Memory leak in `ToastState` - dismissed toasts never cleaned up

[helciofranco]

It seems this package has a memory leak where dismissed toasts are never removed from the global state, causing the toasts array to grow indefinitely throughout the application's lifetime.

The Observer class in state.ts maintains a this.toasts array that accumulates every toast ever created, but never removes them when they are dismissed or closed.

The problem becomes significantly more severe when using custom JSX content.
Each toast object retains full React element trees with component instances, hooks, event handlers, and DOM references in this.toasts.

These never get garbage collected since the global array holds strong references, leading to exponentially higher memory usage compared to primitive title / description  strings.

Simple strings use ~1-5KB per toast; complex JSX can exceed 10-50KB each, causing gigabytes of leaks in long-running SPAs.
Example: Crypto Exchange.

• Relates to Toast DOM nodes are leaked #605 cc @Ducklett

---

Demo

1. addToast only appends more items

sonner/src/state.ts

Lines 42 to 45 in 45d8940

	addToast = (data: ToastT) => {
	this.publish(data);
	this.toasts = [...this.toasts, data];
	};

2. dismiss doesn't clean up the this.toasts array

sonner/src/state.ts

Lines 88 to 99 in 45d8940

	dismiss = (id?: number | string) => {
	if (id) {
	this.dismissedToasts.add(id);
	requestAnimationFrame(() => this.subscribers.forEach((subscriber) => subscriber({ id, dismiss: true })));
	} else {
	this.toasts.forEach((toast) => {
	this.subscribers.forEach((subscriber) => subscriber({ id: toast.id, dismiss: true }));
	});
	}
	return id;
	};

3. The dismissed toasts remain in this.toasts forever, only tracked separately in this.dismissedToasts Set.

4. The component state in index.tsx properly filters toasts

sonner/src/index.tsx

Line 560 in 45d8940

setActiveToasts((toasts) => toasts.filter((t) => t.id !== toast.id));

sonner/src/index.tsx

Line 652 in 45d8940

return toasts.filter(({ id }) => id !== toastToRemove.id);

However, the global ToastState.toasts in the Observer class is never cleaned up.

---

Proposed Solutions

1. Adding a maximum history size with LRU eviction
   OR
2. Adding a clearHistory() method
   OR
3. Adding cleanup logic to the dismiss method (this should be a little bit harder due to the animations)

[ljhljh127]

I've submitted a PR (#734) that adds a toast.clearHistory() method as one of the proposed solutions. It allows manual cleanup while preserving the existing history behavior.