Add electron environment check, fix #376

Author: jeromewu

package-lock.json

@@ -60,6 +60,7 @@
     "bmp-js": "^0.1.0",
     "file-type": "^12.4.1",
     "idb-keyval": "^3.2.0",
+    "is-electron": "^2.2.0",
     "is-url": "1.2.2",
     "node-fetch": "^2.6.0",
     "opencollective-postinstall": "^2.0.2",

package.json

@@ -1,7 +1,11 @@
+const isElectron = require('is-electron');
+
 module.exports = (key) => {
   const env = {};
 
-  if (typeof window === 'object') {
+  if (isElectron()) {
+    env.type = 'electron';
+  } else if (typeof window === 'object') {
     env.type = 'browser';
   } else if (typeof importScripts === 'function') {
     env.type = 'webworker';