From f21e43c16a27a6746ef7ec9e50faf59df405d0fd Mon Sep 17 00:00:00 2001
From: louistiti <louis.grenard@gmail.com>
Date: Wed, 21 Sep 2022 20:43:50 +0800
Subject: [PATCH] refactor(server): date helper to singleton

---
 server/src/core/http-server/server.js |  4 +-
 server/src/helpers/date.ts            | 70 ++++++++++++++++-----------
 server/src/helpers/log.ts             |  4 +-
 test/unit/server/helpers/date.spec.js |  8 +--
 4 files changed, 52 insertions(+), 34 deletions(-)

diff --git a/server/src/core/http-server/server.js b/server/src/core/http-server/server.js
index f890484d..388a6067 100644
--- a/server/src/core/http-server/server.js
+++ b/server/src/core/http-server/server.js
@@ -27,7 +27,7 @@ import keyMidd from '@/core/http-server/plugins/key'
 import infoPlugin from '@/core/http-server/api/info'
 import downloadsPlugin from '@/core/http-server/api/downloads'
 import { LOG } from '@/helpers/log'
-import { getTimeZone } from '@/helpers/date'
+import { DATE } from '@/helpers/date'
 
 const server = {}
 
@@ -378,7 +378,7 @@ server.init = async () => {
   LOG.success(`The current env is ${process.env.LEON_NODE_ENV}`)
   LOG.success(`The current version is ${version}`)
 
-  LOG.success(`The current time zone is ${getTimeZone()}`)
+  LOG.success(`The current time zone is ${DATE.getTimeZone()}`)
 
   const sLogger = !HAS_LOGGER ? 'disabled' : 'enabled'
   LOG.success(`Collaborative logger ${sLogger}`)
diff --git a/server/src/helpers/date.ts b/server/src/helpers/date.ts
index 29efced9..ac4b0e58 100644
--- a/server/src/helpers/date.ts
+++ b/server/src/helpers/date.ts
@@ -8,34 +8,50 @@ import { LOG } from '@/helpers/log'
 dayjs.extend(utc)
 dayjs.extend(timezone)
 
-/**
- * Get date time
- *
- * @example getDateTime() // 2022-09-12T12:42:57+08:00
- */
-export function getDateTime() {
-  return dayjs().tz(getTimeZone()).format()
-}
+class Date {
+  private static instance: Date
 
-/**
- * Get time zone
- *
- * @example getTimeZone() // Asia/Shanghai
- */
-export function getTimeZone() {
-  let { timeZone } = Intl.DateTimeFormat().resolvedOptions()
-
-  if (TIME_ZONE) {
-    // Verify if the time zone is valid
-    try {
-      Intl.DateTimeFormat(undefined, { timeZone: TIME_ZONE })
-      timeZone = TIME_ZONE
-    } catch (e) {
-      LOG.warning(
-        `The time zone "${TIME_ZONE}" is not valid. Falling back to "${timeZone}"`
-      )
-    }
+  private constructor() {
+    // Singleton
   }
 
-  return timeZone
+  public static getInstance() {
+    if (Date.instance == null) {
+      Date.instance = new Date()
+    }
+
+    return Date.instance
+  }
+
+  /**
+   * Get date time
+   * @example getDateTime() // 2022-09-12T12:42:57+08:00
+   */
+  public getDateTime() {
+    return dayjs().tz(this.getTimeZone()).format()
+  }
+
+  /**
+   * Get time zone
+   * @example getTimeZone() // Asia/Shanghai
+   */
+  public getTimeZone() {
+    let { timeZone } = Intl.DateTimeFormat().resolvedOptions()
+
+    if (TIME_ZONE) {
+      // Verify if the time zone is valid
+      try {
+        Intl.DateTimeFormat(undefined, { timeZone: TIME_ZONE })
+        timeZone = TIME_ZONE
+      } catch (e) {
+        LOG.warning(
+          `The time zone "${TIME_ZONE}" is not valid. Falling back to "${timeZone}"`
+        )
+      }
+    }
+
+    return timeZone as string
+  }
 }
+
+export const DATE = Date.getInstance()
diff --git a/server/src/helpers/log.ts b/server/src/helpers/log.ts
index da8ceab9..562baf16 100644
--- a/server/src/helpers/log.ts
+++ b/server/src/helpers/log.ts
@@ -2,7 +2,7 @@ import fs from 'node:fs'
 import path from 'node:path'
 
 import { IS_TESTING_ENV } from '@/constants'
-import { getDateTime } from '@/helpers/date'
+import { DATE } from '@/helpers/date'
 
 class Log {
   static readonly ERRORS_PATH = path.join(
@@ -63,7 +63,7 @@ class Log {
    * TODO
    */
   public error(value: string) {
-    const data = `${getDateTime()} - ${value}`
+    const data = `${DATE.getDateTime()} - ${value}`
 
     if (!IS_TESTING_ENV) {
       if (fs.existsSync(Log.ERRORS_PATH)) {
diff --git a/test/unit/server/helpers/date.spec.js b/test/unit/server/helpers/date.spec.js
index ad5a57bd..e3e633b0 100644
--- a/test/unit/server/helpers/date.spec.js
+++ b/test/unit/server/helpers/date.spec.js
@@ -1,17 +1,19 @@
 import moment from 'moment-timezone'
 
-import { getDateTime, getTimeZone } from '@/helpers/date'
+import { DATE } from '@/helpers/date'
 
 describe('date helper', () => {
   describe('dateTime()', () => {
     test('returns date time with UTC', () => {
-      expect(getDateTime()).toBe(moment().tz(global.date.time_zone).format())
+      expect(DATE.getDateTime()).toBe(
+        moment().tz(global.date.time_zone).format()
+      )
     })
   })
 
   describe('timeZone()', () => {
     test('returns time zone', () => {
-      expect(getTimeZone()).toBe(global.date.time_zone)
+      expect(DATE.getTimeZone()).toBe(global.date.time_zone)
     })
   })
 })