feat: add the resetDefaultDictionary method

This provides the end user with an easy ability to reset the dictionary in use back to the default.
It also refactors the constructor to have separate values for the default dictionary and the
dictionary in use.

Resolves: #29

API.md

@@ -7,12 +7,14 @@
     -   [dictionary][3]
         -   [Parameters][4]
         -   [Examples][5]
-    -   [encode][6]
-        -   [Parameters][7]
-        -   [Examples][8]
-    -   [decode][9]
-        -   [Parameters][10]
-        -   [Examples][11]
+    -   [resetDefaultDictionary][6]
+        -   [Examples][7]
+    -   [encode][8]
+        -   [Parameters][9]
+        -   [Examples][10]
+    -   [decode][11]
+        -   [Parameters][12]
+        -   [Examples][13]
 
 ## AlphanumericEncoder
 
@@ -32,7 +34,7 @@ Returns or sets the current dictionary.
 
 #### Parameters
 
--   `newDictionary` **[string][12]** (If setting) String of unique letters and numbers, in order, for the new dictionary
+-   `newDictionary` **[string][14]** (If setting) String of unique letters and numbers, in order, for the new dictionary
 
 #### Examples
 
@@ -47,19 +49,36 @@ console.log(encoder.dictionary) // 'ABCD'
 encoder.dictionary = 'ABCDA' // Throws error because the letter 'A' is repeated
 ```
 
--   Throws **[RangeError][13]** if setting dictionary to `null`, `undefined` or empty string (i.e. `''`)
--   Throws **[RangeError][13]** if `newDictionary` contains a non-alphanumeric character
--   Throws **[RangeError][13]** if `newDictionary` has a repeating character
+-   Throws **[RangeError][15]** if setting dictionary to `null`, `undefined` or empty string (i.e. `''`)
+-   Throws **[RangeError][15]** if `newDictionary` contains a non-alphanumeric character
+-   Throws **[RangeError][15]** if `newDictionary` has a repeating character
 
-Returns **[string][12]** (If used as getter) The current dictionary in use
+Returns **[string][14]** (If used as getter) The current dictionary in use
+
+### resetDefaultDictionary
+
+Reset the dictionary in use to the default.
+
+#### Examples
+
+```javascript
+const encoder = new AlphanumericEncoder()
+console.log(encoder.dictionary) // 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
+encoder.dictionary = 'ABCD'
+console.log(encoder.dictionary) // 'ABCD'
+encoder.resetDefaultDictionary()
+console.log(encoder.dictionary) // 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
+```
+
+Returns **void**
 
 ### encode
 
 Takes any number and converts it into a base (dictionary length) letter combo.
 
 #### Parameters
 
--   `integerToEncode` **[number][14]** Base 10 integer. If passed a non-integer number, decimal values are truncated.
+-   `integerToEncode` **[number][16]** Base 10 integer. If passed a non-integer number, decimal values are truncated.
     Passing zero, negative numbers, or non-numbers will return `undefined`.
 
 #### Examples
@@ -93,23 +112,22 @@ console.log(encoder.encode(733)) // 'CBBA'
 ```
 
 ```javascript
-const encoder = new AlphanumericEncoder()
 console.log(encoder.encode('A')) // undefined
 console.log(encoder.encode(null)) // undefined
 console.log(encoder.encode(undefined)) // undefined
 ```
 
--   Throws **[RangeError][13]** if `integerToEncode` exceeds the maximum safe integer for Javascript (`2^53 - 1 = 9007199254740991`).
+-   Throws **[RangeError][15]** if `integerToEncode` exceeds the maximum safe integer for Javascript (`2^53 - 1 = 9007199254740991`).
 
-Returns **[string][12]** Dictionary encoded value
+Returns **[string][14]** Dictionary encoded value
 
 ### decode
 
 Takes any string and converts it into a base 10 integer based on the defined dictionary.
 
 #### Parameters
 
--   `stringToDecode` **[string][12]** If passed a non-integer number, decimal values are truncated.
+-   `stringToDecode` **[string][14]** If passed a non-integer number, decimal values are truncated.
     Passing an empty string, `null`, or `undefined` will return `undefined`.
 
 #### Examples
@@ -137,21 +155,23 @@ console.log(encoder.decode('ADBAC')) // 551
 console.log(encoder.decode('ANE')) // undefined
 ```
 
--   Throws **[RangeError][13]** if the decoded integer exceeds the maximum safe integer for Javascript (`2^53 - 1 = 9007199254740991`).
+-   Throws **[RangeError][15]** if the decoded integer exceeds the maximum safe integer for Javascript (`2^53 - 1 = 9007199254740991`).
 
-Returns **[number][14]** Positive integer representation. If one of the characters is not present in the dictionary, it will return `undefined`.
+Returns **[number][16]** Positive integer representation. If one of the characters is not present in the dictionary, it will return `undefined`.
 
 [1]: #alphanumericencoder
 [2]: #examples
 [3]: #dictionary
 [4]: #parameters
 [5]: #examples-1
-[6]: #encode
-[7]: #parameters-1
-[8]: #examples-2
-[9]: #decode
-[10]: #parameters-2
-[11]: #examples-3
-[12]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
-[13]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/RangeError
-[14]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number
+[6]: #resetdefaultdictionary
+[7]: #examples-2
+[8]: #encode
+[9]: #parameters-1
+[10]: #examples-3
+[11]: #decode
+[12]: #parameters-2
+[13]: #examples-4
+[14]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
+[15]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/RangeError
+[16]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number

index.js

@@ -9,11 +9,12 @@
  */
 class AlphanumericEncoder {
     constructor() {
-        /**
-         * @private
-         * @type {string} Internal property holding the dictionary in use
-         */
-        this._dictionary = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' // Default dictionary is the English alphabet, all capitalized, in order
+        /** @private */
+        this._defaultDictionary = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' // Default dictionary is the English alphabet, all capitalized, in order
+        /** @private */
+        this._dictionaryInUse = ''
+        /** @private */
+        this.resetDefaultDictionary()
     }
 
     /**
@@ -63,11 +64,27 @@ class AlphanumericEncoder {
         }
 
         // Validation is complete. Update the internal property.
-        this._dictionary = uppercaseDictionary
+        this._dictionaryInUse = uppercaseDictionary
     }
 
     get dictionary() {
-        return this._dictionary
+        return this._dictionaryInUse
+    }
+
+    /**
+     * Reset the dictionary in use to the default.
+     * @default `ABCDEFGHIJKLMNOPQRSTUVWXYZ`
+     * @returns {void}
+     * @example
+     * const encoder = new AlphanumericEncoder()
+     * console.log(encoder.dictionary) // 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
+     * encoder.dictionary = 'ABCD'
+     * console.log(encoder.dictionary) // 'ABCD'
+     * encoder.resetDefaultDictionary()
+     * console.log(encoder.dictionary) // 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
+     */
+    resetDefaultDictionary() {
+        this._dictionaryInUse = this._defaultDictionary
     }
 
     /**
@@ -103,7 +120,6 @@ class AlphanumericEncoder {
      * console.log(encoder.encode(733)) // 'CBBA'
      *
      * @example
-     * const encoder = new AlphanumericEncoder()
      * console.log(encoder.encode('A')) // undefined
      * console.log(encoder.encode(null)) // undefined
      * console.log(encoder.encode(undefined)) // undefined