From 992789d477500b86b38d760d06c0511fd15706f5 Mon Sep 17 00:00:00 2001
From: Ryan Orr <ryanorr12@gmail.com>
Date: Sat, 19 Mar 2011 13:15:21 -0500
Subject: [PATCH] Checks for Enumerable content uniqueness

---
 .../lib/active_support/core_ext/enumerable.rb      |   11 +++++++++++
 activesupport/test/core_ext/enumerable_test.rb     |   10 ++++++++++
 2 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/activesupport/lib/active_support/core_ext/enumerable.rb b/activesupport/lib/active_support/core_ext/enumerable.rb
index 6d7f771..937ada1 100644
--- a/activesupport/lib/active_support/core_ext/enumerable.rb
+++ b/activesupport/lib/active_support/core_ext/enumerable.rb
@@ -100,6 +100,17 @@ module Enumerable
     size > 1
   end
 
+  # Returns true if the collection has no duplicated content.
+  # Can be called with a block too, much like any?, so people.uniq? { |p| p.age > 26 } returns true if only 1 person is over 26.
+  def uniq?(&block)
+    if block_given?
+      collection = select(&block)
+      collection.uniq.size == collection.size
+    else
+      uniq.size == size
+    end
+  end
+
   # The negative of the Enumerable#include?. Returns true if the collection does not include the object.
   def exclude?(object)
     !include?(object)
diff --git a/activesupport/test/core_ext/enumerable_test.rb b/activesupport/test/core_ext/enumerable_test.rb
index 4655bfe..d8aa67e 100644
--- a/activesupport/test/core_ext/enumerable_test.rb
+++ b/activesupport/test/core_ext/enumerable_test.rb
@@ -90,6 +90,16 @@ class EnumerableTests < Test::Unit::TestCase
     assert [ 1, 2, 2 ].many? {|x| x > 1 }
   end
 
+  def test_uniq
+    assert [].uniq?
+    assert [ 1 ].uniq?
+    assert [ 1, 2 ].uniq?
+    assert ![ 1, 1 ].uniq?
+
+    assert [ 1, 1, 2 ].uniq? { |x| x > 1 }
+    assert ![ 1, 2, 2].uniq? { |x| x > 1 }
+  end
+
   def test_exclude?
     assert [ 1 ].exclude?(2)
     assert ![ 1 ].exclude?(1)
-- 
1.7.4.1