src/utils/FileUtils.ts

   1 import { type FSWatcher, readFileSync, watch, type WatchListener } from 'node:fs'
   2
   3 import type { FileType, JsonType } from '../types/index.js'
   4 import { handleFileException } from './ErrorUtils.js'
   5 import { logger } from './Logger.js'
   6 import { isNotEmptyString } from './Utils.js'
   7
   8 export const watchJsonFile = <T extends JsonType>(
   9   file: string,
  10   fileType: FileType,
  11   logPrefix: string,
  12   refreshedVariable?: T,
  13   listener: WatchListener<string> = (event, filename) => {
  14     if (isNotEmptyString(filename) && event === 'change') {
  15       try {
  16         logger.debug(`${logPrefix} ${fileType} file ${file} have changed, reload`)
  17         refreshedVariable != null &&
  18           (refreshedVariable = JSON.parse(readFileSync(file, 'utf8')) as T)
  19       } catch (error) {
  20         handleFileException(file, fileType, error as NodeJS.ErrnoException, logPrefix, {
  21           throwError: false
  22         })
  23       }
  24     }
  25   }
  26 ): FSWatcher | undefined => {
  27   if (isNotEmptyString(file)) {
  28     try {
  29       return watch(file, listener)
  30     } catch (error) {
  31       handleFileException(file, fileType, error as NodeJS.ErrnoException, logPrefix, {
  32         throwError: false
  33       })
  34     }
  35   } else {
  36     logger.info(`${logPrefix} No ${fileType} file to watch given. Not monitoring its changes`)
  37   }
  38 }