chore: audit usages of bind()

packages/core/data/mutation-sensitive-array/index.ts

@@ -1,57 +1,49 @@
 /**
  * A lightweight extension of Array that calls listeners just before any
  * mutations. This allows you to lazily take a clone of an array (i.e. use the
- * array as-is until such time as it mutates).
+ * array as-is until such time as it mutates). In other worse, "copy on write".
  *
  * This could equally be implemented by adding pre-mutation events into
  * ObservableArray, but the whole point is to be as lightweight as possible as
  * its entire purpose is to be used for performance-sensitive tasks.
  */
 export class MutationSensitiveArray<T> extends Array<T> {
-	onMutation: (() => void) | null = null;
-
-	private invalidate(): void {
-		if (this.onMutation) {
-			this.onMutation();
-		}
-	}
-
-	// Override each mutating Array method so that it invalidates our snapshot.
+	beforeMutation: (() => void) | null = null;
 
 	pop(): T | undefined {
-		this.invalidate();
+		this.beforeMutation?.();
 		return super.pop();
 	}
 	push(...items: T[]): number {
-		this.invalidate();
+		this.beforeMutation?.();
 		return super.push(...items);
 	}
 	reverse(): T[] {
-		this.invalidate();
+		this.beforeMutation?.();
 		return super.reverse();
 	}
 	shift(): T | undefined {
-		this.invalidate();
+		this.beforeMutation?.();
 		return super.shift();
 	}
 	sort(compareFn?: (a: T, b: T) => number): this {
-		this.invalidate();
+		this.beforeMutation?.();
 		return super.sort(compareFn);
 	}
 	splice(start: number, deleteCount: number, ...rest: T[]): T[] {
-		this.invalidate();
+		this.beforeMutation?.();
 		return super.splice(start, deleteCount, ...rest);
 	}
 	unshift(...items: T[]): number {
-		this.invalidate();
+		this.beforeMutation?.();
 		return super.unshift(...items);
 	}
 	fill(value: T, start?: number, end?: number): this {
-		this.invalidate();
+		this.beforeMutation?.();
 		return super.fill(value, start, end);
 	}
 	copyWithin(target: number, start: number, end?: number): this {
-		this.invalidate();
+		this.beforeMutation?.();
 		return super.copyWithin(target, start, end);
 	}
 }