Fix warning for pattern match

Gemfile

@@ -4,10 +4,11 @@ gemspec
 
 group :test do
   gem "rspec"
-  gem "rubocop", "~> 0.29.1", :platform => [:ruby_20, :ruby_21]
+  gem "rubocop", "~> 0.29.1", :platform => [:ruby_20, :ruby_21, :ruby_22]
 end
 
 group :development do
   gem "method_profiler"
   gem "ruby-prof"
+  gem "rake"
 end

README.md

@@ -53,6 +53,18 @@ Check out [this awesome tutorial](http://egonschiele.github.com/contracts.ruby).
 
 Check out [this screencast](https://vimeo.com/85883356).
 
+## Development
+
+To get started do the following:
+
+1. Install required gems for development
+
+  `bundle install`
+
+2. Run our test suite
+
+  `bundle exec rake`
+
 ## Performance
 
 Using contracts.ruby results in very little slowdown. Check out [this blog post](http://adit.io/posts/2013-03-04-How-I-Made-My-Ruby-Project-10x-Faster.html#seconds-6) for more info.

Rakefile

@@ -0,0 +1,11 @@
+if RUBY_VERSION >= "2"
+  task :default => [:spec, :rubocop]
+
+  require "rubocop/rake_task"
+  RuboCop::RakeTask.new
+else
+  task :default => [:spec]
+end
+
+require "rspec/core/rake_task"
+RSpec::Core::RakeTask.new(:spec)

lib/contracts.rb

@@ -110,6 +110,8 @@ def initialize(klass, method, *contracts)
 
     @ret_validator = Contract.make_validator(ret_contract)
 
+    @pattern_match = false
+
     # == @has_proc_contract
     last_contract = args_contracts.last
     is_a_proc = last_contract.is_a?(Class) && (last_contract <= Proc || last_contract <= Method)
@@ -251,7 +253,7 @@ def maybe_append_options! args, blk
 
   # Used to determine type of failure exception this contract should raise in case of failure
   def failure_exception
-    if @pattern_match
+    if pattern_match?
       PatternMatchingError
     else
       ParamContractError
@@ -266,6 +268,6 @@ def pattern_match!
 
   # Used to determine if contract is a pattern matching contract
   def pattern_match?
-    @pattern_match
+    @pattern_match == true
   end
 end