import * as fs from "fs"; import * as path from "path"; import * as util from "util"; import { isCli, buildDir } from "./constants"; // tslint:disable:no-any const nativeFs = (global).nativeFs as typeof fs || {}; const oldAccess = fs.access; const existsWithinBinary = (path: fs.PathLike): Promise => { return new Promise((resolve): void => { if (typeof path === "number") { if (path < 0) { return resolve(true); } } oldAccess(path, fs.constants.F_OK, (err) => { const exists = !err; const es = fs.existsSync(path); const res = !exists && es; resolve(res); }); }); }; export const fillFs = (): void => { /** * Refer to https://github.com/nexe/nexe/blob/master/src/fs/patch.ts * For impls */ if (!isCli) { throw new Error("Should not fill FS when not in CLI"); } interface FD { readonly path: string; position: number; } let lastFd = Number.MIN_SAFE_INTEGER; const fds = new Map(); const replaceNative = (propertyName: T, func: (callOld: () => void, ...args: any[]) => any, customPromisify?: (...args: any[]) => Promise): void => { const oldFunc = (fs)[propertyName]; fs[propertyName] = (...args: any[]): any => { try { return func(() => { return oldFunc(...args); }, ...args); } catch (ex) { return oldFunc(...args); } }; if (customPromisify) { (fs[propertyName])[util.promisify.custom] = (...args: any[]): any => { return customPromisify(...args).catch((ex) => { throw ex; }); }; } }; replaceNative("access", (callNative, path, mode, callback) => { existsWithinBinary(path).then((exists) => { if (!exists) { return callNative(); } return callback(); }); }); replaceNative("exists", (callOld, path, callback) => { existsWithinBinary(path).then((exists) => { if (exists) { return callback(true); } return callOld(); }); }, (path) => new Promise((res): void => fs.exists(path, res))); replaceNative("open", (callOld, path: fs.PathLike, flags: string | Number, mode: any, callback: any) => { existsWithinBinary(path).then((exists) => { if (!exists) { return callOld(); } if (typeof mode === "function") { callback = mode; mode = undefined; } if (path === process.execPath) { return callOld(); } const fd = lastFd++; fds.set(fd, { path: path.toString(), position: 0, }); callback(undefined, fd); }); }); replaceNative("close", (callOld, fd: number, callback) => { if (!fds.has(fd)) { return callOld(); } fds.delete(fd); callback(); }); replaceNative("read", (callOld, fd: number, buffer: Buffer, offset: number, length: number, position: number | null, callback?: (err: NodeJS.ErrnoException, bytesRead: number, buffer: Buffer) => void) => { if (!fds.has(fd)) { return callOld(); } const fileDesc = fds.get(fd)!; return fs.readFile(fileDesc.path, (err, rb) => { if (err) { return callOld(); } rb = rb.slice(position || fileDesc.position); const sliced = rb.slice(0, length); if (position === null) { fileDesc.position += sliced.byteLength; } buffer.set(sliced, offset); if (callback) { callback(undefined!, sliced.byteLength, buffer); } }); }, (fd: number, buffer: Buffer, offset: number, length: number, position: number | null): Promise<{ bytesRead: number; buffer: Buffer; }> => { return new Promise((res, rej): void => { fs.read(fd, buffer, offset, length, position, (err, bytesRead, buffer) => { if (err) { return rej(err); } res({ bytesRead, buffer, }); }); }); }); replaceNative("readdir", (callOld, directory: string, callback: (err: NodeJS.ErrnoException, paths: string[]) => void) => { const relative = path.relative(directory, buildDir!); if (relative.startsWith("..")) { return callOld(); } return nativeFs.readdir(directory, callback); }); };