Serialize and deserialize gradients to primitives

Author: zeevallin

lib/gradient/map.rb

@@ -3,6 +3,12 @@ class Map
 
     attr_reader :points, :locations
 
+    class << self
+      def deserialize(points=[])
+        new(points.map { |point| Gradient::Point.deserialize(*point) })
+      end
+    end
+
     def initialize(*points)
       @points = points.flatten.sort
       @locations = @points.map { |point| point.location }
@@ -17,5 +23,13 @@ def to_css(**args)
       @css_printer.css(**args)
     end
 
+    def serialize
+      @points.map(&:serialize)
+    end
+
+    def as_json(json={})
+      serialize
+    end
+
   end
 end

lib/gradient/point.rb

@@ -3,6 +3,20 @@ class Point
 
     attr_reader :location, :color, :opacity
 
+    class << self
+      def deserialize(location, color_type, color_values, opacity)
+        self.new(location, color_from(color_type, color_values), opacity)
+      end
+
+      private def color_from(color_type, color_values)
+        case color_type
+        when "rgb" then Color::RGB.new(*color_values)
+        else
+          raise NotImplementedError.new("#{string} is not a valid color type")
+        end
+      end
+    end
+
     def initialize(location, color, opacity)
       @location, @color, @opacity = location, color, opacity
     end
@@ -15,5 +29,20 @@ def <=>(other)
       self.location <=> other.location
     end
 
+    def serialize
+      [location, "rgb", [color.red.round, color.green.round, color.blue.round], opacity]
+    end
+
+    def as_json(json={})
+      serialize
+    end
+
+    def ==(other)
+      unless other.kind_of?(Gradient::Point)
+        raise ArgumentError.new("cannot compare Point with #{ other.class } using `=='")
+      end
+      location == other.location && color == other.color && opacity == other.opacity
+    end
+
   end
 end

spec/gradient/map_spec.rb

@@ -1,12 +1,12 @@
 RSpec.describe Gradient::Map do
 
-  describe "#initialize" do
+  let(:left_blue) { Gradient::Point.new(0, Color::RGB.new(0, 0, 255), 1) }
+  let(:middle_green) { Gradient::Point.new(0.5, Color::RGB.new(0, 255, 0), 1) }
+  let(:right_red) { Gradient::Point.new(1, Color::RGB.new(255, 0, 0), 1) }
 
-    let(:left_blue) { Gradient::Point.new(0, Color::RGB.new(0, 0, 255), 1) }
-    let(:middle_green) { Gradient::Point.new(0.5, Color::RGB.new(0, 255, 0), 1) }
-    let(:right_red) { Gradient::Point.new(1, Color::RGB.new(255, 0, 0), 1) }
+  subject(:map) { Gradient::Map.new(middle_green, left_blue, right_red) }
 
-    let(:map) { Gradient::Map.new(middle_green, left_blue, right_red) }
+  describe "#initialize" do
 
     it "sorts the points" do
       expect(map.points[0]).to eq left_blue
@@ -20,4 +20,40 @@
 
   end
 
+  describe ".deserialize" do
+    it "returns a point with the right attributes" do
+      deserialized_map = described_class.deserialize([
+        [0, "rgb", [0, 0, 255], 1],
+        [0.5, "rgb", [0, 255, 0], 1],
+        [1, "rgb", [255, 0, 0], 1]
+      ])
+      expect(deserialized_map.points[0].opacity).to eq 1
+      expect(deserialized_map.points[0].location).to eq 0
+      expect(deserialized_map.points[1].opacity).to eq 1
+      expect(deserialized_map.points[1].location).to eq 0.5
+      expect(deserialized_map.points[2].opacity).to eq 1
+      expect(deserialized_map.points[2].location).to eq 1
+    end
+  end
+
+  describe "#serialize" do
+    it "returns an array with the points as nested hashes" do
+      expect(map.serialize).to eq([
+        [0, "rgb", [0, 0, 255], 1],
+        [0.5, "rgb", [0, 255, 0], 1],
+        [1, "rgb", [255, 0, 0], 1]
+      ])
+    end
+  end
+
+  describe "#as_json" do
+    it "returns an array with the points as nested hashes" do
+      expect(map.as_json({})).to eq([
+        [0, "rgb", [0, 0, 255], 1],
+        [0.5, "rgb", [0, 255, 0], 1],
+        [1, "rgb", [255, 0, 0], 1]
+      ])
+    end
+  end
+
 end

spec/gradient/point_spec.rb

@@ -0,0 +1,24 @@
+RSpec.describe Gradient::Point do
+
+  describe ".deserialize" do
+    it "returns a point based on the provided array of values" do
+      point = Gradient::Point.deserialize(0.5, "rgb", [0, 255, 0], 1)
+      expect(point).to eq Gradient::Point.new(0.5, Color::RGB.new(0, 255, 0), 1)
+    end
+  end
+
+  describe "#serialize" do
+    it "returns an array with the color values" do
+      point = Gradient::Point.new(0.5, Color::RGB.new(0, 255, 0), 1)
+      expect(point.serialize).to eq([0.5, "rgb", [0, 255, 0], 1])
+    end
+  end
+
+  describe "#as_json" do
+    it "returns an array with the color values" do
+      point = Gradient::Point.new(0.5, Color::RGB.new(0, 255, 0), 1)
+      expect(point.as_json({})).to eq([0.5, "rgb", [0, 255, 0], 1])
+    end
+  end
+
+end