Recently, I came across a number of open source Ruby (or majority of it was Ruby) projects on GitHub that when checked with a code analyzing tool like Rubocop, create a lot of offenses.
Now, most of these offenses include using double quotation marks instead of single quotes (when not interpolation), not following the 2 spaces per level rule, exceeding the 80 character line length rule, or using { and } for multi-line blocks.
[The] Ruby style guide recommends best practices so that real-world
Ruby programmers can write code that can be maintained by other
real-world Ruby programmers. ~ Source: Ruby Style Guide
Although they are small and easy to fix, is it appropriate to change the coding style of an open source project by fixing the offenses and making a Pull Request? I acknowledge that some projects, like Rails, do not accept cosmetic changes and some are just too large to "fix" all at once (Rails for example generates over 80,000 offenses when Rubocop is run – regardless, they have their own small set of coding conventions to follow when contributing). After all, the Ruby Style Guide is there for a reason together with tools like Rubocop.
People appreciate consistency so making these kinds of changes is kind of doing a good thing for the Ruby community in general, right?
[The author(s) of the Ruby Style Guide] didn't come up with all the
rules out of nowhere – they are mostly based on my extensive career as
a professional software engineer, feedback and suggestions from
members of the Ruby community and various highly regarded Ruby
programming resources, such as "Programming Ruby 1.9" and "The Ruby
Programming Language". ~ Source: Ruby Style Guide
Isn't not following community coding style conventions and best practices basically encouraging bad practices?
Best Answer
Ask the maintainers.
Coding style is a quite subjective discussion, and rules like maximum line length of 80 characters are fairly subjective - while general agreement should be that shorter lines are better to read, 80 might be too restrictive for some with today's screen sizes and IDE's.
Other rules can be ignored on purpose, too. For instance, a developer might consider global use of double quotes better for him and be willing to accept the "risk" of accidental interpolation and an extremely small increase on parsing time.
Many maintainers also don't like large coding style changes as they are boring to review and there is a chance that it might introduce errors. For example, a string could be switched to single quote, even though it contained a deliberate interpolation and should have been using double quotes. Maintainers prefer to do style cleanups while working on that actual code so they can verify style changes don't introduce new bugs.