61 lines
1.7 KiB
TypeScript
61 lines
1.7 KiB
TypeScript
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import { React } from "../webpack";
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/**
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* Makes a lazy function. On first call, the value is computed.
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* On subsequent calls, the same computed value will be returned
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* @param factory Factory function
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*/
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export function lazy<T>(factory: () => T): () => T {
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let cache: T;
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return () => {
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return cache ?? (cache = factory());
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};
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}
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/**
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* Await a promise
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* @param factory Factory
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* @param fallbackValue The fallback value that will be used until the promise resolved
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* @returns A state that will either be null or the result of the promise
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*/
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export function useAwaiter<T>(factory: () => Promise<T>, fallbackValue: T | null = null): T | null {
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const [res, setRes] = React.useState<T | null>(fallbackValue);
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React.useEffect(() => {
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factory().then(setRes);
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}, []);
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return res;
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}
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/**
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* A lazy component. The factory method is called on first render. For example useful
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* for const Component = LazyComponent(() => findByDisplayName("...").default)
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* @param factory Function returning a Component
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* @returns Result of factory function
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*/
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export function LazyComponent<T = any>(factory: () => React.ComponentType<T>) {
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return (props: T) => {
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const Component = React.useMemo(factory, []);
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return <Component {...props} />;
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};
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}
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/**
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* Recursively merges defaults into an object and returns the same object
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* @param obj Object
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* @param defaults Defaults
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* @returns obj
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*/
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export function mergeDefaults<T>(obj: T, defaults: T): T {
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for (const key in defaults) {
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const v = defaults[key];
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if (typeof v === "object" && !Array.isArray(v)) {
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obj[key] ??= {} as any;
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mergeDefaults(obj[key], v);
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} else {
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obj[key] ??= v;
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}
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}
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return obj;
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}
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