, into: "", do: percent(c, predicate)
   end
 
-  defp percent(c), do: "%" <> hex(bsr(c, 4)) <> hex(band(c, 15))
+  defp percent(c, predicate) do
+    if predicate.(c) do
+      <<c>>
+    else
+      "%" <> hex(bsr(c, 4)) <> hex(band(c, 15))
+    end
+  end
 
   defp hex(n) when n <= 9, do: <<n + ?0>>
   defp hex(n), do: <<n + ?A - 10>>
@@ -187,25 +210,22 @@ defmodule URI do
   end
 
   def decode(<<?%, hex1, hex2, tail :: binary >>, uri) do
-    << bsl(hex2dec(hex1, uri), 4) + hex2dec(hex2, uri) >> <> decode(tail, uri)
+    <<bsl(hex_to_dec(hex1, uri), 4) + hex_to_dec(hex2, uri)>> <> decode(tail, uri)
   end
 
   def decode(<<head, tail :: binary >>, uri) do
-    <<check_plus(head)>> <> decode(tail, uri)
+    <<head>> <> decode(tail, uri)
   end
 
   def decode(<<>>, _uri), do: <<>>
 
-  defp hex2dec(n, _uri) when n in ?A..?F, do: n - ?A + 10
-  defp hex2dec(n, _uri) when n in ?a..?f, do: n - ?a + 10
-  defp hex2dec(n, _uri) when n in ?0..?9, do: n - ?0
-  defp hex2dec(_n, uri) do
+  defp hex_to_dec(n, _uri) when n in ?A..?F, do: n - ?A + 10
+  defp hex_to_dec(n, _uri) when n in ?a..?f, do: n - ?a + 10
+  defp hex_to_dec(n, _uri) when n in ?0..?9, do: n - ?0
+  defp hex_to_dec(_n, uri) do
     raise ArgumentError, "malformed URI #{inspect uri}"
   end
 
-  defp check_plus(?+), do: 32
-  defp check_plus(c),  do: c
-
   @doc """
   Parses a URI into components.
 
diff --git a/lib/elixir/test/elixir/uri_test.exs b/lib/elixir/test/elixir/uri_test.exs
@@ -3,10 +3,10 @@ Code.require_file "test_helper.exs", __DIR__
 defmodule URITest do
   use ExUnit.Case, async: true
 
-  test :encode_with_binary do
-    raw = <<13, 10, 38, 60, 62, 34, 32, 227, 130, 134, 227, 130, 147, 227, 130, 134, 227, 130, 147>>
-    expected = "%0D%0A%26%3C%3E%22+%E3%82%86%E3%82%93%E3%82%86%E3%82%93"
-    assert URI.encode(raw) == expected
+  test :encode do
+    assert URI.encode("4_test.is-s~") == "4_test.is-s~"
+    assert URI.encode("\r\n&<%>\" ゆ", &URI.char_unreserved?/1) ==
+           "%0D%0A%26%3C%25%3E%22%20%E3%82%86"
   end
 
   test :encode_query do
@@ -44,11 +44,12 @@ defmodule URITest do
   end
 
   test :decode do
-    data_to_be_decoded = "%26%3C%3E%22+%E3%82%86%E3%82%93%E3%82%86%E3%82%93"
-    assert URI.decode(data_to_be_decoded) == "&<>\" ゆんゆん"
+    assert URI.decode("%0D%0A%26%3C%25%3E%22%20%E3%82%86") == "\r\n&<%>\" ゆ"
+    assert URI.decode("%2f%41%4a%55") == "/AJU"
+    assert URI.decode("4_t+st.is-s~") == "4_t+st.is-s~"
 
-    assert_raise ArgumentError, ~r/malformed URI/, fn ->
-      assert URI.decode("% invalid")
+    assert_raise ArgumentError, ~R/malformed URI/, fn ->
+      URI.decode("% invalid")
     end
   end
 
@@ -180,9 +181,4 @@ defmodule URITest do
     assert to_string(URI.parse("http://google.com?q=lol")) == "http://google.com?q=lol"
     assert to_string(URI.parse("http://google.com?q=lol#omg")) == "http://google.com?q=lol#omg"
   end
-
-  test :escape do
-    assert URI.decode("%2f%41%4a%55") == "/AJU"
-    assert URI.decode("%2F%41%4A%55") == "/AJU"
-  end
 end
