SSR Support (#115)

Add SSR support by adding "type": "module" and useIsomorphicLayoutEffect

By setting "type": "module", node treats the javascript files within the package as ES modules. Since some of the config files are CJS, we need to indicate that by updating the file extension from '.js' to '.cjs' or else node 16+ will throw an error

J=none
TEST=manual

Connect this to the [ SSR Support ](yext/search-ui-react#125) branch in the component library and smoke test with the Yext Sites starter

THIRD-PARTY-NOTICES

@@ -593,6 +593,36 @@ This package contains the following license and notice below:
 
 -----------
 
+The following NPM package may be included in this product:
+
+ - [email protected]
+
+This package contains the following license and notice below:
+
+MIT License
+
+Copyright (c) Mateusz Burzyński
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+-----------
+
 The following NPM package may be included in this product:
 
  - [email protected]

package.json

@@ -1,9 +1,10 @@
 {
   "name": "@yext/answers-headless-react",
-  "version": "1.1.0-beta.11",
+  "version": "1.1.0-beta.12",
   "types": "./lib/src/index.d.ts",
   "main": "./lib/src/index.js",
   "module": "./lib/src/index.js",
+  "type": "module",
   "files": [
     "lib",
     "src"
@@ -16,7 +17,8 @@
     "generate-notices": "generate-license-file --input package.json --output THIRD-PARTY-NOTICES --overwrite"
   },
   "dependencies": {
-    "@yext/answers-headless": "^1.1.0-beta.12"
+    "@yext/answers-headless": "^1.1.0-beta.12",
+    "use-isomorphic-layout-effect": "^1.1.2"
   },
   "devDependencies": {
     "@babel/preset-env": "^7.16.5",

src/useAnswersState.tsx

@@ -1,6 +1,7 @@
-import { useContext, useLayoutEffect, useRef, useState } from 'react';
+import { useContext, useRef, useState } from 'react';
 import { State } from '@yext/answers-headless';
 import { AnswersHeadlessContext } from './AnswersHeadlessContext';
+import useLayoutEffect from 'use-isomorphic-layout-effect';
 
 export type StateSelector<T> = (s: State) => T;
 

src/utils/acquireSessionId.ts

@@ -1,9 +1,13 @@
 import { v4 as uuidv4 } from 'uuid';
 /**
  * Retrieves session id from local storage, or generates a new uuid to use as session id.
- * The new id is then stored in local storage.
+ * The new id is then stored in local storage. Returns null if the sessionStorage API is
+ * unavailable. (e.g. The function is running on the server for SSR).
  */
 export default function acquireSessionId(): string | null {
+  if (typeof(window) === 'undefined') {
+    return null;
+  }
   try {
     let sessionId = window.sessionStorage.getItem('sessionId');
     if (!sessionId) {