25 lines
1.1 KiB
TypeScript
25 lines
1.1 KiB
TypeScript
|
/**
|
||
|
|
* Wraps a metro lookup so it isn't run until first actually used, and retries on every call until
|
||
|
|
* it succeeds once (after which the result is cached forever). A plugin's top-level module code
|
||
|
|
* runs as soon as its bundle is required, which can be before Discord's own code has required an
|
||
|
|
* internal module it depends on - a one-shot findByX() at module scope can permanently cache
|
||
|
|
* undefined even though the real module becomes available moments later. Only meant for values
|
||
|
|
* used inside event handlers or plain (non-hook) render logic - wrapping something used as a
|
||
|
|
* React hook (e.g. passed to useContext) in this can violate the Rules of Hooks, since the
|
||
|
|
* resolved-or-not status is now allowed to change between renders of the same component instance.
|
||
|
|
*/
|
||
|
|
export function lazy<T>(resolve: () => T | null | undefined): () => T | undefined {
|
||
|
|
let cached: T | undefined;
|
||
|
|
let resolved = false;
|
||
|
|
|
||
|
|
return () => {
|
||
|
|
if (resolved) return cached;
|
||
|
|
const value = resolve();
|
||
|
|
if (value != null) {
|
||
|
|
cached = value;
|
||
|
|
resolved = true;
|
||
|
|
}
|
||
|
|
return value ?? undefined;
|
||
|
|
};
|
||
|
|
}
|