Add Clock#as_json and Clock#to_json.

Author: samuel-williams-shopify

lib/async/clock.rb

@@ -36,6 +36,9 @@ def initialize(total = 0)
 			@started = nil
 		end
 
+		# @returns [Numeric | Nil] The time when the clock was started, or nil if not started.
+		attr :started
+		
 		# Start measuring a duration.
 		def start!
 			@started ||= Clock.now
@@ -70,5 +73,22 @@ def reset!
 				@started = Clock.now
 			end
 		end
+		
+		# Convert the clock to a JSON-compatible hash.
+		#
+		# @returns [Hash] The JSON-compatible hash.
+		def as_json(...)
+			{
+				started: self.started,
+				total: self.total,
+			}
+		end
+		
+		# Convert the clock to a JSON string.
+		#
+		# @returns [String] The JSON string.
+		def to_json(...)
+			self.as_json.to_json(...)
+		end
 	end
 end

test/async/clock.rb

@@ -146,4 +146,83 @@
 			expect(duration).to be >= 0
 		end
 	end
+	
+	with "#as_json" do
+		it "returns a hash with started and total keys" do
+			json = clock.as_json
+			
+			expect(json).to be_a Hash
+			expect(json).to have_keys(:started, :total)
+		end
+		
+		it "includes nil started when not started" do
+			json = clock.as_json
+			
+			expect(json[:started]).to be_nil
+			expect(json[:total]).to be == 0
+		end
+		
+		it "includes started time when started" do
+			clock.start!
+			json = clock.as_json
+			
+			expect(json[:started]).to be_a Numeric
+			expect(json[:started]).to be > 0
+			expect(json[:total]).to be >= 0
+		end
+		
+		it "includes accumulated total" do
+			clock.start!
+			sleep(0.001)
+			clock.stop!
+			json = clock.as_json
+			
+			expect(json[:started]).to be_nil
+			expect(json[:total]).to be > 0
+		end
+		
+		it "includes total with initial duration" do
+			clock = subject.new(5.0)
+			json = clock.as_json
+			
+			expect(json[:total]).to be == 5.0
+		end
+	end
+	
+	with "#to_json" do
+		it "returns a JSON string" do
+			json_string = clock.to_json
+			
+			expect(json_string).to be_a String
+		end
+		
+		it "can be parsed back to a hash" do
+			clock.start!
+			sleep(0.001)
+			clock.stop!
+			
+			json_string = clock.to_json
+			parsed = JSON.parse(json_string)
+			
+			expect(parsed).to be_a Hash
+			expect(parsed).to have_keys("started", "total")
+			expect(parsed["total"]).to be > 0
+		end
+		
+		it "preserves nil started value" do
+			json_string = clock.to_json
+			parsed = JSON.parse(json_string)
+			
+			expect(parsed["started"]).to be_nil
+		end
+		
+		it "preserves started time when running" do
+			clock.start!
+			json_string = clock.to_json
+			parsed = JSON.parse(json_string)
+			
+			expect(parsed["started"]).to be_a Numeric
+			expect(parsed["started"]).to be > 0
+		end
+	end
 end