src/utils/FileUtils.ts

   1 import fs from 'node:fs';
   2
   3 import chalk from 'chalk';
   4
   5 import { Utils, logger } from './internal';
   6 import type { EmptyObject, FileType, HandleErrorParams, JsonType } from '../types';
   7
   8 export class FileUtils {
   9   private constructor() {
  10     // This is intentional
  11   }
  12
  13   public static watchJsonFile<T extends JsonType>(
  14     file: string,
  15     fileType: FileType,
  16     logPrefix: string,
  17     refreshedVariable?: T,
  18     listener: fs.WatchListener<string> = (event, filename) => {
  19       if (Utils.isNotEmptyString(filename) && event === 'change') {
  20         try {
  21           logger.debug(`${logPrefix} ${fileType} file ${file} have changed, reload`);
  22           refreshedVariable && (refreshedVariable = JSON.parse(fs.readFileSync(file, 'utf8')) as T);
  23         } catch (error) {
  24           FileUtils.handleFileException(file, fileType, error as NodeJS.ErrnoException, logPrefix, {
  25             throwError: false,
  26           });
  27         }
  28       }
  29     }
  30   ): fs.FSWatcher | undefined {
  31     if (Utils.isNotEmptyString(file)) {
  32       try {
  33         return fs.watch(file, listener);
  34       } catch (error) {
  35         FileUtils.handleFileException(file, fileType, error as NodeJS.ErrnoException, logPrefix, {
  36           throwError: false,
  37         });
  38       }
  39     } else {
  40       logger.info(`${logPrefix} No ${fileType} file to watch given. Not monitoring its changes`);
  41     }
  42   }
  43
  44   public static handleFileException(
  45     file: string,
  46     fileType: FileType,
  47     error: NodeJS.ErrnoException,
  48     logPrefix: string,
  49     params: HandleErrorParams<EmptyObject> = { throwError: true, consoleOut: false }
  50   ): void {
  51     const prefix = Utils.isNotEmptyString(logPrefix) ? `${logPrefix} ` : '';
  52     let logMsg: string;
  53     switch (error.code) {
  54       case 'ENOENT':
  55         logMsg = `${fileType} file ${file} not found:`;
  56         break;
  57       case 'EEXIST':
  58         logMsg = `${fileType} file ${file} already exists:`;
  59         break;
  60       case 'EACCES':
  61         logMsg = `${fileType} file ${file} access denied:`;
  62         break;
  63       default:
  64         logMsg = `${fileType} file ${file} error:`;
  65     }
  66     if (params?.consoleOut) {
  67       logMsg = `${logMsg} `;
  68       console.warn(`${chalk.green(prefix)}${chalk.yellow(logMsg)}`, error);
  69     } else {
  70       logger.warn(`${prefix}${logMsg}`, error);
  71     }
  72     if (params?.throwError) {
  73       throw error;
  74     }
  75   }
  76 }