enhance connection_string parser

* use URI module to parse connection string
* convert types in parser, not in connect function
* add ability to select database

Author: artemeff

lib/exredis.ex

@@ -16,20 +16,15 @@ defmodule Exredis do
   @doc """
   Connect to the Redis server using a connection string:
 
-  * `start_using_connection_string("redis://user:password@127.0.0.1:6379")`
+  * `start_using_connection_string("redis://user:password@127.0.0.1:6379/0")`
   * `start_using_connection_string("redis://127.0.0.1:6379")`
 
   Returns pid of the connected client
   """
   @spec start_using_connection_string(binary, :no_reconnect | integer) :: pid
-  def start_using_connection_string(connection_string, database \\ 0, reconnect_sleep \\ :no_reconnect)  do
+  def start_using_connection_string(connection_string, reconnect_sleep \\ :no_reconnect)  do
     config = Exredis.ConnectionString.parse(connection_string)
-
-    # FIXME: Make the "start" method use binary strings as well and put the translation at the lowest possible level?
-    host = config.host |> String.to_char_list
-    password = config.password |> String.to_char_list
-    port = config.port
-    start(host, port, database, password, reconnect_sleep)
+    start(config.host, config.port, config.db, config.password, reconnect_sleep)
   end
 
   @doc """

lib/exredis/connection_string.ex

@@ -1,40 +1,26 @@
 defmodule Exredis.ConnectionString do
   defmodule Config do
-    defstruct host: nil, port: nil, password: nil
+    defstruct host: nil, port: nil, password: nil, db: nil
   end
 
   def parse(connection_string) do
-    connection_string
-      |> extract_auth_and_path
-      |> convert_to_config
+    uri = URI.parse(connection_string)
+    
+    %Config{
+      host:     uri.host |> String.to_char_list,
+      port:     uri.port,
+      password: uri.userinfo |> parse_password,
+      db:       uri.path |> parse_db
+    }
   end
 
-  defp extract_auth_and_path(connection_string) do
-    connection_string
-      |> String.split("/")
-      |> Enum.at(-1)
-      |> String.split("@")
-  end
-
-  defp convert_to_config([ auth, path ]) do
-    [ host, port ] = parse_host_and_port(path)
-    password = parse_password(auth)
-    %Config{ host: host, port: port, password: password }
-  end
-
-  defp convert_to_config([ path ]) do
-    [ host, port ] = parse_host_and_port(path)
-    password = ""
-    %Config{ host: host, port: port, password: password }
-  end
-
-  defp parse_host_and_port(path) do
-    [ host, port ] = path |> String.split(":")
-    [ host, String.to_integer(port) ]
+  defp parse_db(nil), do: 0
+  defp parse_db(path) do
+    path |> String.split("/") |> Enum.at(1)
   end
 
+  defp parse_password(nil), do: ''
   defp parse_password(auth) do
-    [ _user, password ] = auth |> String.split(":")
-    password
+    auth |> String.split(":") |> Enum.at(1) |> String.to_char_list
   end
 end

test/connection_string_test.exs

@@ -5,15 +5,30 @@ defmodule ConnectionStringTest do
 
   test "parsing a connection string" do
     config = Exredis.ConnectionString.parse("redis://user:password@host:1234")
-    assert config.host == "host"
+    assert config.host == 'host'
     assert config.port == 1234
-    assert config.password == "password"
+    assert config.password == 'password'
+  end
+
+  test "parsing a connection string with db" do
+    config = Exredis.ConnectionString.parse("redis://user:password@host:1234/10")
+    assert config.host == 'host'
+    assert config.port == 1234
+    assert config.password == 'password'
+    assert config.db == "10"
+  end
+
+  test "parsing a connection string without user" do
+    config = Exredis.ConnectionString.parse("redis://:password@host:1234")
+    assert config.host == 'host'
+    assert config.port == 1234
+    assert config.password == 'password'
   end
 
   test "parsing a connection string without password" do
     config = Exredis.ConnectionString.parse("redis://host:1234")
-    assert config.host == "host"
+    assert config.host == 'host'
     assert config.port == 1234
-    assert config.password == ""
+    assert config.password == ''
   end
 end