debounced codemirror autocomplete

debounceAutocompletion.ts

export function debounceAutocompletion(
	language: Language,
	source: CompletionSource,
	wait: number = 500,
) {
	let currContext: CompletionContext;
	let cancel = () => {}; // no-op
	return [
		language.data.of({
			autocomplete: (context: CompletionContext) => {
				currContext = context; // Use latest context.
				cancel();
				return null;
			}
		}),
		language.data.of({
			autocomplete: (context: CompletionContext) => {
				currContext = context; // Use latest context.
				cancel();
				return new Promise(resolve => {
					const timeoutId = window.setTimeout(async () => {
						try {							
							const result = await source(currContext);
							resolve(result);
						} catch (error) {
							resolve(null);
						}
					}, wait);
					cancel = () => {
						clearTimeout(timeoutId);
						resolve(null);
					}
					context.addEventListener("abort", cancel);
				});
			}
		}),
	]
}