Need a Ruby helper for finding undefined variables and methods

[CharlesWinstead]

Hi All,

I'm definitely a newbie. I've tried to read the faq first but the
links weren't working. I did read through some old posts.

I understand that the dynamic nature of Ruby is pretty powerful, but I
have an application where our Ruby code is managing the execution of
design tools that take a long time to run. We're getting bit by having
typos in our methods or variables that we don't find until execution
time, which can take hours. Is there any utility or settings in Ruby
that can flag these at compile time?

Thanks!

-Charles

 

[Jano Svitok]

Hi All,

I'm definitely a newbie. I've tried to read the faq first but the
links weren't working. I did read through some old posts.

I understand that the dynamic nature of Ruby is pretty powerful, but I
have an application where our Ruby code is managing the execution of
design tools that take a long time to run. We're getting bit by having
typos in our methods or variables that we don't find until execution
time, which can take hours. Is there any utility or settings in Ruby
that can flag these at compile time?

I used unit tests and rcov for that - write simple tests that run at least
once through the code to catch these typos. Then run them with rcov
(gem install rcov) to see the coverage - what code has been tested and
what not. Finally either write more tests for the uncovered parts or look
at them more carefully ;-)

The thoroughness of this depends on the tests you write - it's possible that
in one scenario you get object that has one particular method, and another
time you get different object that hasn't. Your goal is to cover as
much of these
cases as possible.

You don't have to call your long-running stuff (=design tools?) in the tests -
you should avoid them as much as possible, using so called mock objects to
simulate the behavior of the expensive methods/objects. The goal is to
have tests,
that will quickly check your code for errors. For more info see
test/unit, zentest
or general test-driven development (TDD) docs.

Other than that, there's no compile time, there's "parse time" interleaved with
"execution time".

Try turning -w on (i.e. ruby -w <your script>) to see more warnings.

Maybe something from ParseTree gem and friends might be useful as well, but
I don't think there's a tool to do this particular thing (check for
undefined methods).