Things About Reagent I'd Like To Improve

If I set a style to nil .... I got a completely incomprehensible error at run-time

If I include [] as markup I get an error, but no information about where it occurs

Things About CLJS I'd Like To Improve

I've figured out one puzzling thing about clojurescript (when using "auto" compiles).

Every now and again, my program stops working completely, I get an exception and I'm puzzled. (exception is something like "undefined doesn't have a call method") Eventually, I "clean" and recompile, and bingo the compiler puts out an error. I think to myself "Why didn't it do that in the first place".

Now, as far as I can tell its all to do with the incremental compiler and the way it only compiles one file at a time, and ONLY files that have changed (not the ones that depend on it).

Imagine that I have namespace X, uses namespace Y (aka X.cljs and Y.cljs)

X depends on Y. In effect, within X.cljs there is a reference to Y/some-func

And then you go to Y.cljs and change the name of the function from "some-func" to "my-func"

At this point the code in X is wrong. It still refers to Y/some-func.

But the auto compile process won't pick that problem up. Because it only recompiled Y when we changed it. The auto compile doesn't know "X depends on Y, therefore I should also compile X when Y changes." To catch the problem in X, you'd have to recompile X but only Y is recompiled..

But when you do a "clean", it recompiles X and bingo you get to see the error.

lein

If you make a change to project.cljs, you'll have to restart lein cljsbuild auto <name> So a common trap is to add a dependency to project.cljs but still get errors.

Baffling Compile time

Leaving out the [] on a defn results in a compile-time error that is baffling and unhelpful.

Linux

By default you'll probably have an old version of lein.

Run lein --version and make sure it is at least 2.3.N