Problems with Style/TernaryParentheses autocorrection

[benhutton]

When updating to the latest rubocop version, we ran rubocop -a and ended up with two bad lines:

-        (defined? thing) ? thing : 'Message'
+        defined? thing ? thing : 'Message'

-        state: (states.include? status) ? status : 'pending',
+        state: states.include? status ? status : 'pending',

And perhaps there are other, better, ways to write these lines.

Obviously, a "real" problem is that the parens are in the wrong place. It should be defined?(thing) instead of (defined? thing). It should be states.include?(status) instead of (states.include? status).

But it would be preferable to not attempt a bad autocorrect and just flag it as an error and let me sort it out myself.

---

Expected behavior

Should not attempt to autocorrect

Actual behavior

Attempts to autocorrect to invalid code

Steps to reproduce the problem

Have code which matches the above "-" lines, and then run rubocop -a

RuboCop version

Include the output of rubocop -V:

$ rubocop -V
0.42.0 (using Parser 2.3.1.2, running on ruby 2.3.1 x86_64-linux)

[Drenmi]

@benhutton: You are correct. We should never auto-correct in a way that breaks code, or changes its meaning.

I implemented this cop originally. I will see if I can fix this when I have time (which may or may not be anytime soon.) If someone else feels like giving it a go, please feel free to do so. 😀