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// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
export interface ExistsOptions {  /**   * When `true`, will check if the path is readable by the user as well.   * @default {false}   */  isReadable?: boolean;  /**   * When `true`, will check if the path is a directory as well.   * Directory symlinks are included.   * @default {false}   */  isDirectory?: boolean;  /**   * When `true`, will check if the path is a file as well.   * File symlinks are included.   * @default {false}   */  isFile?: boolean;}
/** * Test whether or not the given path exists by checking with the file system. Please consider to check if the path is readable and either a file or a directory by providing additional `options`: * * ```ts * import { exists } from "https://deno.land/std@$STD_VERSION/fs/mod.ts"; * const isReadableDir = await exists("./foo", { *   isReadable: true, *   isDirectory: true * }); * const isReadableFile = await exists("./bar", { *   isReadable: true, *   isFile: true * }); * ``` * * Note: Do not use this function if performing a check before another operation on that file. Doing so creates a race condition. Instead, perform the actual file operation directly. * * Bad: * ```ts * import { exists } from "https://deno.land/std@$STD_VERSION/fs/mod.ts"; * * if (await exists("./foo")) { *   await Deno.remove("./foo"); * } * ``` * * Good: * ```ts * // Notice no use of exists * try { *   await Deno.remove("./foo", { recursive: true }); * } catch (error) { *   if (!(error instanceof Deno.errors.NotFound)) { *     throw error; *   } *   // Do nothing... * } * ``` * @see https://en.wikipedia.org/wiki/Time-of-check_to_time-of-use */export async function exists(  path: string | URL,  options?: ExistsOptions,): Promise<boolean> {  try {    const stat = await Deno.stat(path);    if (      options &&      (options.isReadable || options.isDirectory || options.isFile)    ) {      if (options.isDirectory && options.isFile) {        throw new TypeError(          "ExistsOptions.options.isDirectory and ExistsOptions.options.isFile must not be true together.",        );      }      if (        (options.isDirectory && !stat.isDirectory) ||        (options.isFile && !stat.isFile)      ) {        return false;      }      if (options.isReadable) {        if (stat.mode === null) {          return true; // Exclusive on Non-POSIX systems        }        if (Deno.uid() === stat.uid) {          return (stat.mode & 0o400) === 0o400; // User is owner and can read?        } else if (Deno.gid() === stat.gid) {          return (stat.mode & 0o040) === 0o040; // User group is owner and can read?        }        return (stat.mode & 0o004) === 0o004; // Others can read?      }    }    return true;  } catch (error) {    if (error instanceof Deno.errors.NotFound) {      return false;    }    if (error instanceof Deno.errors.PermissionDenied) {      if (        (await Deno.permissions.query({ name: "read", path })).state ===          "granted"      ) {        // --allow-read not missing        return !options?.isReadable; // PermissionDenied was raised by file system, so the item exists, but can't be read      }    }    throw error;  }}
/** * Test whether or not the given path exists by checking with the file system. Please consider to check if the path is readable and either a file or a directory by providing additional `options`: * * ```ts * import { existsSync } from "https://deno.land/std@$STD_VERSION/fs/mod.ts"; * const isReadableDir = existsSync("./foo", { *   isReadable: true, *   isDirectory: true * }); * const isReadableFile = existsSync("./bar", { *   isReadable: true, *   isFile: true * }); * ``` * * Note: do not use this function if performing a check before another operation on that file. Doing so creates a race condition. Instead, perform the actual file operation directly. * * Bad: * ```ts * import { existsSync } from "https://deno.land/std@$STD_VERSION/fs/mod.ts"; * * if (existsSync("./foo")) { *   Deno.removeSync("./foo"); * } * ``` * * Good: * ```ts * // Notice no use of existsSync * try { *   Deno.removeSync("./foo", { recursive: true }); * } catch (error) { *   if (!(error instanceof Deno.errors.NotFound)) { *     throw error; *   } *   // Do nothing... * } * ``` * @see https://en.wikipedia.org/wiki/Time-of-check_to_time-of-use */export function existsSync(  path: string | URL,  options?: ExistsOptions,): boolean {  try {    const stat = Deno.statSync(path);    if (      options &&      (options.isReadable || options.isDirectory || options.isFile)    ) {      if (options.isDirectory && options.isFile) {        throw new TypeError(          "ExistsOptions.options.isDirectory and ExistsOptions.options.isFile must not be true together.",        );      }      if (        (options.isDirectory && !stat.isDirectory) ||        (options.isFile && !stat.isFile)      ) {        return false;      }      if (options.isReadable) {        if (stat.mode === null) {          return true; // Exclusive on Non-POSIX systems        }        if (Deno.uid() === stat.uid) {          return (stat.mode & 0o400) === 0o400; // User is owner and can read?        } else if (Deno.gid() === stat.gid) {          return (stat.mode & 0o040) === 0o040; // User group is owner and can read?        }        return (stat.mode & 0o004) === 0o004; // Others can read?      }    }    return true;  } catch (error) {    if (error instanceof Deno.errors.NotFound) {      return false;    }    if (error instanceof Deno.errors.PermissionDenied) {      if (        Deno.permissions.querySync({ name: "read", path }).state === "granted"      ) {        // --allow-read not missing        return !options?.isReadable; // PermissionDenied was raised by file system, so the item exists, but can't be read      }    }    throw error;  }}