chore: housekeeping

packages/react-charm/default.project.json

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+{
+	"name": "ReactCharm",
+	"tree": {
+		"$path": "src"
+	}
+}

packages/react-charm/src/init.luau

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+local Charm = require(script.Parent.Charm)
+local React = require(script.Parent.React)
+
+local effect = Charm.effect
+local useBinding = React.useBinding
+local useEffect = React.useEffect
+local useState = React.useState
+local useMemo = React.useMemo
+
+--- A hook that subscribes to changes in the given atom or selector. The
+--- component is re-rendered whenever the state changes.
+---
+--- If the `dependencies` array is provided, the effect is re-created whenever
+--- the dependencies change. Otherwise, the subscription is created once when
+--- the component is mounted.
+---
+--- @param selector The atom or selector to subscribe to.
+--- @param dependencies An array of values that the subscription depends on.
+--- @return The current state.
+local function useAtom<State>(selector: () -> State, dependencies: { any }?): State
+	local state, setState = useState(selector)
+
+	useEffect(function()
+		return effect(function()
+			setState(selector())
+		end)
+	end, dependencies or {})
+
+	return state
+end
+
+--- A hook that subscribes to changes in the given atom or selector. Returns
+--- a binding that updates when the state changes.
+---
+--- If the `dependencies` array is provided, the effect is re-created whenever
+--- the dependencies change. Otherwise, the subscription is created once when
+--- the component is mounted.
+---
+--- @param selector The atom or selector to subscribe to.
+--- @param dependencies An array of values that the subscription depends on.
+--- @return A binding that stores the current state.
+local function useAtomBinding<State>(selector: () -> State, dependencies: { any }?)
+	local initialState = useMemo(selector, {})
+	local binding, setBinding = useBinding(initialState)
+
+	useEffect(function()
+		return effect(function()
+			setBinding(selector())
+		end)
+	end, dependencies or {})
+
+	return binding
+end
+
+return {
+	useAtom = useAtom,
+	useAtomBinding = useAtomBinding,
+}

packages/react-charm/tests/helpers/renderHook.luau

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+local ReplicatedStorage = game:GetService("ReplicatedStorage")
+
+_G.__ROACT_17_MOCK_SCHEDULER__ = true
+
+local React = require(ReplicatedStorage.Packages.React)
+local ReactRoblox = require(ReplicatedStorage.Packages.ReactRoblox)
+
+type RenderedHook<Props, Result> = {
+	result: Result,
+	rerender: (Props?) -> (),
+	unmount: () -> (),
+}
+
+local function renderHook<Props, Result>(callback: (Props) -> Result, props: Props?): RenderedHook<Props, Result>
+	local root = ReactRoblox.createLegacyRoot(Instance.new("Folder"))
+	local hook = {}
+
+	local function Component(props)
+		hook.result = callback(props)
+	end
+
+	function hook.rerender(newProps)
+		props = newProps or props
+		ReactRoblox.act(function()
+			root:render(React.createElement(Component, props))
+		end)
+	end
+
+	function hook.unmount()
+		ReactRoblox.act(function()
+			root:unmount()
+		end)
+	end
+
+	ReactRoblox.act(function()
+		hook.rerender(props)
+	end)
+
+	return hook
+end
+
+return renderHook

packages/react-charm/tests/spec.luau

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+local ServerScriptService = game:GetService("ServerScriptService")
+
+local suite = require(ServerScriptService.Tests.suite)
+
+suite.describe("react-charm", function()
+	suite.describe("useAtom", function()
+		require("./useAtom.spec")
+	end)
+	suite.describe("useAtomBinding", function()
+		require("./useAtomBinding.spec")
+	end)
+end)
+
+return {}

packages/react-charm/tests/useAtom.spec.luau

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+local ReplicatedStorage = game:GetService("ReplicatedStorage")
+local ServerScriptService = game:GetService("ServerScriptService")
+
+local Charm = require(ReplicatedStorage.Packages.Charm)
+local ReactCharm = require(ReplicatedStorage.Packages.ReactCharm)
+local renderHook = require(script.Parent.helpers.renderHook)
+local suite = require(ServerScriptService.Tests.suite)
+
+local atom = Charm.atom
+local useAtom = ReactCharm.useAtom
+local test = suite.test
+
+test("tracks atom state", function()
+	local state = atom(0)
+	local hook = renderHook(function()
+		return useAtom(state)
+	end)
+	assert(hook.result == 0, "should return 0")
+	state(1)
+	assert(hook.result == 1, "should return 1")
+end)
+
+test("accepts a selector", function()
+	local state = atom(0)
+	local hook = renderHook(function()
+		return useAtom(function()
+			return 2 * state()
+		end)
+	end)
+	assert(hook.result == 0, "should return 0")
+	state(1)
+	assert(hook.result == 2, "should return 2")
+end)
+
+test("tracks dependencies", function()
+	local state = atom(0)
+	local hook = renderHook(function()
+		return useAtom(state, { state })
+	end)
+	assert(hook.result == 0, "should return 0")
+	state(1)
+	assert(hook.result == 1, "should return 1")
+	state = atom(0)
+	hook.rerender()
+	assert(hook.result == 0, "should return 0")
+	state(1)
+	assert(hook.result == 1, "should return 1")
+end)
+
+return {}

packages/react-charm/tests/useAtomBinding.spec.luau

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+local ReplicatedStorage = game:GetService("ReplicatedStorage")
+local ServerScriptService = game:GetService("ServerScriptService")
+
+local Charm = require(ReplicatedStorage.Packages.Charm)
+local ReactCharm = require(ReplicatedStorage.Packages.ReactCharm)
+local renderHook = require(script.Parent.helpers.renderHook)
+local suite = require(ServerScriptService.Tests.suite)
+
+local atom = Charm.atom
+local useAtomBinding = ReactCharm.useAtomBinding
+local test = suite.test
+
+test("tracks atom state", function()
+	local state = atom(0)
+	local hook = renderHook(function()
+		return useAtomBinding(state)
+	end)
+	assert(hook.result:getValue() == 0, "should return 0")
+	state(1)
+	assert(hook.result:getValue() == 1, "should return 1")
+end)
+
+test("accepts a selector", function()
+	local state = atom(0)
+	local hook = renderHook(function()
+		return useAtomBinding(function()
+			return 2 * state()
+		end)
+	end)
+	assert(hook.result:getValue() == 0, "should return 0")
+	state(1)
+	assert(hook.result:getValue() == 2, "should return 2")
+end)
+
+test("tracks dependencies", function()
+	local state = atom(0)
+	local hook = renderHook(function()
+		return useAtomBinding(state, { state })
+	end)
+	assert(hook.result:getValue() == 0, "should return 0")
+	state(1)
+	assert(hook.result:getValue() == 1, "should return 1")
+	state = atom(0)
+	hook.rerender()
+	assert(hook.result:getValue() == 0, "should return 0")
+	state(1)
+	assert(hook.result:getValue() == 1, "should return 1")
+end)
+
+return {}

packages/react-charm/wally.toml

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+[package]
+name = "littensy/react-charm"
+version = "0.3.0"
+registry = "https://github.com/UpliftGames/wally-index"
+realm = "shared"
+exclude = ["tests"]
+
+[dependencies]
+Charm = "littensy/charm@^0.10"
+React = "jsdotlua/react@^17"