code-server/lib/vscode/extensions/github-authentication/src/common/utils.ts
2021-03-11 10:27:10 -07:00

101 lines
2.7 KiB
TypeScript

/*---------------------------------------------------------------------------------------------
* Copyright (c) Microsoft Corporation. All rights reserved.
* Licensed under the MIT License. See License.txt in the project root for license information.
*--------------------------------------------------------------------------------------------*/
import { EventEmitter, Event, Disposable } from 'vscode';
export function filterEvent<T>(event: Event<T>, filter: (e: T) => boolean): Event<T> {
return (listener, thisArgs = null, disposables?) => event(e => filter(e) && listener.call(thisArgs, e), null, disposables);
}
export function onceEvent<T>(event: Event<T>): Event<T> {
return (listener, thisArgs = null, disposables?) => {
const result = event(e => {
result.dispose();
return listener.call(thisArgs, e);
}, null, disposables);
return result;
};
}
export interface PromiseAdapter<T, U> {
(
value: T,
resolve:
(value: U | PromiseLike<U>) => void,
reject:
(reason: any) => void
): any;
}
const passthrough = (value: any, resolve: (value?: any) => void) => resolve(value);
/**
* Return a promise that resolves with the next emitted event, or with some future
* event as decided by an adapter.
*
* If specified, the adapter is a function that will be called with
* `(event, resolve, reject)`. It will be called once per event until it resolves or
* rejects.
*
* The default adapter is the passthrough function `(value, resolve) => resolve(value)`.
*
* @param event the event
* @param adapter controls resolution of the returned promise
* @returns a promise that resolves or rejects as specified by the adapter
*/
export function promiseFromEvent<T, U>(
event: Event<T>,
adapter: PromiseAdapter<T, U> = passthrough): { promise: Promise<U>, cancel: EventEmitter<void> } {
let subscription: Disposable;
let cancel = new EventEmitter<void>();
return {
promise: new Promise<U>((resolve, reject) => {
cancel.event(_ => reject());
subscription = event((value: T) => {
try {
Promise.resolve(adapter(value, resolve, reject))
.catch(reject);
} catch (error) {
reject(error);
}
});
}).then(
(result: U) => {
subscription.dispose();
return result;
},
error => {
subscription.dispose();
throw error;
}
),
cancel
};
}
export function arrayEquals<T>(one: ReadonlyArray<T> | undefined, other: ReadonlyArray<T> | undefined, itemEquals: (a: T, b: T) => boolean = (a, b) => a === b): boolean {
if (one === other) {
return true;
}
if (!one || !other) {
return false;
}
if (one.length !== other.length) {
return false;
}
for (let i = 0, len = one.length; i < len; i++) {
if (!itemEquals(one[i], other[i])) {
return false;
}
}
return true;
}