component VS onramp

* Lifecycle management: Mount, Integrant or Component (https://github.com/tolitius/mount https://github.com/weavejester/integrant and https://github.com/stuartsierra/component)

When you start to have multiple stateful components (the database, the HTTP server, your Redis connection, a page cache, etc.), then you'll want to use a library like component that manages their (inter-)dependencies and provides a consistent notion of lifecycle.

Today I released a new version of Reveal Pro — dev.vlaaad/reveal-pro {:mvn/version "1.3.308"} — that adds sticker integration for system libraries such as mount, component and integrant!

I agree with the main sentiment from the article. Although I do think they are discussing Inversion of control more-so than dependency injection.

One of my first languages was .net and I was never able to really understand DI in that context that well.

Actually using javascript and ducktyping made me understand what it actually was.

I remember a .net job interview where I had to write a micro-service and opted to construct the dependency graph in the main function initialising "all" the classes there. Instead of discussing the pro's and con's of that approach they berated me for not using a DI framework (No I did not land that job, but in hindsight it was the most expensive job interview I've ever had. The room was filled with 8 developers going over my code).

The main thing the article glosses over is state. something people with a functional background hide from. But if you look at something like the httpclient in .net. I think it took the .net world like 10 years to start using the httpclient properly. Scope and lifetime of those kind of objects are important. managing connection pools, retry state, throttling or the incoming http request. DI does make that kind of thing easieR (I'm not saying it makes it better)

Look at clojure's component(https://github.com/stuartsierra/component), I'm not a clojure expert by far. But it is kinda DI/IOC in a functional language.

In closing we can agree that it is underused in the right places and overused in the wrong ones.

https://github.com/stuartsierra/component#no-function-should-take-the-entire-system-as-an-argument

Yeah like I mentioned I'm not like super sold on the everything-should-be-an-actor paradigm, but I find value in DDD + a light implementation of Components (similar to stuartsierra/component).

https://github.com/stuartsierra/component for managing components lifecycles in projects

I prefer to try to solve a range of puzzles (I guess 4clojure is alright). When on-boarding folks who don't know clojure, I provide them with some repl-based tutorials and on-ramping exercises. on-ramp. They then attempt to work through the exercises (a combination of project euler stuff and some curated problems) and discuss their thinking about solutions and implementations along the way. Then we refactor where things can be made more idiomatic. This seems to have been successful for the last 4 iterations.

You might like to try the bridge and torch puzzle here among others since it's similar but has different constraints and adds a cost element to the path.