Implement Ctrl-^ to switch to the most recently visible tab.

[bronson]

Implement Ctrl-^ to switch to the most recently visible tab.

Vim's docs claim: Edit the alternate file. Mostly the alternate file is the previously edited file. However, experimentation shows that editing doesn't seem to matter. The alternate file actually appears to be the previously viewed file.

Writing the feature was easy, but writing the tests has beaten me. @maxbrunsfeld, would appreciate a little guidance when you get a chance.

When mergeable, this should address #719

[bronson]

FWIW, my terrible attempts at writing tests (first by mocking views, second by actually trying to instantiate TextEditors) are here: https://github.com/bronson/vim-mode/commits/tab-motion-bad-tests

Clearly I need help. :)

[jacekkopecky]

I'm lightly reviewing vim-mode PRs and this one strikes me as having too little to do with vim-mode.

[jraines]

Apologies in advance for this being little more than a 👍 -- but I'm in the camp that considers CTRL-^ (move to alternate buffer) essential in my vim usage. Since I don't know much about the goals of this plugin or the best practices for Atom package modularity, I'm wondering if someone could point out:

1. Why it has too little to do with vim-mode?
2. If it is, in fact, relevant to this repo -- how can I help contribute to getting this merged?
3. If it should be a different plugin, in which case I'll do some research on contributing that.

[bronson]

1. because it's about window/tab navigation, not editing. You gotta draw the line somewhere. Editing is reasonably discrete and easy to test and, even then, vim-mode is a beast.

2 & 3) you could turn this PR into a plugin. The switching works great (in Atom 1.0 anyway, in theory it should still be fine). I got discouraged when I couldn't figure out how to test it.

Feel free to ask questions.

[bronson]

oops, didn't realize this PR was still open. closing!