// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license. // // Adapted from Node.js. Copyright Joyent, Inc. and other Node contributors. // // Permission is hereby granted, free of charge, to any person obtaining a // copy of this software and associated documentation files (the // "Software"), to deal in the Software without restriction, including // without limitation the rights to use, copy, modify, merge, publish, // distribute, sublicense, and/or sell copies of the Software, and to permit // persons to whom the Software is furnished to do so, subject to the // following conditions: // // The above copyright notice and this permission notice shall be included // in all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE // USE OR OTHER DEALINGS IN THE SOFTWARE. // Hack: work around the following TypeScript error: // error: TS2345 [ERROR]: Argument of type 'typeof kCustomPromisifiedSymbol' // is not assignable to parameter of type 'typeof kCustomPromisifiedSymbol'. // assertStrictEquals(kCustomPromisifiedSymbol, promisify.custom); // ~~~~~~~~~~~~~~~~ declare const _CustomPromisifiedSymbol: unique symbol; declare const _CustomPromisifyArgsSymbol: unique symbol; declare let Symbol: SymbolConstructor; interface SymbolConstructor { for(key: "nodejs.util.promisify.custom"): typeof _CustomPromisifiedSymbol; for( key: "nodejs.util.promisify.customArgs" ): typeof _CustomPromisifyArgsSymbol; } // End hack. // In addition to being accessible through util.promisify.custom, // this symbol is registered globally and can be accessed in any environment as // Symbol.for('nodejs.util.promisify.custom'). const kCustomPromisifiedSymbol = Symbol.for("nodejs.util.promisify.custom"); // This is an internal Node symbol used by functions returning multiple // arguments, e.g. ['bytesRead', 'buffer'] for fs.read(). const kCustomPromisifyArgsSymbol = Symbol.for( "nodejs.util.promisify.customArgs" ); class NodeInvalidArgTypeError extends TypeError { public code = "ERR_INVALID_ARG_TYPE"; constructor(argumentName: string, type: string, received: unknown) { super( `The "${argumentName}" argument must be of type ${type}. Received ${typeof received}` ); } } export function promisify(original: Function): Function { if (typeof original !== "function") throw new NodeInvalidArgTypeError("original", "Function", original); // @ts-ignore TypeScript (as of 3.7) does not support indexing namespaces by symbol if (original[kCustomPromisifiedSymbol]) { // @ts-ignore TypeScript (as of 3.7) does not support indexing namespaces by symbol const fn = original[kCustomPromisifiedSymbol]; if (typeof fn !== "function") { throw new NodeInvalidArgTypeError( "util.promisify.custom", "Function", fn ); } return Object.defineProperty(fn, kCustomPromisifiedSymbol, { value: fn, enumerable: false, writable: false, configurable: true, }); } // Names to create an object from in case the callback receives multiple // arguments, e.g. ['bytesRead', 'buffer'] for fs.read. // @ts-ignore TypeScript (as of 3.7) does not support indexing namespaces by symbol const argumentNames = original[kCustomPromisifyArgsSymbol]; function fn(...args: unknown[]): Promise { return new Promise((resolve, reject) => { // @ts-ignore: 'this' implicitly has type 'any' because it does not have a type annotation original.call(this, ...args, (err: Error, ...values: unknown[]) => { if (err) { return reject(err); } if (argumentNames !== undefined && values.length > 1) { const obj = {}; for (let i = 0; i < argumentNames.length; i++) { // @ts-ignore TypeScript obj[argumentNames[i]] = values[i]; } resolve(obj); } else { resolve(values[0]); } }); }); } Object.setPrototypeOf(fn, Object.getPrototypeOf(original)); Object.defineProperty(fn, kCustomPromisifiedSymbol, { value: fn, enumerable: false, writable: false, configurable: true, }); return Object.defineProperties( fn, Object.getOwnPropertyDescriptors(original) ); } promisify.custom = kCustomPromisifiedSymbol;