test: add benchmarks, dev mode

src/__tests__/benchmarks/atom.bench.luau

@@ -0,0 +1,53 @@
+-- This file is for use by Benchmarker
+-- https://boatbomber.itch.io/benchmarker
+
+local Package = game:GetService("ReplicatedStorage").Packages.charm
+
+local atom = require(Package.atom)
+local derive = require(Package.derive)
+
+return {
+	ParameterGenerator = function()
+		return atom({ count = 0 })
+	end,
+
+	Functions = {
+		atom = function(_, source: any)
+			for _ = 1, 500 do
+				source({ count = math.random(1, 2) })
+			end
+		end,
+
+		derived = function(_, source: any)
+			derive(source, function(state)
+				return { count = 2 * state.count }
+			end)
+			for _ = 1, 500 do
+				source({ count = math.random(1, 2) })
+			end
+		end,
+
+		derived_memo = function(_, source: any)
+			source:memo(function(previous, current)
+				return previous.count == current.count
+			end)
+			derive(source, function(state)
+				return { count = 2 * state.count }
+			end)
+			for _ = 1, 500 do
+				source({ count = math.random(1, 2) })
+			end
+		end,
+
+		derived_writable = function(_, source: any)
+			local derived = derive(source, function(state)
+				return { count = 2 * state.count }
+			end):writable(function(update)
+				source({ count = 0.5 * update.count })
+			end)
+			for _ = 1, 500 do
+				derived({ count = 2 * math.random(1, 2) })
+			end
+		end,
+	},
+}