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Updated to 3.0

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Zakary Timson 2021-01-28 13:15:46 -05:00
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commit 954049d992
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56
README.md
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@ -1,30 +1,36 @@
# WebStorage
# WebStorage Decorators
A Javascript library that adds property decorators to sync a class property with the local or session storage.
A Javascript library that adds property decorators to sync a class property with the local & session storage. It also includes crypto-js so that sensitive information being stored on the client is not stored in plain text.
## Quick Setup
1. Install with: `npm install --save webstorage-decorators`
2. Add the decorator to your property and use as normal!
```typescript
import {LocalStorage, SessionStorage} from 'webstorage-decorators';
### Quick Setup
1. Install with: `npm install --save webstorage-decorators crypto-js`
2. Add the decorator to your property and you are done!
```javascript
import {LocalStorage, SessionStorage} from 'webstorage-decorators';
export class MyCustomClass {
@LocalStorage({key: 'site_theme', default: 'light_theme'}) theme: string;
@SessionStorage({encryptWith: config.entryptionKey}) thisUser: User;
export class SomeComponent {
@LocalStorage({
fieldName: 'customName',
encryptionKey: settings.encryptionToken,
defaultValue: 123
})
someProperty;
@SessionStorage(/* Accepts same optional paramters as the LocalStorage*/) user;
constructor(user) {
// This property will get its vallue from the local storage or default to 123 if the property doesn't exist
console.log(this.someProperty)
// Because of our SessionStorage decorator the user is automatically stored in the session storage
this.user = user
}
constructor() {
console.log(this.theme, localStorage.getItem('theme')); // Output: 'light_theme', 'light_theme'
console.log(this.user, localStorage.getItem('user')); // Output: null, undefined
user = {first: 'John', last: 'Smith', ...}
console.log(this.user, this.user == localStorage.getItem('user')); // Output: {first: 'John', last: 'Smith', ...}, true
}
}
```
## Caveats
Impure functions don't use the Object's setter preventing the storage from being updated. To prevent this use a pure
function or save it manually by reading the variable. (Reading triggers change detection & save if there are differences)
```typescript
@LocalStorage([1, 2]) example: number[];
example.push(3) // Impure & won't update storage
console.log(localStorage.getItem('example')) // Output: [1, 2];
example; // Trigger save
console.log(localStorage.getItem('example')) // Output: [1, 2, 3];
// OR
example = example.concat([3]); // Pure function requires you to use the setter triggering automatic saving
```

2
lib/src/webstorage.d.ts vendored
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@ -5,6 +5,8 @@
export interface WebStorageOptions {
/** Default value to provide if storage is empty */
default?: any;
/** Key to prevent plain text storage **/
encryptWith?: string;
/** Key to save under */
key?: string;
}

7
lib/src/webstorage.js
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@ -1,6 +1,7 @@
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.SessionStorage = exports.LocalStorage = void 0;
const crypto = require("crypto-js");
/**
* Automatically syncs localStorage with the decorated property.
*
@ -57,14 +58,18 @@ function storage(storage, opts) {
opts.key = key;
Object.defineProperty(target, key, {
get: function () {
const storageVal = storage.getItem(opts.key);
let storageVal = storage.getItem(opts.key);
if (storageVal == null || storageVal == 'null' || storageVal == 'undefined')
return opts.default || null;
if (opts.encryptWith != null)
storageVal = crypto.AES.decrypt(JSON.parse(storageVal), opts.encryptWith).toString(crypto.enc.Utf8);
return JSON.parse(storageVal);
},
set: function (value) {
if (value == null)
storage.removeItem(opts.key);
if (opts.encryptWith != null)
value = crypto.AES.encrypt(JSON.stringify(value), opts.encryptWith).toString();
storage.setItem(opts.key, JSON.stringify(value));
}
});

2
package.json
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@ -1,6 +1,6 @@
{
"name": "webstorage-decorators",
"version": "2.0.0",
"version": "3.0.0",
"description": "Decorators to sync class properties to Local/Session storage",
"main": "./lib/index.js",
"typings": "./lib/index.d.ts",

44
src/webstorage.ts
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@ -1,12 +1,15 @@
import * as crypto from 'crypto-js';
/**
* Options to be used with WebStorage decorators
* @category WebStorage
*/
export interface WebStorageOptions {
/** Default value to provide if storage is empty */
default?: any
default?: any;
/** Key to prevent plain text storage **/
encryptWith?: string;
/** Key to save under */
key?: string
key?: string;
}
/**
@ -20,13 +23,12 @@ export interface WebStorageOptions {
* }
* ```
*
* @category WebStorage
* @param defaultValue Default value to return if property does no exist inside localStorage.
* @param opts Any additional options
*/
export function LocalStorage(defaultValue?: any, opts: WebStorageOptions = {}) {
opts.default = defaultValue;
return storage(localStorage, opts);
return decoratorBuilder(localStorage, opts);
}
/**
@ -40,13 +42,27 @@ export function LocalStorage(defaultValue?: any, opts: WebStorageOptions = {}) {
* }
* ```
*
* @category WebStorage
* @param defaultValue Default value to return if property does no exist inside sessionStorage.
* @param opts Any additional options
*/
export function SessionStorage(defaultValue?, opts: WebStorageOptions = {}) {
opts.default = defaultValue;
return storage(sessionStorage, opts);
return decoratorBuilder(sessionStorage, opts);
}
/**
* **Internal use only**
*
* Fetch variable from storage & take care of any defaults, object definitions, encryption & serialization
*
* @param storage Web Storage API
* @param opts Any additional options
*/
function fromStorage(storage: Storage, opts: WebStorageOptions) {
let storedVal = storage.getItem(<string>opts.key);
if(storedVal == null) return opts.default != null ? opts.default : null;
if(opts.encryptWith != null) storedVal = JSON.parse(crypto.AES.decrypt(JSON.parse(storedVal), opts.encryptWith).toString(crypto.enc.Utf8));
return typeof storedVal == 'object' && !Array.isArray(storedVal) ? Object.assign(opts.default, storedVal) : storedVal;
}
/**
@ -54,22 +70,22 @@ export function SessionStorage(defaultValue?, opts: WebStorageOptions = {}) {
*
* Overrides the properties getter/setter methods to read/write from the provided storage endpoint.
*
* @hidden
* @category WebStorage
* @param storage Web Storage API
* @param opts Any additional options
*/
function storage(storage: Storage, opts: WebStorageOptions) {
function decoratorBuilder(storage: Storage, opts: WebStorageOptions) {
return function(target: object, key: string) {
if(!opts.key) opts.key = key;
let field = fromStorage(storage, opts);
Object.defineProperty(target, key, {
get: function() {
const storageVal = storage.getItem(<string>opts.key);
if(storageVal == null || storageVal == 'null' || storageVal == 'undefined') return opts.default || null;
return JSON.parse(storageVal);
if(field != fromStorage(storage, opts)) target[key] = field;
return field;
},
set: function(value) {
set: function(value?) {
field = value;
if(value == null) storage.removeItem(<string>opts.key);
if(opts.encryptWith != null) value = <any>crypto.AES.encrypt(JSON.stringify(value), opts.encryptWith).toString();
storage.setItem(<string>opts.key, JSON.stringify(value));
}
});

62
tests/webstorage.spec.ts
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@ -1,22 +1,32 @@
import {LocalStorage, SessionStorage} from "../src";
const CUSTOM_KEY = '__MY_KEY'
const CUSTOM_KEY = '_MY_KEY'
const ENCRYPTION_KEY = 'abc123';
class TestClass {
class TestType {
constructor(public first: string, public last: string) { }
fullName() { return `${this.last}, ${this.first}`; }
}
class TestStorage {
@LocalStorage() localStorage: any;
@LocalStorage({a: true, b: 'test', c: 3.14}) defaultedLocalStorage: any;
@LocalStorage(null, {key: CUSTOM_KEY}) customLocalStorage: any;
@LocalStorage(null, {encryptWith: ENCRYPTION_KEY}) encryptedLocalStorage: any;
@LocalStorage(new TestType('John', 'Smith')) objectLocalStorage!: TestType;
@SessionStorage() sessionStorage: any;
@SessionStorage({a: true, b: 'test', c: 3.14}) defaultedSessionStorage: any;
@SessionStorage(null, {key: CUSTOM_KEY}) customSessionStorage: any;
@SessionStorage(null, {encryptWith: ENCRYPTION_KEY}) encryptedSessionStorage: any;
@SessionStorage(new TestType('John', 'Smith')) objectSessionStorage!: TestType;
}
describe('WebStorage', () => {
let testComponent: TestClass;
describe('Webstorage Decorators', () => {
let testComponent: TestStorage;
beforeEach(() => {
localStorage.clear();
testComponent = new TestClass();
testComponent = new TestStorage();
});
describe('LocalStorage', () => {
@ -52,6 +62,26 @@ describe('WebStorage', () => {
expect(localStorage.getItem(CUSTOM_KEY)).toBe(JSON.stringify(testValue));
expect(testComponent.customLocalStorage).toBe(testValue);
});
test('Encrypted', () => {
const testValue = Math.random();
testComponent.encryptedLocalStorage = testValue;
expect(localStorage.getItem('encryptedLocalStorage')).not.toBe(JSON.stringify(testValue));
expect(testComponent.encryptedLocalStorage).toBe(testValue);
});
test('Impure Functions', () => {
testComponent.localStorage = [1];
testComponent.localStorage.push(2);
expect(localStorage.getItem('localStorage')).toStrictEqual(JSON.stringify([1]));
testComponent.localStorage; // Trigger save
expect(localStorage.getItem('localStorage')).toStrictEqual(JSON.stringify([1, 2]));
expect(testComponent.localStorage).toStrictEqual([1, 2]);
});
test('Object Functions', () => {
expect(testComponent.objectLocalStorage.fullName()).toEqual('Smith, John');
testComponent.objectLocalStorage.last = 'Snow';
testComponent.objectLocalStorage; // Trigger save
expect(testComponent.objectLocalStorage.fullName()).toEqual('Snow, John');
});
});
describe('SessionStorage', () => {
@ -87,5 +117,25 @@ describe('WebStorage', () => {
expect(sessionStorage.getItem(CUSTOM_KEY)).toBe(JSON.stringify(testValue));
expect(testComponent.customSessionStorage).toBe(testValue);
});
test('Encrypted', () => {
const testValue = Math.random();
testComponent.encryptedSessionStorage = testValue;
expect(sessionStorage.getItem('encryptedSessionStorage')).not.toBe(JSON.stringify(testValue));
expect(testComponent.encryptedSessionStorage).toBe(testValue);
});
test('Impure Functions', () => {
testComponent.sessionStorage = [1];
testComponent.sessionStorage.push(2);
expect(sessionStorage.getItem('sessionStorage')).toStrictEqual(JSON.stringify([1]));
testComponent.sessionStorage; // Trigger save
expect(sessionStorage.getItem('sessionStorage')).toStrictEqual(JSON.stringify([1, 2]));
expect(testComponent.sessionStorage).toStrictEqual([1, 2]);
});
test('Object Functions', () => {
expect(testComponent.objectSessionStorage.fullName()).toEqual('Smith, John');
testComponent.objectSessionStorage.last = 'Snow';
testComponent.objectSessionStorage; // Trigger save
expect(testComponent.objectSessionStorage.fullName()).toEqual('Snow, John');
});
});
});