Change normalisation of ordered-imports

[aboyton]

This makes it consistent with TypeScript's Organize Imports command

Fixes #4063

PR checklist

• Addresses an existing issue: #0000
• New feature, bugfix, or enhancement
  • Includes tests
• Documentation update

Overview of change:

This makes the sorting consistent with what TypeScript's Organise Imports ordering does, see microsoft/TypeScript#25114

Is there anything you'd like reviewers to focus on?

Nothing in particular.

CHANGELOG.md entry:

[bugfix] Make ordered-imports consistent with TypeScript's Organise Imports ordering
[new-rule-option] case-insensitive-legacy for ordered-imports rule

[palantirtech]

Thanks for your interest in palantir/tslint, @aboyton! Before we can accept your pull request, you need to sign our contributor license agreement - just visit https://cla.palantir.com/ and follow the instructions. Once you sign, I'll automatically update this pull request.

[johnwiseheart]

Your code itself looks like a pretty simple change, but I have some questions:

Consider the following:

import { foo, _bar } from 'baz';

Before this PR, fixing this code would result in:

import { _bar, foo } from 'baz';

right? Because we were previously enforcing that underscored variables would be at the beginning, I think that makes this a breaking change. Can you confirm @giladgray or @suchanlee?

One fix for this might be to allow either way as an option to the rule, in which case in a future major release we can swap the default from being at the front to at the back.

[aboyton]

Yes, technically this is a breaking change. It is enforcing a different ordering. You could provide an option to allow people to migrate, or you could tell people to run --fix to get the new ordering. Up to you.

[johnwiseheart]

I think that the option is probably the best idea. Are you interested in implementing that? Unfortunately the maintainers don't have a lot of time to develop features other than trying to manage the PRs and issues.

[aboyton]

I've added a option to restore the legacy behaviour as requested. This diff would be much smaller if #4214 is merged first.

[elsmr]

Hi all, is there anything blocking this PR from being merged? Seems like it has been idle since Nov 2018. This fix would enable us to use this lint rule since a lot of devs use "Organize Imports" from TypeScript 😄

[aboyton]

If it needs rebasing I'm happy to do that.

[JoshuaKGoldberg]

Since this is a breaking change, it's blocked on when the next TSLint version (either minor or major - unclear to me) is ready to be released. Unknown yet when that is, sorry!

[elsmr]

Ok! thanks for the reply

[JoshuaKGoldberg]

@adidahiya another one with the clean-lockfile CI freeze :o

[adidahiya]

thanks for the PR @aboyton!