Rubocop: New Cop Idea: Explicit operator precedence

[tejasbubane]

Is your feature request related to a problem? Please describe.

This is a request for new cop based on @bbatsov's comment here.

Describe the solution you'd like

The cop should check for explicit parens when operators with varying precedence are used in a statement.

# bad
a && b || c
10 + 20 * 3

# good
(a && b) || c
10 + (20 * 3)

Describe alternatives you've considered

NA

Additional context

We need to decide if the cop should consider all operators or only commonly used ones.

[bbatsov]

Well, I have to say I love the idea! 😉

[rahul404]

Hi @bbatsov, I have made a PR for this feature. There is one issue I can fix in it.
The test case to fix a ** b * c / d % e + f - g << h >> i & j | k ^ l fails. Somehow the cop exercises the correction method only once.

[mvz]

It would be nice to have this depend somehow on the complexity of the expression. But then again, I think a ** b * c / d % e + f - g << h >> i & j | k ^ l would be equally hard to comprehend with parentheses.