Add error handling to JSON schemas file reading
[e-mobility-charging-stations-simulator.git] / src / utils / FileUtils.ts
1 import fs from 'node:fs';
2
3 import chalk from 'chalk';
4
5 import logger from './Logger';
6 import Utils from './Utils';
7 import type { EmptyObject } from '../types/EmptyObject';
8 import type { HandleErrorParams } from '../types/Error';
9 import type { FileType } from '../types/FileType';
10 import type { JsonType } from '../types/JsonType';
11
12 export default class FileUtils {
13 private constructor() {
14 // This is intentional
15 }
16
17 public static watchJsonFile<T extends JsonType>(
18 logPrefix: string,
19 fileType: FileType,
20 file: string,
21 refreshedVariable?: T,
22 listener: fs.WatchListener<string> = (event, filename) => {
23 if (!Utils.isEmptyString(filename) && event === 'change') {
24 try {
25 logger.debug(`${logPrefix} ${fileType} file ${file} have changed, reload`);
26 refreshedVariable && (refreshedVariable = JSON.parse(fs.readFileSync(file, 'utf8')) as T);
27 } catch (error) {
28 FileUtils.handleFileException(logPrefix, fileType, file, error as NodeJS.ErrnoException, {
29 throwError: false,
30 });
31 }
32 }
33 }
34 ): fs.FSWatcher | undefined {
35 if (!Utils.isEmptyString(file)) {
36 try {
37 return fs.watch(file, listener);
38 } catch (error) {
39 FileUtils.handleFileException(logPrefix, fileType, file, error as NodeJS.ErrnoException, {
40 throwError: false,
41 });
42 }
43 } else {
44 logger.info(`${logPrefix} No ${fileType} file to watch given. Not monitoring its changes`);
45 }
46 }
47
48 public static handleFileException(
49 logPrefix: string,
50 fileType: FileType,
51 file: string,
52 error: NodeJS.ErrnoException,
53 params: HandleErrorParams<EmptyObject> = { throwError: true, consoleOut: false }
54 ): void {
55 const prefix = !Utils.isEmptyString(logPrefix) ? `${logPrefix} ` : '';
56 let logMsg: string;
57 switch (error.code) {
58 case 'ENOENT':
59 logMsg = `${fileType} file ${file} not found:`;
60 break;
61 case 'EEXIST':
62 logMsg = `${fileType} file ${file} already exists:`;
63 break;
64 case 'EACCES':
65 logMsg = `${fileType} file ${file} access denied:`;
66 break;
67 default:
68 logMsg = `${fileType} file ${file} error:`;
69 }
70 if (params?.consoleOut) {
71 logMsg = `${logMsg} `;
72 console.warn(`${chalk.green(prefix)}${chalk.yellow(logMsg)}`, error);
73 } else {
74 logger.warn(`${prefix}${logMsg}`, error);
75 }
76 if (params?.throwError) {
77 throw error;
78 }
79 }
80 }