Added Enumerable#none? to check that none of the elements match the block [#1408 state:committed]

Signed-off-by: David Heinemeier Hansson <david@loudthinking.com>

3 files changed, 21 insertions, 0 deletions

diff --git a/activesupport/CHANGELOG b/activesupport/CHANGELOG
index 16d78e0201..0a4f295568 100644
--- a/activesupport/CHANGELOG
+++ b/activesupport/CHANGELOG
@@ -1,5 +1,7 @@
 *2.3.0/3.0*
 
+* Added Enumerable#none? to check that none of the elements match the block #1408 [Damian Janowski]
+
 * TimeZone offset tests: use current_period, to ensure TimeZone#utc_offset is up-to-date [Geoff Buesing]
 
 * Update bundled TZInfo to 0.3.12 [Geoff Buesing]
diff --git a/activesupport/lib/active_support/core_ext/enumerable.rb b/activesupport/lib/active_support/core_ext/enumerable.rb
index 788f3a7e9e..12659d7008 100644
--- a/activesupport/lib/active_support/core_ext/enumerable.rb
+++ b/activesupport/lib/active_support/core_ext/enumerable.rb
@@ -104,4 +104,13 @@ module Enumerable
     size = block_given? ? select(&block).size : self.size
     size > 1
   end
+
+  # Returns true if none of the elements match the given block.
+  # 
+  #   success = responses.none? {|r| r.status / 100 == 3 }
+  #
+  def none?(&block)
+    return true if !block_given? || blank?
+    !any?(&block)
+  end
 end
diff --git a/activesupport/test/core_ext/enumerable_test.rb b/activesupport/test/core_ext/enumerable_test.rb
index deb9b7544d..288ce14b2c 100644
--- a/activesupport/test/core_ext/enumerable_test.rb
+++ b/activesupport/test/core_ext/enumerable_test.rb
@@ -79,4 +79,14 @@ class EnumerableTests < Test::Unit::TestCase
     assert ![ 1, 2 ].many? {|x| x > 1 }
     assert [ 1, 2, 2 ].many? {|x| x > 1 }
   end
+
+  def test_none
+    assert [].none?
+    assert [ 1 ].none?
+
+    assert [].none? {|x| x > 1 }
+    assert ![ 2 ].none? {|x| x > 1 }
+    assert ![ 1, 2 ].none? {|x| x > 1 }
+    assert [ 1, 1 ].none? {|x| x > 1 }
+  end
 end