Update Webpack / Babel config

* Added module path in package.json
* Marked as having no side-effects
* Disable commonjs on build

packages/core/babel.config.publish.js

@@ -7,7 +7,11 @@ module.exports = {
   ],
   plugins: [
     '@babel/transform-block-scoping',
-    '@babel/transform-modules-commonjs',
+    // NOTE(brent): Intentionally leave ES6 imports alone, they supported and
+    // recommended by Webpack
+    // (https://webpack.js.org/api/module-methods/#es6-recommended) and of
+    // course metro
+    // '@babel/transform-modules-commonjs',
     '@babel/proposal-class-properties',
     '@babel/proposal-object-rest-spread',
   ],

packages/core/package.json

@@ -4,6 +4,8 @@
   "description": "Core utilities for the react-navigation framework",
   "main": "dist/index.js",
   "react-native": "dist/index.js",
+  "module": "dist/index.js",
+  "sideEffects": false,
   "files": [
     "dist/",
     "src/",

packages/core/src/routers/KeyGenerator.ts

@@ -2,7 +2,7 @@ let uniqueBaseId: string = `id-${Date.now()}`;
 let uuidCount: number = 0;
 
 export function _TESTING_ONLY_normalize_keys(): void {
-  uniqueBaseId = 'id';
+  uniqueBaseId = `id`;
   uuidCount = 0;
 }
 

packages/core/src/utils/docsUrl.ts

@@ -1,3 +1,3 @@
-export default function docsUrl(path) {
+export default function docsUrl(path: string) {
   return `https://reactnavigation.org/docs/${path}`;
 }