Show dialog if application fails to start up properly

app/global_errors.js

@@ -1,16 +1,43 @@
-const addUnhandledErrorHandler = require('electron-unhandled');
+const electron = require('electron');
 
 const Errors = require('../js/modules/types/errors');
 
-//      addHandler :: Unit -> Unit
+const { app, dialog, clipboard } = electron;
+
+// We're using hard-coded strings in this file because it needs to be ready
+//   to report errors before we do anything in the app. Also, we expect users to directly
+//   paste this text into search engines to find the bugs on GitHub.
+
+function handleError(prefix, error) {
+  console.error(`${prefix}:`, Errors.toLogFormat(error));
+
+  if (app.isReady()) {
+    // title field is not shown on macOS, so we don't use it
+    const buttonIndex = dialog.showMessageBox({
+      buttons: ['OK', 'Copy error'],
+      defaultId: 0,
+      detail: error.stack,
+      message: prefix,
+      noLink: true,
+      type: 'error',
+    });
+
+    if (buttonIndex === 1) {
+      clipboard.writeText(`${prefix}\n${error.stack}`);
+    }
+  } else {
+    dialog.showErrorBox(prefix, error.stack);
+  }
+
+  app.quit();
+}
+
 exports.addHandler = () => {
-  addUnhandledErrorHandler({
-    logger: error => {
-      console.error(
-        'Uncaught error or unhandled promise rejection:',
-        Errors.toLogFormat(error)
-      );
-    },
-    showDialog: false,
+  process.on('uncaughtException', error => {
+    handleError('Unhandled Error', error);
+  });
+
+  process.on('unhandledRejection', error => {
+    handleError('Unhandled Promise Rejection', error);
   });
 };