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Merge pull request #7007 from Mik-die/hash_extract

make Hash#extract! more symmetric with Hash#slice
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2 parents 3e75369 + a4b1196 commit e68b97a4b65787711e50aa1565b4dd0077a00d6d @rafaelfranca rafaelfranca committed Oct 12, 2012
@@ -1,5 +1,16 @@
## Rails 4.0.0 (unreleased) ##
+* Hash#extract! returns only those keys that present in the receiver.
+
+ {:a => 1, :b => 2}.extract!(:a, :x) # => {:a => 1}
+
+ *Mikhail Dieterle*
+
+* Hash#extract! returns the same subclass, that the receiver is. I.e.
+ HashWithIndifferentAccess#extract! returns HashWithIndifferentAccess instance.
+
+ *Mikhail Dieterle*
+
* Optimize ActiveSupport::Cache::Entry to reduce memory and processing overhead. *Brian Durand*
* Tests tag the Rails log with the current test class and test case:
@@ -32,9 +32,9 @@ def slice!(*keys)
# Removes and returns the key/value pairs matching the given keys.
#
- # { a: 1, b: 2, c: 3, d: 4 }.extract!(:a, :b)
- # # => {:a => 1, :b => 2}
+ # { a: 1, b: 2, c: 3, d: 4 }.extract!(:a, :b) # => { a: 1, b: 2 }
+ # { a: 1, b: 2 }.extract!(:a, :x) # => { a: 1 }
def extract!(*keys)
- keys.each_with_object({}) { |key, result| result[key] = delete(key) }
+ keys.each_with_object(self.class.new) { |key, result| result[key] = delete(key) if has_key?(key) }
end
end
@@ -723,8 +723,32 @@ def test_indifferent_slice_access_with_symbols
def test_extract
original = {:a => 1, :b => 2, :c => 3, :d => 4}
expected = {:a => 1, :b => 2}
+ remaining = {:c => 3, :d => 4}
- assert_equal expected, original.extract!(:a, :b)
+ assert_equal expected, original.extract!(:a, :b, :x)
+ assert_equal remaining, original
+ end
+
+ def test_extract_nils
+ original = {:a => nil, :b => nil}
+ expected = {:a => nil}
+ extracted = original.extract!(:a, :x)
+
+ assert_equal expected, extracted
+ assert_equal nil, extracted[:a]
+ assert_equal nil, extracted[:x]
+ end
+
+ def test_indifferent_extract
+ original = {:a => 1, 'b' => 2, :c => 3, 'd' => 4}.with_indifferent_access
+ expected = {:a => 1, :b => 2}.with_indifferent_access
+ remaining = {:c => 3, :d => 4}.with_indifferent_access
+
+ [['a', 'b'], [:a, :b]].each do |keys|
+ copy = original.dup
+ assert_equal expected, copy.extract!(*keys)
+ assert_equal remaining, copy
+ end
end
def test_except
@@ -2867,8 +2867,16 @@ The method `extract!` removes and returns the key/value pairs matching the given
```ruby
hash = {:a => 1, :b => 2}
-rest = hash.extract!(:a) # => {:a => 1}
-hash # => {:b => 2}
+rest = hash.extract!(:a, :x) # => {:a => 1} # non-existing keys are ignored
+hash # => {:b => 2}
+```
+
+The method `extract!` returns the same subclass of Hash, that the receiver is.
+
+```ruby
+hash = {:a => 1, :b => 2}.with_indifferent_access
+rest = hash.extract!(:a).class
+# => ActiveSupport::HashWithIndifferentAccess
```
NOTE: Defined in `active_support/core_ext/hash/slice.rb`.

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