Merge pull request rails#54481 from etiennebarrie/json-coder

Use JSON::Coder when available

Author: byroot

Gemfile.lock

@@ -313,7 +313,7 @@ GEM
     jmespath (1.6.2)
     jsbundling-rails (1.3.1)
       railties (>= 6.0.0)
-    json (2.9.1)
+    json (2.10.0)
     jwt (2.10.1)
       base64
     kamal (2.4.0)

activesupport/lib/active_support/core_ext/string/output_safety.rb

@@ -139,6 +139,10 @@ def to_s
       self
     end
 
+    def as_json
+      to_str
+    end
+
     def to_param
       to_str
     end

activesupport/lib/active_support/json/encoding.rb

@@ -97,6 +97,51 @@ def stringify(jsonified)
           end
       end
 
+      if defined?(::JSON::Coder)
+        class JSONGemCoderEncoder # :nodoc:
+          JSON_NATIVE_TYPES = [Hash, Array, Float, String, Symbol, Integer, NilClass, TrueClass, FalseClass].freeze
+          CODER = ::JSON::Coder.new do |value|
+            json_value = value.as_json
+            # Handle objects returning self from as_json
+            if json_value.equal?(value)
+              next ::JSON::Fragment.new(::JSON.generate(json_value))
+            end
+            # Handle objects not returning JSON-native types from as_json
+            count = 5
+            until JSON_NATIVE_TYPES.include?(json_value.class)
+              raise SystemStackError if count == 0
+              json_value = json_value.as_json
+              count -= 1
+            end
+            json_value
+          end
+
+
+          def initialize(options = nil)
+            @options = options ? options.dup.freeze : {}.freeze
+          end
+
+          # Encode the given object into a JSON string
+          def encode(value)
+            value = value.as_json(@options) unless @options.empty?
+
+            json = CODER.dump(value)
+
+            # Rails does more escaping than the JSON gem natively does (we
+            # escape \u2028 and \u2029 and optionally >, <, & to work around
+            # certain browser problems).
+            if @options.fetch(:escape_html_entities, Encoding.escape_html_entities_in_json)
+              json.gsub!(">", '\u003e')
+              json.gsub!("<", '\u003c')
+              json.gsub!("&", '\u0026')
+            end
+            json.gsub!("\u2028", '\u2028')
+            json.gsub!("\u2029", '\u2029')
+            json
+          end
+        end
+      end
+
       class << self
         # If true, use ISO 8601 format for dates and times. Otherwise, fall back
         # to the Active Support legacy format.
@@ -126,7 +171,12 @@ def encode_without_options(value) # :nodoc:
 
       self.use_standard_json_time_format = true
       self.escape_html_entities_in_json  = true
-      self.json_encoder = JSONGemEncoder
+      self.json_encoder =
+        if defined?(::JSON::Coder)
+          JSONGemCoderEncoder
+        else
+          JSONGemEncoder
+        end
       self.time_precision = 3
     end
   end

activesupport/test/json/encoding_test.rb

@@ -484,6 +484,33 @@ def test_to_json_works_on_io_objects
     assert_equal STDOUT.to_s.to_json, STDOUT.to_json
   end
 
+  class AsJSONLoop
+    def initialize(count)
+      @count = count
+    end
+
+    def as_json
+      if @count > 0
+        @count -= 1
+        dup
+      else
+        self
+      end
+    end
+  end
+
+  def test_as_json_infinite_loop
+    assert_raise SystemStackError do
+      AsJSONLoop.new(Float::INFINITY).to_json
+    end
+  end
+
+  def test_as_json_too_recursive
+    assert_raise SystemStackError do
+      AsJSONLoop.new(20).to_json
+    end
+  end
+
   private
     def object_keys(json_object)
       json_object[1..-2].scan(/([^{}:,\s]+):/).flatten.sort
@@ -504,3 +531,16 @@ def with_time_precision(value)
       ActiveSupport::JSON::Encoding.time_precision = old_value
     end
 end
+
+if defined?(::JSON::Coder)
+  class OldJSONEncodingTest < TestJSONEncoding
+    setup do
+      @json_encoder = ActiveSupport::JSON::Encoding.json_encoder
+      ActiveSupport::JSON::Encoding.json_encoder = ActiveSupport::JSON::Encoding::JSONGemEncoder
+    end
+
+    teardown do
+      ActiveSupport::JSON::Encoding.json_encoder = @json_encoder
+    end
+  end
+end