This is a good, well-thought out critique. While much of it rings true, I can't say I completely agree:
Wrt. static type checking, JET.jl does the job for me. I agree it still feels too immature with slowness and important edge cases it fails to consider. More importantly, the ecosystem itself needs to fully embrace type stability for it to be optimally useful, since otherwise you will get a shitton of false positives from functioning, yet unstable dependencies. The good news is that all of these things are improving quickly for JET.jl - it's getting faster and more robust. It still feeds immature since it's actively being developed.
There is also the linter, which is available in VSCode. It's pretty good. Nowhere near the level of rust-analyzer, but still decent.
You can easily have error types in Julia - see the package ErrorTypes.jl. It's not standard to use it, but I use it in my work code, and it works quite well.
You can absolutely write tests next to code and just run one test - see InlineTests.jl and ReTest.jl
HOWEVER:
* The latency is still terrible, and it really, _really_ hinders development. I don't see that being significantly solved in the next many years, only marginally improved. This can reasonably be a showstopper for some people. You learn tribal knowledge to lessen its blow (wrap things in modules, use Revise etc), but there is no sugarcoating it: It blows.
* The lack of statically enforceable interfaces is a real problem, and I think this will NEVER be solved in Julia. There just doesn't seem to be any real motivation from the core team, and no agreement in the community on what such a solution even should look like.
* The lack of separation of tests is very annoying as well. That might literally be impossible in Julia since part of its promise is that you can dynamically change definitions that affect other modules. It's what contributes to its great composability. But it also means you need to test ALL of Base if you change one thing.
Wrt. static type checking, JET.jl does the job for me. I agree it still feels too immature with slowness and important edge cases it fails to consider. More importantly, the ecosystem itself needs to fully embrace type stability for it to be optimally useful, since otherwise you will get a shitton of false positives from functioning, yet unstable dependencies. The good news is that all of these things are improving quickly for JET.jl - it's getting faster and more robust. It still feeds immature since it's actively being developed.
There is also the linter, which is available in VSCode. It's pretty good. Nowhere near the level of rust-analyzer, but still decent.
You can easily have error types in Julia - see the package ErrorTypes.jl. It's not standard to use it, but I use it in my work code, and it works quite well.
You can absolutely write tests next to code and just run one test - see InlineTests.jl and ReTest.jl
HOWEVER:
* The latency is still terrible, and it really, _really_ hinders development. I don't see that being significantly solved in the next many years, only marginally improved. This can reasonably be a showstopper for some people. You learn tribal knowledge to lessen its blow (wrap things in modules, use Revise etc), but there is no sugarcoating it: It blows.
* The lack of statically enforceable interfaces is a real problem, and I think this will NEVER be solved in Julia. There just doesn't seem to be any real motivation from the core team, and no agreement in the community on what such a solution even should look like.
* The lack of separation of tests is very annoying as well. That might literally be impossible in Julia since part of its promise is that you can dynamically change definitions that affect other modules. It's what contributes to its great composability. But it also means you need to test ALL of Base if you change one thing.