Webpack: Promise is not a constructor

[cah-ricksuggs]

Great library, I am really getting into the pouchdb ecosystem!

I received a error message stating that "Promise is not a constructor." After investigating the issue, I noticed that pouch-quick-search depends on an outdated version of pouchdb-promise, which created a version conflict in my webpack bundle.

Someone proposed just modifying pouch-utils to require('pouchdb-promise').default but that would break when running in nodejs.

I was able to workaround the issue by augmenting the webpack configuration of my angular app, by adding a resolve alias to always pull in the newer version of pouchdb-promise, and using the index.js rather than index.es.js

const path = require('path');
const webpackDefault = require('@ionic/app-scripts/config/webpack.config');
const webpackMerge = require('webpack-merge');

const customConfig = {
  dev: {
    resolve: {
      alias: {
        'pouchdb-promise$': "pouchdb-promise/lib/index.js"
      }
    }
  },
  prod: {
    resolve: {
      alias: {
        'pouchdb-promise$': "pouchdb-promise/lib/index.js"
      }
    }
  }
};

module.exports = webpackMerge(webpackDefault, customConfig);

Is there an easy way to update this library to distribute a ES6 module version for webpack to use, and a ES5 (CommonJS?) version for nodejs to use? I noticed other pouchdb libraries are using the "main" and "module" package.json properties to achieve this. I'd be happy to open a pull request after getting some direction.

[silverbackdan]

Thanks so much for posting the results f your investigation on this. I'm sure I'm not the only one you've saved loads of debugging time for.

Here's a slightly sorter config without the webpack-merge dependency if using Ionic. I've left in another alias too @environment which is part of a solution to set environment variables.

const path = require('path');
const webpackConfig = require('@ionic/app-scripts/config/webpack.config.js');

module.exports = function () {
  webpackConfig[process.env.IONIC_ENV].resolve.alias = {
    "@environment": path.resolve(__dirname + '/../../src/config/config.' + process.env.IONIC_ENV + '.ts'),
    'pouchdb-promise$': "pouchdb-promise/lib/index.js"
  };
  return webpackConfig;
};

[david-dev0415]

Thanks so much for posting the results f your investigation on this. I'm sure I'm not the only one you've saved loads of debugging time for.

Here's a slightly sorter config without the webpack-merge dependency if using Ionic. I've left in another alias too @environment which is part of a solution to set environment variables.

const path = require('path');
const webpackConfig = require('@ionic/app-scripts/config/webpack.config.js');

module.exports = function () {
  webpackConfig[process.env.IONIC_ENV].resolve.alias = {
    "@environment": path.resolve(__dirname + '/../../src/config/config.' + process.env.IONIC_ENV + '.ts'),
    'pouchdb-promise$': "pouchdb-promise/lib/index.js"
  };
  return webpackConfig;
};

Hi, I have problems. I am new to this and I have the same error, where I paste this code that they have put. Help me please

[daveywc]

@davidspalaciof You need to add a file somewhere in your project that contains the code above. Then reference that file in your package.json as follows:

"config": { "ionic_webpack": "./config/webpack.config.js" },

In the example above I have a folder named "config" at the root of my project that contains a file named webpack.config.js.

[daveywc]

@silverbackdan Your solution works very nicely - thank you. @cah-ricksuggs thanks to you for the original solution.

[isumix]

Hi, I get the same issue using pouchdb-replication-stream.
But I could't find how to resolve alias in create-react-app without ejecting.
So I've just imported plugin from dist like:
var replicationStream = require('pouchdb-replication-stream/dist/pouchdb.replication-stream.min.js');
Hope this helps someone.
Is there any better way of doing it?

[sureshvv]

Hi, I get the same issue using pouchdb-replication-stream.
But I could't find how to resolve alias in create-react-app without ejecting.
So I've just imported plugin from dist like:
var replicationStream = require('pouchdb-replication-stream/dist/pouchdb.replication-stream.min.js');
Hope this helps someone.
Is there any better way of doing it?

Is there an explanation for why this works?