Extract ActiveSupport::TypedArray class to ensure an array is all of the same type [#673 state:resolved]

3 files changed, 83 insertions, 0 deletions

diff --git a/activesupport/lib/active_support.rb b/activesupport/lib/active_support.rb
index 1df911a3f2..51067e910e 100644
--- a/activesupport/lib/active_support.rb
+++ b/activesupport/lib/active_support.rb
@@ -39,6 +39,7 @@ require 'active_support/cache'
 require 'active_support/dependencies'
 require 'active_support/deprecation'
 
+require 'active_support/typed_array'
 require 'active_support/ordered_hash'
 require 'active_support/ordered_options'
 require 'active_support/option_merger'
diff --git a/activesupport/lib/active_support/typed_array.rb b/activesupport/lib/active_support/typed_array.rb
new file mode 100644
index 0000000000..1a4d8a8faf
--- /dev/null
+++ b/activesupport/lib/active_support/typed_array.rb
@@ -0,0 +1,31 @@
+module ActiveSupport
+  class TypedArray < Array
+    def self.type_cast(obj)
+      obj
+    end
+
+    def initialize(*args)
+      super(*args).map! { |obj| self.class.type_cast(obj) }
+    end
+
+    def <<(obj)
+      super(self.class.type_cast(obj))
+    end
+
+    def concat(array)
+      super(array.map! { |obj| self.class.type_cast(obj) })
+    end
+
+    def insert(index, obj)
+      super(index, self.class.type_cast(obj))
+    end
+
+    def push(*objs)
+      super(*objs.map { |obj| self.class.type_cast(obj) })
+    end
+
+    def unshift(*objs)
+      super(*objs.map { |obj| self.class.type_cast(obj) })
+    end
+  end
+end
diff --git a/activesupport/test/typed_array_test.rb b/activesupport/test/typed_array_test.rb
new file mode 100644
index 0000000000..023f3a1b84
--- /dev/null
+++ b/activesupport/test/typed_array_test.rb
@@ -0,0 +1,51 @@
+require 'abstract_unit'
+
+class TypedArrayTest < Test::Unit::TestCase
+  class StringArray < ActiveSupport::TypedArray
+    def self.type_cast(obj)
+      obj.to_s
+    end
+  end
+
+  def setup
+    @array = StringArray.new
+  end
+
+  def test_string_array_initialize
+    assert_equal ["1", "2", "3"], StringArray.new([1, "2", :"3"])
+  end
+
+  def test_string_array_append
+    @array << 1
+    @array << "2"
+    @array << :"3"
+    assert_equal ["1", "2", "3"], @array
+  end
+
+  def test_string_array_concat
+    @array.concat([1, "2"])
+    @array.concat([:"3"])
+    assert_equal ["1", "2", "3"], @array
+  end
+
+  def test_string_array_insert
+    @array.insert(0, 1)
+    @array.insert(1, "2")
+    @array.insert(2, :"3")
+    assert_equal ["1", "2", "3"], @array
+  end
+
+  def test_string_array_push
+    @array.push(1)
+    @array.push("2")
+    @array.push(:"3")
+    assert_equal ["1", "2", "3"], @array
+  end
+
+  def test_string_array_unshift
+    @array.unshift(:"3")
+    @array.unshift("2")
+    @array.unshift(1)
+    assert_equal ["1", "2", "3"], @array
+  end
+end