removes Array#random_element and backports Array#sample from Ruby 1.9, thanks...

removes Array#random_element and backports Array#sample from Ruby 1.9, thanks to Marc-Andre Lafortune

activerecord/test/cases/associations/eager_load_nested_include_test.rb

@@ -17,7 +17,7 @@ def remember; self.class.remembered << self; end
 
   module ClassMethods
     def remembered; @@remembered ||= []; end
-    def random_element; @@remembered.random_element; end
+    def sample; @@remembered.sample; end
   end
 end
 
@@ -79,14 +79,14 @@ def generate_test_object_graphs
       [Circle, Square, Triangle, NonPolyOne, NonPolyTwo].map(&:create!)
     end
     1.upto(NUM_SIMPLE_OBJS) do
-      PaintColor.create!(:non_poly_one_id => NonPolyOne.random_element.id)
-      PaintTexture.create!(:non_poly_two_id => NonPolyTwo.random_element.id)
+      PaintColor.create!(:non_poly_one_id => NonPolyOne.sample.id)
+      PaintTexture.create!(:non_poly_two_id => NonPolyTwo.sample.id)
     end
     1.upto(NUM_SHAPE_EXPRESSIONS) do
-      shape_type = [Circle, Square, Triangle].random_element
-      paint_type = [PaintColor, PaintTexture].random_element
-      ShapeExpression.create!(:shape_type => shape_type.to_s, :shape_id => shape_type.random_element.id,
-                              :paint_type => paint_type.to_s, :paint_id => paint_type.random_element.id)
+      shape_type = [Circle, Square, Triangle].sample
+      paint_type = [PaintColor, PaintTexture].sample
+      ShapeExpression.create!(:shape_type => shape_type.to_s, :shape_id => shape_type.sample.id,
+                              :paint_type => paint_type.to_s, :paint_id => paint_type.sample.id)
     end
   end
 

activerecord/test/cases/named_scope_test.rb

@@ -301,7 +301,7 @@ def test_find_all_should_behave_like_select
   end
 
   def test_rand_should_select_a_random_object_from_proxy
-    assert_kind_of Topic, Topic.approved.random_element
+    assert_kind_of Topic, Topic.approved.sample
   end
 
   def test_should_use_where_in_query_for_named_scope

activesupport/CHANGELOG

@@ -4,7 +4,7 @@
 
 * Ruby 1.9: support UTF-8 case folding.  #4595 [Norman Clarke]
 
-* Renames Array#rand -> Array#random_element. [Santiago Pastorino, Rizwan Reza]
+* Removes Array#rand and backports Array#sample from Ruby 1.9, thanks to Marc-Andre Lafortune. [fxn]
 
 * Ruby 1.9: Renames last_(month|year) to prev_(month|year) in Date and Time. [fxn]
 

activesupport/lib/active_support/core_ext/array/random_access.rb

 class Array
-  # Returns a random element from the array.
-  def random_element
-    self[Kernel.rand(length)]
-  end
+  # Backport of Array#sample based on Marc-Andre Lafortune's http://github.com/marcandre/backports/
+  def sample(n=nil)
+    return self[Kernel.rand(size)] if n.nil?
+    n = n.to_int
+  rescue Exception => e
+    raise TypeError, "Coercion error: #{n.inspect}.to_int => Integer failed:\n(#{e.message})"
+  else
+    raise TypeError, "Coercion error: obj.to_int did NOT return an Integer (was #{n.class})" unless n.kind_of? Integer
+    raise ArgumentError, "negative array size" if n < 0
+    n = size if n > size
+    result = Array.new(self)
+    n.times do |i|
+      r = i + Kernel.rand(size - i)
+      result[i], result[r] = result[r], result[i]
+    end
+    result[n..size] = []
+    result
+  end unless method_defined? :sample
 end
\ No newline at end of file

activesupport/test/core_ext/array_ext_test.rb

@@ -359,14 +359,30 @@ def test_uniq_by!
 end
 
 class ArrayExtRandomTests < ActiveSupport::TestCase
-  def test_random_element_from_array
-    assert_nil [].random_element
-
-    Kernel.expects(:rand).with(1).returns(0)
-    assert_equal 'x', ['x'].random_element
+  def test_sample_from_array
+    assert_nil [].sample
+    assert_equal [], [].sample(5)
+    assert_equal 42, [42].sample
+    assert_equal [42], [42].sample(5)
+
+    a = [:foo, :bar, 42]
+    s = a.sample(2)
+    assert_equal 2, s.size
+    assert_equal 1, (a-s).size
+    assert_equal [], a-(0..20).sum{a.sample(2)}
+  
+    o = Object.new
+    def o.to_int; 1; end
+    assert_equal [0], [0].sample(o)
+  
+    o = Object.new
+    assert_raises(TypeError) { [0].sample(o) }
+    
+    o = Object.new
+    def o.to_int; ''; end
+    assert_raises(TypeError) { [0].sample(o) }
 
-    Kernel.expects(:rand).with(3).returns(1)
-    assert_equal 2, [1, 2, 3].random_element
+    assert_raises(ArgumentError) { [0].sample(-7) }
   end
 end
 

railties/guides/source/3_0_release_notes.textile

@@ -512,6 +512,7 @@ These are the main changes in Active Support:
 * Active Support no longer provides vendored versions of "TZInfo":http://tzinfo.rubyforge.org/, "Memcache Client":http://deveiate.org/projects/RMemCache/ and "Builder":http://builder.rubyforge.org/, these are all included as dependencies and installed via the <tt>bundle install</tt> command.
 * Safe buffers are implemented in <tt>ActiveSupport::SafeBuffer</tt>.
 * Added <tt>Array.uniq_by</tt> and <tt>Array.uniq_by!</tt>.
+* Removed <tt>Array#rand</tt> and backported <tt>Array#sample</tt> from Ruby 1.9.
 * Fixed bug on +TimeZone.seconds_to_utc_offset+ returning wrong value.
 * Added <tt>ActiveSupport::Notifications</tt> middleware.
 * <tt>ActiveSupport.use_standard_json_time_format</tt> now defaults to true.

railties/guides/source/active_support_core_extensions.textile

@@ -1927,13 +1927,23 @@ Similarly, +from+ returns the tail from the element at the passed index on:
 
 The methods +second+, +third+, +fourth+, and +fifth+ return the corresponding element (+first+ is builtin). Thanks to social wisdom and positive constructiveness all around, +forty_two+ is also available.
 
-You can pick a random element with +random_element+:
+NOTE: Defined in +active_support/core_ext/array/access.rb+.
+
+h4. Random Access
+
+Active Support backports +sample+ from Ruby 1.9:
+
+You can pick a random element with +sample+:
 
 <ruby>
-shape_type = [Circle, Square, Triangle].random_element
+shape_type = [Circle, Square, Triangle].sample
+# => Square, for example
+
+shape_types = [Circle, Square, Triangle].sample(2)
+# => [Triangle, Circle], for example
 </ruby>
 
-NOTE: Defined in +active_support/core_ext/array/access.rb+.
+NOTE: Defined in +active_support/core_ext/array/random_access.rb+.
 
 h4. Options Extraction
 

railties/test/application/initializers/frameworks_test.rb

@@ -47,7 +47,7 @@ def setup
     test "if there's no config.active_support.bare, all of ActiveSupport is required" do
       use_frameworks []
       require "#{app_path}/config/environment"
-      assert_nothing_raised { [1,2,3].random_element }
+      assert_nothing_raised { [1,2,3].sample }
     end
 
     test "config.active_support.bare does not require all of ActiveSupport" do
@@ -57,7 +57,7 @@ def setup
 
       Dir.chdir("#{app_path}/app") do
         require "#{app_path}/config/environment"
-        assert_raises(NoMethodError) { [1,2,3].random_element }
+        assert_raises(NoMethodError) { [1,2,3].sample }
       end
     end