Add support for tabs in indentation.

[DracoAter]

As a stubborn tab user, I would like to have the ability to check, if all my code is indented with tabs, and also automatically correct indentation from spaces to tabs. So I:

Add support for indentation with tabs. Supports auto-correction.
The existing Layout/Tab is renamed into Layout/IndentationStyle.

Layout/IndentationStyle now can be configured:

# SupportedStyles: spaces, tabs
Layout/IndentationStyle:
  EnforcedStyle: spaces # default

EnforcedStyle: spaces will look for tabs in indentation and correct them into spaces.
EnforcedStyle: tabs will look for spaces in indentation and correct them into tabs.

Previous functionality of Layout/Tab that looked for tabs in places other than indentation is removed.
Hopefully this issue will be covered by TrailingWhitespace cop.

[bbatsov]

The proposed change is fine by me. Just a couple of notes:

• I think "tabs" and "spaces" make for better style names
• We'll probably have to rename this cop, as its current name is a bit confusing after the addition of the configuration

[DracoAter]

I have fixed the linting issues and changed SupportedStyles to plural (spaces, tabs).

Concerning the renaming, of the cop, that would be a major version update then. Probably it is possible to get away with minor version update, if we split it into 2 different cops. Existing Layout/Tab will search and fix the tabs outside of indentation, and a new cop (e.g. Layout/IndentationStyle will look for and fix tabs/spaces only in indentation.

If you need, I can implement any strategy you suggest.

[bbatsov]

Concerning the renaming, of the cop, that would be a major version update then.

We still haven't released 1.0, so that's not a big deal. I doubt the rename would impact many people, anyways, as it's not common to disable this cop.

Existing Layout/Tab will search and fix the tabs outside of indentation, and a new cop (e.g. Layout/IndentationStyle will look for and fix tabs/spaces only in indentation.

I do like this approach, though, as it's a bit weird that now the cop cares about both indentation and trailing tabs. I don't recall if it detects tabs in other contexts. I'm thinking that in essence the second cop can be something like "TrailingWhitespace" or something.

[bbatsov]

Actually, we do have a trailing whitespace cop already, so unless there are other contexts in which a tab shouldn't appear I guess this check can be folded in the existing cop.

[koic]

IMHO, I think the cop name can be left as Layout/Tab by using the option names below.

• Rename spaces to soft_tabs
• Rename tabs to hard_tabs

Of course it could be changed to a more suitable cop name or better approach.

[DracoAter]

Currently it checks for tabs anywhere. Does not matter where the tab is (except inside a string), it is replaced with number of indentation_width spaces, even in the middle of the line.

[DracoAter]

So what is your final decision, what do I need to do now: rename, split or nothing?

[bbatsov]

Let's go with the new name IndentationStyle or UnitsOfIndentation and drop the check for tabs that are not used for indentation purposes. If someone can come up with a better name - that'd be fine by me.

I don't see much point in a cop checking for tabs at random place in the file. Hopefully the TrailingWhitespace cop already addresses trailing tabs.

[bbatsov]

Don't forget to mention this breaking change in the changelog and add the cop to the list of renamed/removed cops.

[bbatsov]

You'll have to changed this to 0.82.

[bbatsov]

This file is auto-generated on release from the changelog. You shouldn't update it manually.

[bbatsov]

Please add a **(Breaking)** prefix here.

[bbatsov]

Thanks for working on this! I might not be fan of tabs, but I'm happy we'll be more accommodating to the people who are! :-)

[DracoAter]

Thank you for the collaboration and quick replies.

[DracoAter]

I screwed up url in changelog, could you fix it?

[@DracoAter]: https:/github.com/DracoAter

Add one more slash before github.

[bbatsov]

Sure.