insomnia/packages/insomnia-app/app/plugins/context/app.js

// @flow
import type {Plugin} from '../';
import * as electron from 'electron';
import {showAlert} from '../../ui/components/modals/index';

export function init (plugin: Plugin): {app: Object} {
  return {
    app: {
      alert (message: string): Promise<void> {
        return showAlert({title: `Plugin ${plugin.name}`, message: message || ''});
      },
      getPath (name: string): string {
        switch (name.toLowerCase()) {
          case 'desktop':
            return electron.remote.app.getPath('desktop');
          default:
            throw new Error(`Unknown path name ${name}`);
        }
      },
      async showSaveDialog (options: {defaultPath?: string} = {}): Promise<string | null> {
        return new Promise(resolve => {
          const saveOptions = {
            title: 'Save File',
            buttonLabel: 'Save',
            defaultPath: options.defaultPath
          };

          electron.remote.dialog.showSaveDialog(saveOptions, filename => {
            resolve(filename || null);
          });
        });
      }
    }
  };
}