It shouldn't be required to use if/unless on the same line as do_something if code coverage tools are being used

[abotalov]

Styleguide has a rule:

Favor modifier if/unless usage when you have a single-line body.

do_something if some_condition

But it seems that Ruby's Coverage module (and thus other coverage tools like Simplecov based on it) support only line coverage and thus I won't see if do_something was invoked during test suite.

So I propose to change rule to:

Favor modifier if/unless usage when you have a single-line body if you don't use code coverage tools.

# ok (if you use code coverage tools)
if some_condition
  do_something
end

[bbatsov]

Interesting point - I had never thought about this. However, it seems to me that we shouldn't sacrifice code clarity to compensate for tool deficiencies.

[abotalov]

@bbatsov Actually Coverage module is part of MRI. So it's not the tool - it's Ruby itself.

It seems to me that until Ruby implementations will provide a way to check if part of line of code has been executed Ruby style guide should take current situation into account.

[arr-dev]

I was just thinking about creating this ticket, but search saved me. I also think that this is something that should be recommended since coverage has no way of checking this.

[jdickey]

Agreed (with @abotalov and @soul-rebel). Coverage (and Simplecov, etc) are line-coverage tools passing themselves off as statement coverage, or C0. Nobody seems to have a C1-level (branch coverage) tool for Ruby, per Stack Overflow and further explained over at Code Climate. IMO, the team that delivers reliable C1 and C2 (execution-path) coverage for Ruby will be heroes well above the level of the (excellent) rails-core team.

Declaring that we "shouldn't sacrifice code clarity to compensate for tool deficiencies" is a comforting ideal, but in the real world, it's not going to fly very far. Yes, if you're doing BDD/TDD "right", you should never have less than 100% (C0-ish) coverage. The mere existence of CodeClimate as a viable business shows that many teams don't meet that ideal. It's a virtual certainty that multiple Gems on which we all depend, don't meet that ideal. Given that, a useful tool. practice or standard acts to compensate for the weaknesses of other commonly-used tools when it is not overly disruptive to do so.

Just my 0.84 cents (ruddy inflation!)

[lee-dohm]

I'd support the modification as long as it specifically states "code coverage tools that only support line coverage" with perhaps a link like what @jdickey mentions. I agree with @bbatsov that in general we shouldn't sacrifice code clarity because of tools, we should just fix the tools ... but I also feel that giving an exception in very specific circumstances isn't bad either.

[bbatsov]

I'm pretty sure the majority of Ruby users would simply discard the suggested change. Ruby has always placed strong emphasis on readability and make a compromise with readability for the sake of tooling is unlikely to resonate with them. Personally, I'll never drop the modifier form. I use simplecov as well, but don't really care whether the code metric is accurate or not. One can get excellent coverage with a pretty crappy test suite; I care about the quality of tests.

[bbatsov]

I'm closing this ticket due to no recent activity. Feel free to re-open it if you ever come back to it.