diff options
| -rw-r--r-- | activesupport/lib/active_support/core_ext/hash/slice.rb | 5 | ||||
| -rw-r--r-- | activesupport/test/core_ext/hash_ext_test.rb | 21 |
2 files changed, 26 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/core_ext/hash/slice.rb b/activesupport/lib/active_support/core_ext/hash/slice.rb index be4dec6e53..3f14470f36 100644 --- a/activesupport/lib/active_support/core_ext/hash/slice.rb +++ b/activesupport/lib/active_support/core_ext/hash/slice.rb @@ -9,6 +9,11 @@ module ActiveSupport #:nodoc: # end # # search(options.slice(:mass, :velocity, :time)) + # + # If you have an array of keys you want to limit to, you should splat them: + # + # valid_keys = [:mass, :velocity, :time] + # search(options.slice(*valid_keys)) module Slice # Returns a new hash with only the given keys. def slice(*keys) diff --git a/activesupport/test/core_ext/hash_ext_test.rb b/activesupport/test/core_ext/hash_ext_test.rb index 2ab7681a8a..fc8ed45358 100644 --- a/activesupport/test/core_ext/hash_ext_test.rb +++ b/activesupport/test/core_ext/hash_ext_test.rb @@ -292,6 +292,27 @@ class HashExtTest < Test::Unit::TestCase assert_equal expected, original end + def test_slice_with_an_array_key + original = { :a => 'x', :b => 'y', :c => 10, [:a, :b] => "an array key" } + expected = { [:a, :b] => "an array key", :c => 10 } + + # Should return a new hash with only the given keys when given an array key. + assert_equal expected, original.slice([:a, :b], :c) + assert_not_equal expected, original + + # Should replace the hash with only the given keys when given an array key. + assert_equal expected, original.slice!([:a, :b], :c) + assert_equal expected, original + end + + def test_slice_with_splatted_keys + original = { :a => 'x', :b => 'y', :c => 10, [:a, :b] => "an array key" } + expected = { :a => 'x', :b => "y" } + + # Should grab each of the splatted keys. + assert_equal expected, original.slice(*[:a, :b]) + end + def test_indifferent_slice original = { :a => 'x', :b => 'y', :c => 10 }.with_indifferent_access expected = { :a => 'x', :b => 'y' }.with_indifferent_access |