47 lines
1.6 KiB
TypeScript
47 lines
1.6 KiB
TypeScript
/*
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* Vencord, a modification for Discord's desktop app
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* Copyright (c) 2022 Vendicated and contributors
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <https://www.gnu.org/licenses/>.
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*/
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import type { LiteralUnion } from "type-fest";
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/**
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* Wait for a property to be defined on the target, then call the callback with
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* the value
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* @param target Object
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* @param property Property to be defined
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* @param callback Callback
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*
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* @example onceDefined(window, "webpackChunkdiscord_app", wpInstance => wpInstance.push(...));
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*/
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export function onceDefined<T extends object, P extends LiteralUnion<keyof T, PropertyKey>>(
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target: T, property: P, callback: (v: P extends keyof T ? T[P] : any) => void
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): void {
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const propertyAsAny = property as any;
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if (property in target)
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return void callback(target[propertyAsAny]);
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Object.defineProperty(target, property, {
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set(v) {
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delete target[propertyAsAny];
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target[propertyAsAny] = v;
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callback(v);
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},
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configurable: true,
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enumerable: false
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});
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}
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