1 files changed, 134 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/json/encoding.rb b/activesupport/lib/active_support/json/encoding.rb
new file mode 100644
index 0000000000..de1b8ac8cf
--- /dev/null
+++ b/activesupport/lib/active_support/json/encoding.rb
@@ -0,0 +1,134 @@
+# frozen_string_literal: true
+
+require "active_support/core_ext/object/json"
+require "active_support/core_ext/module/delegation"
+
+module ActiveSupport
+  class << self
+    delegate :use_standard_json_time_format, :use_standard_json_time_format=,
+      :time_precision, :time_precision=,
+      :escape_html_entities_in_json, :escape_html_entities_in_json=,
+      :json_encoder, :json_encoder=,
+      to: :'ActiveSupport::JSON::Encoding'
+  end
+
+  module JSON
+    # Dumps objects in JSON (JavaScript Object Notation).
+    # See http://www.json.org for more info.
+    #
+    #   ActiveSupport::JSON.encode({ team: 'rails', players: '36' })
+    #   # => "{\"team\":\"rails\",\"players\":\"36\"}"
+    def self.encode(value, options = nil)
+      Encoding.json_encoder.new(options).encode(value)
+    end
+
+    module Encoding #:nodoc:
+      class JSONGemEncoder #:nodoc:
+        attr_reader :options
+
+        def initialize(options = nil)
+          @options = options || {}
+        end
+
+        # Encode the given object into a JSON string
+        def encode(value)
+          stringify jsonify value.as_json(options.dup)
+        end
+
+        private
+          # Rails does more escaping than the JSON gem natively does (we
+          # escape \u2028 and \u2029 and optionally >, <, & to work around
+          # certain browser problems).
+          ESCAPED_CHARS = {
+            "\u2028" => '\u2028',
+            "\u2029" => '\u2029',
+            ">"      => '\u003e',
+            "<"      => '\u003c',
+            "&"      => '\u0026',
+            }
+
+          ESCAPE_REGEX_WITH_HTML_ENTITIES = /[\u2028\u2029><&]/u
+          ESCAPE_REGEX_WITHOUT_HTML_ENTITIES = /[\u2028\u2029]/u
+
+          # This class wraps all the strings we see and does the extra escaping
+          class EscapedString < String #:nodoc:
+            def to_json(*)
+              if Encoding.escape_html_entities_in_json
+                s = super
+                s.gsub! ESCAPE_REGEX_WITH_HTML_ENTITIES, ESCAPED_CHARS
+                s
+              else
+                s = super
+                s.gsub! ESCAPE_REGEX_WITHOUT_HTML_ENTITIES, ESCAPED_CHARS
+                s
+              end
+            end
+
+            def to_s
+              self
+            end
+          end
+
+          # Mark these as private so we don't leak encoding-specific constructs
+          private_constant :ESCAPED_CHARS, :ESCAPE_REGEX_WITH_HTML_ENTITIES,
+            :ESCAPE_REGEX_WITHOUT_HTML_ENTITIES, :EscapedString
+
+          # Convert an object into a "JSON-ready" representation composed of
+          # primitives like Hash, Array, String, Numeric,
+          # and +true+/+false+/+nil+.
+          # Recursively calls #as_json to the object to recursively build a
+          # fully JSON-ready object.
+          #
+          # This allows developers to implement #as_json without having to
+          # worry about what base types of objects they are allowed to return
+          # or having to remember to call #as_json recursively.
+          #
+          # Note: the +options+ hash passed to +object.to_json+ is only passed
+          # to +object.as_json+, not any of this method's recursive +#as_json+
+          # calls.
+          def jsonify(value)
+            case value
+            when String
+              EscapedString.new(value)
+            when Numeric, NilClass, TrueClass, FalseClass
+              value.as_json
+            when Hash
+              Hash[value.map { |k, v| [jsonify(k), jsonify(v)] }]
+            when Array
+              value.map { |v| jsonify(v) }
+            else
+              jsonify value.as_json
+            end
+          end
+
+          # Encode a "jsonified" Ruby data structure using the JSON gem
+          def stringify(jsonified)
+            ::JSON.generate(jsonified, quirks_mode: true, max_nesting: false)
+          end
+      end
+
+      class << self
+        # If true, use ISO 8601 format for dates and times. Otherwise, fall back
+        # to the Active Support legacy format.
+        attr_accessor :use_standard_json_time_format
+
+        # If true, encode >, <, & as escaped unicode sequences (e.g. > as \u003e)
+        # as a safety measure.
+        attr_accessor :escape_html_entities_in_json
+
+        # Sets the precision of encoded time values.
+        # Defaults to 3 (equivalent to millisecond precision)
+        attr_accessor :time_precision
+
+        # Sets the encoder used by Rails to encode Ruby objects into JSON strings
+        # in +Object#to_json+ and +ActiveSupport::JSON.encode+.
+        attr_accessor :json_encoder
+      end
+
+      self.use_standard_json_time_format = true
+      self.escape_html_entities_in_json  = true
+      self.json_encoder = JSONGemEncoder
+      self.time_precision = 3
+    end
+  end
+end