feat(generatePassword): Add generatePassword function with tests (#175)

Author: RobAnthony01

src/generate-password.js

@@ -0,0 +1,58 @@
+export default generatePassword
+
+/**
+ * Original source: https://stackoverflow.com/questions/12635652/generate-a-secure-password-in-javascript
+ * This function would generate a password
+ * it is a modified copy
+ * @param {int}len - The minimum length of the returned password
+ * @param {int}capitals - The number of characters which must be capitalised
+ * @param {int}lowercases - The number of characters which must be lowercase
+ * @param {int}specials - the number of characters which must be special characters
+ * @param {int}digits - The number of characters which must be digits
+ * @return {string} - The randomised password
+**/
+function generatePassword(len = 8, capitals = 1, lowercases = 1, specials = 1, digits = 1) {
+  let password = ''
+  const specialChars = '!@#$%^&*()_+{}:"<>?\\|[];\',./`~'
+  const lowercaseChars = 'abcdefghijklmnopqrstuvwxyz'
+  const uppercaseChars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
+  const digitChars = '0123456789'
+
+  const allChars = specialChars + lowercaseChars + uppercaseChars + digitChars
+
+  password += pick(specialChars, specials)
+  password += pick(lowercaseChars, lowercases)
+  password += pick(uppercaseChars, capitals)
+  password += pick(digitChars, digits)
+  password += pick(allChars, Math.max(len - capitals - lowercases - specials - digits, 0))
+  password = shuffle(password)
+
+  return password
+}
+
+function pick(characterList, count) {
+  let chars = ''
+  for (let i = 0; i < count; i++) {
+    chars += characterList.charAt(Math.floor(Math.random() * characterList.length))
+  }
+
+  return chars
+}
+
+// Credit to @Christoph: http://stackoverflow.com/a/962890/464744
+function shuffle(str) {
+  const array = str.split('')
+  let tmp, current
+  let top = array.length
+
+  if (top) {
+    while (--top) {
+      current = Math.floor(Math.random() * (top + 1))
+      tmp = array[current]
+      array[current] = array[top]
+      array[top] = tmp
+    }
+  }
+
+  return array.join('')
+}

src/index.js

@@ -62,6 +62,7 @@ import removeAccents from './remove-accents'
 import getQueryStringValue from './get-query-string-value'
 import isLeapYear from './leap-year'
 import removeElementFromArray from './removeElementFromArray'
+import generatePassword from './generate-password'
 
 export {
   reverseArrayInPlace,
@@ -128,4 +129,5 @@ export {
   lessThan,
   isLeapYear,
   removeElementFromArray,
+  generatePassword,
 }

test/generate-password.test.js

@@ -0,0 +1,54 @@
+import test from 'ava'
+import {generatePassword} from '../src'
+
+test('returns a string', t => {
+  const expected = 'string'
+  const actual = typeof generatePassword(10)
+  t.deepEqual(actual, expected)
+})
+
+test('returns an empty string', t => {
+  const expected = ''
+  const actual = generatePassword(0, 0, 0, 0, 0)
+  t.deepEqual(actual, expected)
+})
+
+test('Returns a password of the correct length', t => {
+  const expected = 10
+  const actual = generatePassword(10).length
+  t.deepEqual(actual, expected)
+})
+
+test('Returns a password of the default length', t => {
+  const expected = 8
+  const actual = generatePassword().length
+  t.deepEqual(actual, expected)
+})
+
+test('Returns a password with CAPITALS', t => {
+  const expected = 'X'
+  const regex = /[A-Z]{10}/
+  const actual = generatePassword(10, 10, 0, 0, 0).replace(regex, 'X')
+  t.deepEqual(actual, expected)
+})
+
+test('Returns a password with lowercase', t => {
+  const expected = 'X'
+  const regex = /[a-z]{10}/
+  const actual = generatePassword(10, 0, 10, 0, 0).replace(regex, 'X')
+  t.deepEqual(actual, expected)
+})
+
+test('Returns a password with digits', t => {
+  const expected = 'X'
+  const regex = /[0-9]{10}/
+  const actual = generatePassword(10, 0, 0, 0, 10).replace(regex, 'X')
+  t.deepEqual(actual, expected)
+})
+
+test('Returns a password with specialchars', t => {
+  const expected = 'X'
+  const regex = /[!@#$%^&*()_+{}:"<>?\\|\[\];',./`~]{10}/
+  const actual = generatePassword(10, 0, 0, 10, 0).replace(regex, 'X')
+  t.deepEqual(actual, expected)
+})