refactor: improved shuffle function (now using Durstenfeld shuffle)

tools/crypto/bip39-generator.vue

@@ -43,13 +43,13 @@ path: '/bip39-generator'
 
 <script lang="ts">
 import * as bip39 from 'bip39'
-import {shuffle} from '@/utils/string'
 import {Component, Ref} from 'nuxt-property-decorator'
 import {CopyableMixin} from '@/mixins/copyable.mixin'
 import Tool from '@/components/Tool.vue'
 import type {VForm} from '~/types/VForm'
+import {shuffleString} from '~/utils/random'
 
-const getRandomBuffer = () => Buffer.from(shuffle('0123456789abcdef'.repeat(16)).substring(0, 32), 'hex')
+const getRandomBuffer = () => Buffer.from(shuffleString('0123456789abcdef'.repeat(16)).substring(0, 32), 'hex')
 
 @Component({
   mixins: [CopyableMixin]

tools/crypto/token-generator.vue

@@ -38,7 +38,7 @@ path: '/token-generator'
 import {Component, Watch} from 'nuxt-property-decorator'
 import Tool from '~/components/Tool.vue'
 import {CopyableMixin} from '~/mixins/copyable.mixin'
-import {shuffle} from '~/utils/string'
+import {shuffleString} from '~/utils/random'
 
 const lowercase = 'abcdefghijklmopqrstuvwxyz'
 const uppercase = 'ABCDEFGHIJKLMOPQRSTUVWXYZ'
@@ -78,7 +78,7 @@ export default class TokenGenerator extends Tool {
       result += specials
     }
 
-    this.token = shuffle(result.repeat(this.config.length)).substring(0, this.config.length)
+    this.token = shuffleString(result.repeat(this.config.length)).substring(0, this.config.length)
   }
 }
 </script>

utils/random.ts

@@ -6,8 +6,25 @@ const randFromArray = (array: any[]) => array[Math.floor(random() * array.length
 
 const randIntFromInterval = (min: number, max: number) => Math.floor(random() * (max - min) + min)
 
+// Durstenfeld shuffle
+const shuffleArrayMutate = <T extends unknown>(array: T[]): T[] => {
+  for (let i = array.length - 1; i > 0; i--) {
+    const j = Math.floor(Math.random() * (i + 1));
+    [array[i], array[j]] = [array[j], array[i]];
+  }
+
+  return array
+}
+
+const shuffleArray = <T extends unknown>(array: T[]): T[] => shuffleArrayMutate([...array])
+
+const shuffleString = (str: string, delimiter: string = ''): string => shuffleArrayMutate(str.split(delimiter)).join(delimiter)
+
 export {
   randFromArray,
   randIntFromInterval,
-  random
+  random,
+  shuffleArray,
+  shuffleArrayMutate,
+  shuffleString
 }

utils/string.ts

@@ -1,5 +1,3 @@
 const capitalise = (s: string) => s.charAt(0).toUpperCase() + s.slice(1)
 
-const shuffle = (s: string) => s.split('').sort(() => 0.5 - Math.random()).join('')
+export {capitalise}
-
-export {capitalise, shuffle}