mothership | A music player interface | Music Player library

I don't have enough reputation to comment, so I'll put my thoughts here. First of all, XMLHttpRequest is old and outdated. The fetch API is much more reliable and easy. Anyways, back to your code. I think your problem is that you are checking the xhr.status before the response is ready. You're also sending the request before you define a callback. Try using this code instead:

It depends. If you're using a resources bundler (such as Webpack), you can require it directly and the path will be set for you:

You could do something like this:

Here is the code I have in place and currently working in my app:

It seems you aren't really understanding the change in design philosophy with a module architecture. You don't make things global. A module imports the other modules that it needs and gets its capabilities from the import, not from some global set of functions. In a modular architecture, there would be NO global script. That's why your thinking isn't quite fitting into the modular architecture.

exports is a means of making certain entry points or data publicly accessible to anyone who imports the module while keeping everything else local to the module. One must import the module to get access to these entry points.

So, is exports intended for communication between sub-modules and modules then, rather than for between modules and a global script? That is to say modules never export, only sub-modules do?

Mostly. But, even a top level module could have exports. They wouldn't be used for anything in the project in which it was a top level module, but it could perhaps be used in a different project where it wasn't a top level module and was imported by some other module. The module architecture gets you to think about code reuse and code sharing without having to do a lot of extra work. The normal way you write your project should automatically create a bunch of reusable code.

That might have been the final piece of the puzzle I needed. So exports is just for sub-modules (and sibling-modules), then? Standalone, self-contained top-level modules don't need exports because any functionality happens right there in the module - the data never needs to go anywhere else. (Is that right?)

Yes. Unless you might want to be able to reuse that module in another project where you did import it and did want to import some entry points or data.

I may wish to write some optional modules which declare functions, calculate variables and objects and, after calculation, make all the declared and calculated values available to global-scripts.js. But... how do I then import what these module scripts calculate into my global-script.js?

You will get rid of your global script entirely in a module design. You will have a top level module that imports other modules.

So, do I now need to have two global scripts?

Nope, you get rid of the global script and you don't make things global any more.

Or is there an alternative standard architecture which we're all supposed to be using?

The module architecture:

With the information given I cannot be sure, but your stack trace suggests the problem is an empty configuration parameter for your Postgres connection, specifically libpq. See the list of environmental parameters here. If your shell environment variables are set differently then the app's, that would explain why you can open a console on production without problems and instantiate and save records while the app cannot.

As a debugging step, have your app dump all its environment variables to a log file and make sure that any required database parameters are either set in the environment or in the production section of database.yml

You are not initializing the FirebaseApp. In onCreate(), write this first:

According to the supported instance types for EMR https://docs.aws.amazon.com/emr/latest/ManagementGuide/emr-supported-instance-types.html, there could be two factors affecting the instance type selection you are seeing.

One factor is the EMR release. The other factor is the region you are in. The documentation States some instant types may not be available in all regions. There's also a footnote regarding releases, specifying that certain you were generation instance types are only available for a given EMR release.

Also note, per John R. below:

us-east-2 (Ohio) and at least some other regions have the newer instance types. us-east-1 (N. Virginia) seems not to have them

Double-check those factors against your current environment to confirm instance type availability.

I suspect that your startup scripts are launching a different Python than the one you have installed discord to.

Try adding the line,