feat: add useSpring hook

src/index.ts

@@ -26,6 +26,7 @@ export * from "./use-motion";
 export * from "./use-mount-effect";
 export * from "./use-mouse";
 export * from "./use-previous";
+export * from "./use-spring";
 export * from "./use-tagged";
 export * from "./use-throttle-callback";
 export * from "./use-throttle-effect";

src/use-spring/README.md

@@ -0,0 +1,38 @@
+## 🪝 `useSpring`
+
+```ts
+function useSpring<T extends MotionGoal>(goal: T | Binding<T>, options?: SpringOptions): Binding<T>
+```
+
+Applies spring animations to the given value, and updates the goal with the latest value on every re-render. Returns a binding that updates with the Motion.
+
+### 📕 Parameters
+
+-   `goal` - The goal of the motor.
+-   `options` - Options for the spring (or a spring config).
+
+### 📗 Returns
+
+-   A binding of the motor's value.
+
+### 📘 Example
+
+A button that fades in and out when hovered.
+
+```tsx
+function Button() {
+	const [springValue, setSpringValue] = useBinding(0)
+	const hover = useSpring(springValue, config.spring.stiff);
+
+	return (
+		<textbutton
+			Event={{
+				MouseEnter: () => setSpringValue(1),
+				MouseLeave: () => setSpringValue(0),
+			}}
+			Size={new UDim2(0, 100, 0, 100)}
+			BackgroundTransparency={hover.map((t) => lerp(0.8, 0.5, t))}
+		/>
+	);
+}
+```

src/use-spring/index.ts

@@ -0,0 +1 @@
+export * from "./use-spring";

src/use-spring/use-spring.spec.ts

@@ -0,0 +1,15 @@
+/// <reference types="@rbxts/testez/globals" />
+
+import { renderHook } from "../utils/testez";
+import { useSpring } from "./use-spring";
+
+export = () => {
+	it("should return a binding", () => {
+		const { result, unmount } = renderHook(() => useSpring(0));
+
+		expect(result.current.getValue()).to.be.a("number");
+		expect(result.current.getValue()).to.equal(0);
+
+		unmount();
+	});
+};

src/use-spring/use-spring.ts

@@ -0,0 +1,25 @@
+import type { Binding } from "@rbxts/react";
+import { useRef } from "@rbxts/react";
+import type { MotionGoal, SpringOptions } from "@rbxts/ripple";
+import { useMotion } from "../use-motion";
+import { getBindingValue } from "../utils/binding";
+import { useEventListener } from "../use-event-listener";
+import { RunService } from "@rbxts/services";
+
+export function useSpring(goal: number | Binding<number>, options?: SpringOptions): Binding<number>;
+export function useSpring<T extends MotionGoal>(goal: T | Binding<T>, options?: SpringOptions): Binding<T>;
+export function useSpring(goal: MotionGoal | Binding<MotionGoal>, options?: SpringOptions) {
+	const [binding, motion] = useMotion(getBindingValue(goal));
+	const previousValue = useRef(getBindingValue(goal));
+
+	useEventListener(RunService.Heartbeat, () => {
+		const currentValue = getBindingValue(goal);
+
+		if (currentValue !== previousValue.current) {
+			previousValue.current = currentValue;
+			motion.spring(currentValue, options);
+		}
+	});
+
+	return binding;
+}