(feat): support SSR out-of-the-box by no-op'ing in Node

- add a `nodeNoop` option that is `true` by default
  - generally folks do not want to hydrate their store during SSR, so
    no-op by default and require explicit opt-in to Node hydration
  - see #6 for discussion

(docs): add `nodeNoop` option and section on Node and SSR usage to
give more details and note possible gotchas

README.md

@@ -58,9 +58,17 @@ persist('some', someStore, {
  - **jsonify** *bool* Enables serialization as JSON (default: `true`).
  - **whitelist** *Array\<string\>* Only these keys will be persisted (defaults to all keys).
  - **blacklist** *Array\<string\>* These keys will not be persisted (defaults to all keys).
+ - **nodeNoop** *bool* Whether this should no-op in a Node environment (default: `true`). See below for more details.
 
 - returns a void Promise
 
+### Node and SSR Usage
+
+To support Server-Side Rendering (SSR) out-of-the-box, `persist` will no-op in a Node environment by default.<br>
+Please note that it uses `typeof window === 'undefined'` to check. [`window` is defined in React Native](https://stackoverflow.com/questions/49911424/what-does-the-variable-window-represent-in-react-native), but may not be in test runners and other simulated environments.
+
+If you'd like to hydrate your store in Node (vs. in the browser, which is the standard usage), set `nodeNoop` to `false` and `storage` to a supported provider for Node.
+
 ## Examples
 
 None yet, but can take a look at [agilgur5/react-native-manga-reader-app](https://github.com/agilgur5/react-native-manga-reader-app) which uses it in production.

src/index.ts

@@ -9,14 +9,25 @@ export interface IOptions {
  storage?: any,
  jsonify?: boolean,
  readonly whitelist?: Array<string>,
- readonly blacklist?: Array<string>
+ readonly blacklist?: Array<string>,
+ nodeNoop?: boolean
 }
 type StrToAnyMap = {[key: string]: any}
 
 export const persist: IArgs = (name, store, options = {}) => {
- let {storage, jsonify, whitelist, blacklist} = options
+ let {storage, jsonify, whitelist, blacklist, nodeNoop} = options
 
- if (typeof window.localStorage !== 'undefined' && (!storage || storage === window.localStorage)) {
+ // no-op in node by default to support SSR out-of-the-box
+ // require explicit opt-in to hydrate server-side
+ if (!nodeNoop) { nodeNoop = true }
+ if (nodeNoop && typeof window === 'undefined') { return Promise.resolve() }
+
+ // use AsyncLocalStorage by default or if window.localStorage was passed in
+ if (
+ typeof window !== 'undefined' &&
+ typeof window.localStorage !== 'undefined' &&
+ (!storage || storage === window.localStorage)
+ ) {
  storage = AsyncLocalStorage
  }
  if (!storage) {