class Hash # Returns a new hash with all keys converted using the +block+ operation. # # hash = { name: 'Rob', age: '28' } # # hash.transform_keys { |key| key.to_s.upcase } # => {"NAME"=>"Rob", "AGE"=>"28"} # # If you do not provide a +block+, it will return an Enumerator # for chaining with other methods: # # hash.transform_keys.with_index { |k, i| [k, i].join } # => {"name0"=>"Rob", "age1"=>"28"} def transform_keys return enum_for(:transform_keys) { size } unless block_given? result = {} each_key do |key| result[yield(key)] = self[key] end result end # Destructively converts all keys using the +block+ operations. # Same as +transform_keys+ but modifies +self+. def transform_keys! return enum_for(:transform_keys!) { size } unless block_given? keys.each do |key| self[yield(key)] = delete(key) end self end # Returns a new hash with all keys converted to strings. # # hash = { name: 'Rob', age: '28' } # # hash.stringify_keys # # => {"name"=>"Rob", "age"=>"28"} def stringify_keys transform_keys(&:to_s) end # Destructively converts all keys to strings. Same as # +stringify_keys+, but modifies +self+. def stringify_keys! transform_keys!(&:to_s) end # Returns a new hash with all keys converted to symbols, as long as # they respond to +to_sym+. # # hash = { 'name' => 'Rob', 'age' => '28' } # # hash.symbolize_keys # # => {:name=>"Rob", :age=>"28"} def symbolize_keys transform_keys { |key| key.to_sym rescue key } end alias_method :to_options, :symbolize_keys # Destructively converts all keys to symbols, as long as they respond # to +to_sym+. Same as +symbolize_keys+, but modifies +self+. def symbolize_keys! transform_keys! { |key| key.to_sym rescue key } end alias_method :to_options!, :symbolize_keys! # Validates all keys in a hash match *valid_keys, raising # +ArgumentError+ on a mismatch. # # Note that keys are treated differently than HashWithIndifferentAccess, # meaning that string and symbol keys will not match. # # { name: 'Rob', years: '28' }.assert_valid_keys(:name, :age) # => raises "ArgumentError: Unknown key: :years. Valid keys are: :name, :age" # { name: 'Rob', age: '28' }.assert_valid_keys('name', 'age') # => raises "ArgumentError: Unknown key: :name. Valid keys are: 'name', 'age'" # { name: 'Rob', age: '28' }.assert_valid_keys(:name, :age) # => passes, raises nothing def assert_valid_keys(*valid_keys) valid_keys.flatten! each_key do |k| unless valid_keys.include?(k) raise ArgumentError.new("Unknown key: #{k.inspect}. Valid keys are: #{valid_keys.map(&:inspect).join(', ')}") end end end # Returns a new hash with all keys converted by the block operation. # This includes the keys from the root hash and from all # nested hashes and arrays. # # hash = { person: { name: 'Rob', age: '28' } } # # hash.deep_transform_keys{ |key| key.to_s.upcase } # # => {"PERSON"=>{"NAME"=>"Rob", "AGE"=>"28"}} def deep_transform_keys(&block) _deep_transform_keys_in_object(self, &block) end # Destructively converts all keys by using the block operation. # This includes the keys from the root hash and from all # nested hashes and arrays. def deep_transform_keys!(&block) _deep_transform_keys_in_object!(self, &block) end # Returns a new hash with all keys converted to strings. # This includes the keys from the root hash and from all # nested hashes and arrays. # # hash = { person: { name: 'Rob', age: '28' } } # # hash.deep_stringify_keys # # => {"person"=>{"name"=>"Rob", "age"=>"28"}} def deep_stringify_keys deep_transform_keys(&:to_s) end # Destructively converts all keys to strings. # This includes the keys from the root hash and from all # nested hashes and arrays. def deep_stringify_keys! deep_transform_keys!(&:to_s) end # Returns a new hash with all keys converted to symbols, as long as # they respond to +to_sym+. This includes the keys from the root hash # and from all nested hashes and arrays. # # hash = { 'person' => { 'name' => 'Rob', 'age' => '28' } } # # hash.deep_symbolize_keys # # => {:person=>{:name=>"Rob", :age=>"28"}} def deep_symbolize_keys deep_transform_keys { |key| key.to_sym rescue key } end # Destructively converts all keys to symbols, as long as they respond # to +to_sym+. This includes the keys from the root hash and from all # nested hashes and arrays. def deep_symbolize_keys! deep_transform_keys! { |key| key.to_sym rescue key } end private # support methods for deep transforming nested hashes and arrays def _deep_transform_keys_in_object(object, &block) case object when Hash object.each_with_object({}) do |(key, value), result| result[yield(key)] = _deep_transform_keys_in_object(value, &block) end when Array object.map { |e| _deep_transform_keys_in_object(e, &block) } else object end end def _deep_transform_keys_in_object!(object, &block) case object when Hash object.keys.each do |key| value = object.delete(key) object[yield(key)] = _deep_transform_keys_in_object!(value, &block) end object when Array object.map! { |e| _deep_transform_keys_in_object!(e, &block) } else object end end end