hexpm VS changelog.com

I was thinking of porting this library to Elixir. But first, I searched on hex.pm and Surprising. I found two packages that support merging tailwind classes: twix and tails

I often reference https://github.com/hexpm/hexpm which is the code behind hex.pm.

Feel free to take a look at the package manager and let me know if there are any libraries that you need that are missing. https://hex.pm/

I can assure you I'm not spending my time inventing new libraries. In the past 3 or so years of working in Elixir there have been maybe 2 or 3 cases where I was looking for a library and couldn't find a suitable one. Writing my own code to cover those cases took a few hours. This should hardly be a deal breaker for anyone if you take into account dozens, maybe even hundreds of hours the ecosystem could save you in the long run if your project is a good fit for it.

Before getting started you need to have both Elixir, the Hex package manager, the PostgreSQL relational database server and Node.js installed on your local computer to be able to follow through this guide.

We can then look at that function and see that ultimately it calls Supervisor.start_link(...) on a bunch of children. That means that one process's only job is to start up all those child processes and "supervise" them, meaning if any of them crash it will be notified and be able to handle that. I note that one of the processes runs the code in the module Hexpm.RepoBase which means it's in charge of managing database connections, and one runs the code in the module HexpmWeb.Endpoint which is the process in charge of managing the Phoenix side of things, handling incoming requests, spinning up new processes to handle each one, and directing them to the right controllers and stuff. Then there's a bunch of other modules listed, for things like rate limiting, billing reports, and other stuff. You can look in the codebase for those listed modules if you're interested, but the thing to note is that by putting the module name there, what happens is the supervisor will spawn a new process and run the start_link function of that module within that new process.

I was looking for a solution to run tests automatically every time I save any changes. The best way so far for me is the following hex package:

API server and website for Hex https://github.com/hexpm/hexpm

Dependency Current Latest Status bunt 0.2.0 0.2.0 Up-to-date cowlib 2.11.0 2.11.0 Up-to-date credo 1.6.1 1.6.3 Update possible db_connection 2.4.1 2.4.1 Up-to-date decimal 2.0.0 2.0.0 Up-to-date earmark_parser 1.4.19 1.4.20 Update possible postgrex 0.15.13 0.16.2 Update not possible To view the diffs in each available update, visit: https://hex.pm/l/AsY7q

Now it’s time to decide on a name for your package. In this guide I will be creating a new Ueberauth package. If you were to go on http://hex.pm and look at other Ueberauth packages, you notice there is a certain pattern followed. This will make the decision easy for us on what to call our Uberauth package that will implement the Patreon OAuth flow.

Go to the website https://hex.pm and search for the faker library to grab the latest version, so you can copy that to your mix config file, at the time of the making of this tutorial the latest version is 0.17.0, add the following to your project dependencies inside your mix.exs file:

Another https://dagger.io fan here. Have been using it since late 2021 to continuously deploy a Phoenix app to Fly.io: https://github.com/thechangelog/changelog.com/pull/395. Every commit goes into production.

This is what the GHA workflow currently looks like: https://github.com/thechangelog/changelog.com/blob/c7b8a57b2...

FWIW, you can see how everything fits together in this architecture diagram: https://github.com/thechangelog/changelog.com/blob/master/IN...

I really like the work that you're doing Thomas, this is the right approach. FWIW, https://fly.io/blog/carving-the-scheduler-out-of-our-orchest... is one of my favourite posts on your blog.

For everyone else reading this, we have been running https://changelog.com on Fly.io since April 2022. This is what our architecture currently looks like: https://github.com/thechangelog/changelog.com/blob/master/IN...

After 15 months & more than 100 million requests served by our Phoenix + PostgreSQL app running on Fly.io, I would be hard pressed to find a reason to complain.

Changelog.com

I see this criticism a lot but I don't think it has anything to do with macros specifically and more so to do with lack of familiarity with Elixir. I've felt the same way about Django being magic because I had trouble following the class hierarchy. It makes a lot more sense now because I'm more familiar with Python and Django. But even today I'll be looking deeper at something and ask WTF it's doing. In that respect, Elixir codebases are easier to me. The module depth seems "shallower" and I don't have to disambiguate between what behavior is caused by class inheritance or an imported function.

When I first tried to use Elixir several years ago Ecto.Schema [0] seemed complex and magical, but then I came to realize it's just converting module attributes to runtime code. There is not really that much complex macro logic going on.

>This also leads to cryptic errors where you get an error in non existant lines of code.

When was the last time you used Elixir? This isn't a problem I can recall having in the last 4 years or so of using Elixir.

>following the control flow in Phoenix is like a maze because of all the macro substitutions.

Can you clarify what you mean by this? A specific case as to where this happened for you would help. Phoenix's use of macros is actually pretty light [1] except for some very low level stuff. You can even see how frequently a developer will use macros in Phoenix by searching `__using__` in the codebase [2]. It's not used as much as people think. The majority is for views and controllers and only to provide a very thin layer of support on top of your regular use of code. As an example, the "macro magic" in Phoenix.Controller is just handling some basics for giving a layout and view to Plug and handling fallback actions for exceptions. You could do the plug calls manually and I think it would be safe to not use any macros in your controller code.

Another familiarity issue with the language (and any language really) is understanding what is meaningful in a stack trace and what isn't. And the likely cause of the error in the first place. Is it syntax? Is it mistyping a variable? Is a function just used improperly? (wtf is init_p_do_apply and why does it show up in every stacktrace?) You're juggling all these different issues - learning a new paradigm, a new syntax, not knowing how to extend things. It's obviously going to be a little overwhelming and, if not strictly required, we might just pick a different language that we're more familiar with.

[0]: https://github.com/elixir-ecto/ecto/blob/master/lib/ecto/sch...

[1]: https://github.com/thechangelog/changelog.com/blob/master/li... (not mine, I just go here to show the most frequent use of macros in Phoenix)

[2]: https://github.com/phoenixframework/phoenix/search?q=__using...

changelog.com used to be WordPress, then became a Phoenix app because it needed features that were hacky to implement & then manage in WP. It's more of a podcasting platform these days rather than a CMS.

The code in this repo tells the truth about what it is, and even shows how it works: https://github.com/thechangelog/changelog.com