Fix RegexpError when parsing command

lib/slack-ruby-bot/commands/base.rb

@@ -47,8 +47,9 @@ def self.operator(*values, &block)
 
       def self.command(*values, &block)
         values.each do |value|
-          match Regexp.new("^(?<bot>[\\w[:punct:]@<>]*)[\\s]+(?<command>#{value})$", Regexp::IGNORECASE), &block
-          match Regexp.new("^(?<bot>[\\w[:punct:]@<>]*)[\\s]+(?<command>#{value})[\\s]+(?<expression>.*)$", Regexp::IGNORECASE), &block
+          escaped = Regexp.escape(value)
+          match Regexp.new("^(?<bot>[\\w[:punct:]@<>]*)[\\s]+(?<command>#{escaped})$", Regexp::IGNORECASE), &block
+          match Regexp.new("^(?<bot>[\\w[:punct:]@<>]*)[\\s]+(?<command>#{escaped})[\\s]+(?<expression>.*)$", Regexp::IGNORECASE), &block
         end
       end
 

spec/slack-ruby-bot/commands/commands_regexp_escape_spec.rb

@@ -0,0 +1,17 @@
+require 'spec_helper'
+
+describe SlackRubyBot::Commands do
+  let! :command do
+    Class.new(SlackRubyBot::Commands::Base) do
+      command '(' do |client, data, match|
+        send_message client, data.channel, "#{match[:command]}: #{match[:expression]}"
+      end
+    end
+  end
+  def app
+    SlackRubyBot::App.new
+  end
+  it 'does not return error' do
+    expect(message: "#{SlackRubyBot.config.user} ( /").to respond_with_slack_message('(: /')
+  end
+end