[EnigmaCurry]

I am learning Clojure this week, and my test project is a calculator / unit convertor [1]. I wanted it to run in the CLI and on the web, so it targets several hosted platforms: Babashka / JVM / ClojureScript. It's a single code base written in cross platform .cljc files. I already have about 250 tests written for the abstract calculator API, run as a test matrix across platforms, so the project is already in a good place for testing a new runtime.

I just learned about basilisp from the parent comment, so I asked Claude to add Python support to the same .cljc files I have, and we finished the port in about 30mins, and then fixed Python specific test cases for another 30 mins, but now all of the existing tests are passing. That's impressive in several ways.

Portability is achieved by testing. You have to put the platforms you want to support into your test harness, and the earlier the better. A calculator is purely functional, so this is a fairly straight forward port and really easy to test for. I'm not sure about larger projects, but it seems like there is something seriously right about Clojure's design that makes this easy to do.

[1] https://github.com/EnigmaCurry/calc