Setup mocha to use babel

.babelrc

@@ -0,0 +1,7 @@
+{
+  "presets": [["@babel/preset-env", {
+    "targets": {
+      "browsers": ["last 2 Chrome versions"]
+    }
+  }]]
+}

package.json

@@ -7,12 +7,13 @@
   "files": [
     "dist"
   ],
+  "sideEffects": false,
   "scripts": {
-    "test": "mocha",
+    "test": "mocha --require @babel/register",
     "prebuild": "npm run build:clean",
     "build:clean": "rimraf ./dist",
     "build": "rollup -c",
-    "coverage": "nyc --reporter=text mocha",
+    "coverage": "nyc --require @babel/register --reporter=text mocha",
     "coveralls": "nyc npm test && nyc report --reporter=text-lcov | coveralls",
     "lint": "eslint ./src",
     "prepublish": "npm run lint && npm run test && npm run build"
@@ -29,6 +30,7 @@
   "devDependencies": {
     "@babel/core": "^7.4.5",
     "@babel/preset-env": "^7.4.5",
+    "@babel/register": "^7.12.10",
     "chai": "^4.2.0",
     "chai-as-promised": "^7.1.1",
     "coveralls": "^3.0.3",
@@ -38,13 +40,13 @@
     "mocha": "^6.1.4",
     "mocha-lcov-reporter": "^1.3.0",
     "nyc": "^14.1.1",
+    "regenerator-runtime": "^0.13.7",
     "rimraf": "^2.6.3",
     "rollup": "^1.13.1",
     "rollup-plugin-babel": "^4.3.2",
     "sinon": "^7.3.2",
     "sinon-chai": "^3.3.0"
   },
-  "dependencies": {},
   "directories": {
     "test": "test"
   },

rollup.config.js

@@ -12,8 +12,6 @@ module.exports = {
   plugins: [
     babel({
       exclude: 'node_modules/**',
-      babelrc: false,
-      presets: ['@babel/env'],
     }),
   ],
 };