Catching errors in environment variable type coercion


#1

https://gist.github.com/dmaze/308034415354fb0ec2e537157b3a39b8 is a minimal dry-system script that reads an integer value from an environment variable (using the :settings feature). If I run the script like

AN_INT=10 ruby ./dry-rb-env.rb

it will print out the number like I expect. But if I either

AN_INT=foo ruby ./dry-rb-env.rb
unset AN_INT; ruby ./dry-rb-env.rb

I get rather long backtraces that don’t mention the variable name at all.

Three questions:

(1) Is there a good way to trap these errors and give a succinct error message (something like AN_INT: invalid value for Integer(): "foo" would be great)?

(2) When I do report that, can I distinguish “missing” from “invalid”? (AN_INT is required, not AN_INT: can't convert nil into Integer)

(3) The value type has a .default(17) value, so shouldn’t that get picked up?


#2

@dmaze These feel like legitimate bugs to me, would appreciate it if you could file issues on dry-system’s GitHub repo! PRs are welcome too :wink: