Merge pull request #14 from smithki/development

Release v0.11.2

README.md

@@ -41,12 +41,30 @@ myLocalStorage.bar.spam = 'This works too!';
 const copied = { ...myLocalStorage };
 ```
 
-In TypeScript, you can pass an interface as a [generic type parameter](https://www.typescriptlang.org/docs/handbook/generics.html) to the factory function:
+Additionally, you can pass default values. This is handy if your stored data contains deep objects that need to be accessible even when the contained data is `undefined`:
+
+```ts
+const myLocalStorage = StorageProxy.createLocalStorage('my-namespace', {
+  one: {
+    two: 'three',
+    four: {},
+  },
+});
+
+console.log(myLocalStorage.one.two.three)        // => "three"
+myLocalStorage.one.two.three.four.five = 'six';  // Works!
+```
+
+In TypeScript, you can define the shape of your stored data by passing a [generic type parameter](https://www.typescriptlang.org/docs/handbook/generics.html) to the factory function:
 
 ```ts
 const myStorage = StorageProxy.createLocalStorage<{
   hello: string;
   foo: number[];
   bar: { baz: string, spam?: string };
 }>('my-namespace');
+
+myStorage.foo      // Works!
+myStorage.bar.baz  // Works!
+myStorage.yolo     // Compiler error!
 ```

package.json

@@ -1,6 +1,6 @@
 {
   "name": "storage-proxy",
-  "version": "0.11.1",
+  "version": "0.11.2",
   "description": "Use web storage (localStorage/sessionStorage) just like plain objects using ES6 Proxies.",
   "author": "Ian K Smith <[email protected]>",
   "license": "MIT",

src/lib.ts

@@ -24,6 +24,17 @@ export type StorageProxy<TStorageDefinitions> = Partial<TStorageDefinitions> & {
 
 // --- Utilities ------------------------------------------------------------ //
 
+/**
+ * Checks if the passed value is undefined.
+ *
+ * @param value - The value to check.
+ *
+ * @return Returns true if value is undefined, else false.
+ */
+export function isUndefined(value: any): value is undefined {
+  return value === undefined;
+}
+
 /**
  * Initializes the web storage interface. If no storage exists, we save an empty
  * object.
@@ -73,21 +84,21 @@ function createProxy<TStorageDefinitions extends any>(
     [isStorageProxy]: true,
     [storageTargetSymbol]: storageTarget,
   };
-  const proxyData = onChange(data, (path, value, prevValue) => {
+  const proxyData = onChange(data, (_path, value, prevValue) => {
     if (value === prevValue) return;
     window[storageTarget].setItem(namespace, JSON.stringify(proxyData));
   });
 
   const storageProxy = new Proxy(proxyData, {
-    get: (target, prop, receiver) => {
+    get: (_target, prop, _receiver) => {
       if (typeof proxyData[prop as any] === 'undefined') return null;
       return proxyData[prop as any];
     },
   });
 
   if (defaults) {
     for (const [key, value] of Object.entries(defaults)) {
-      if (!data[key]) {
+      if (isUndefined(data[key])) {
         storageProxy[key] = value;
       }
     }
@@ -106,7 +117,8 @@ export const StorageProxy = {
   /**
    * Creates a `localStorage` proxy object that can be used like a plain JS object.
    *
-   * @param namespace - An optional namespace to prefix `localStorage` keys with.
+   * @param namespace - A namespace to prefix `localStorage` keys with.
+   * @param defaults - Optional default values for this `StorageProxy` object.
    *
    * @return a `StorageProxy` object targeting `localStorage`.
    */
@@ -120,7 +132,8 @@ export const StorageProxy = {
   /**
    * Creates a `sessionStorage` proxy object that can be used like a plain JS object.
    *
-   * @param namespace - An optional namespace to prefix `sessionStorage` keys with.
+   * @param namespace - A namespace to prefix `sessionStorage` keys with.
+   * @param defaults - Optional default values for this `StorageProxy` object.
    *
    * @return a `StorageProxy` object targeting `sessionStorage`.
    */