Eric Allam
13f750a18b
* v4: implement onCancel callbacks * chat example * Add changeset * A few improvements
41 lines
818 B
TypeScript
41 lines
818 B
TypeScript
export function assertExhaustive(x: never): never {
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throw new Error("Unexpected object: " + x);
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}
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export async function tryCatch<T, E = Error>(
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promise: Promise<T> | undefined
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): Promise<[null, T] | [E, null]> {
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if (!promise) {
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return [null, undefined as T];
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}
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try {
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const data = await promise;
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return [null, data];
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} catch (error) {
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return [error as E, null];
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}
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}
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export type Deferred<T> = {
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promise: Promise<T>;
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resolve: (value: T) => void;
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reject: (reason?: any) => void;
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};
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export function promiseWithResolvers<T>(): Deferred<T> {
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let resolve!: (value: T) => void;
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let reject!: (reason?: any) => void;
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const promise = new Promise<T>((_resolve, _reject) => {
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resolve = _resolve;
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reject = _reject;
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});
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return {
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promise,
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resolve,
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reject,
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};
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}
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