undefined is not an object (evaluating 'db.crypto(password).then')

Using PouchDb and CryptoPouch in an Ionic 2 app fails when trying to encrypt a database. I have created this project to demonstrate the issue.

The basic usage is this:

import * as PouchDB from 'pouchdb';
import * as CryptoPouch from 'crypto-pouch';

export class TutorialPage {
  constructor(public navCtrl: NavController, public menu: MenuController, translate: TranslateService) {

    PouchDB.plugin(CryptoPouch);
    var db = new PouchDB('kittens');
    var password = "password";

    db.crypto(password);

    // db.crypto(password).then(function () {
    //   return db.put({_id: 'foo', bar: 'baz'});
    // }).then(function () {
    //     return db.get('foo');
    // }).then(function (doc) {
    //     console.log('decrypted', doc);
    //     return db.removeCrypto();
    // }).then(function () {
    //     return db.get('foo');
    // }).then(function (doc) {
    //     console.log('encrypted', doc);
    // })

This code will run, but just doing db.crypto(password) apparently will do nothing. According to this StackOverflow answer, This is needed:

db.crypto(password).then(function () {
   // <-- encryption set up
})

However, trying this, for example by uncommenting the above commented out code will cause this runtime error:

EXCEPTION: Error in ./MyApp class MyApp - inline template:16:2 caused by: undefined is not an object (evaluating 'db.crypto(password).then')

Not sure why the first db.crypto(password) will work but the db.crypto(password).then will not.

This may be a setup issue similar to this issue where the answer was to standalone/crypto-pouch, but I'm not sure how that relates to an Ionic 2 project.

calvinmetcalf / crypto-pouch

undefined is not an object (evaluating 'db.crypto(password).then') #52