The CSS linter was pretty hard to reason about. It was
pretty flexible about certain things, but then it would
prevent seemingly innocuous code from getting checked in.
This commit overhauls the pretty-printer to be more composable,
where every object in the AST knows how to render itself. It
also cleans up a little bit of the pre_fluff/post_fluff logic
in the parser itself, so comments are more likely to be "attached"
to the AST node that make sense.
The linter is actually a bit more finicky about newlines, but
this is mostly a good thing, as most of the variations before
this commit were pretty arbitrary.
This restyles and rewords some of the emoji style section to look
better and fit it more with the current style guide.
Tweaked by tabbott to modify the historical migration rather than
adding a new one. This is OK because the emojiset choices text change
doesn't touch the database; it's just a Django Python code thing.
Also removed translation tags, since we don't need them for a set of
brand names.
The intended use of $$ is for inline expressions, not for multiline
ones; ```math is an acceptable alternative for the latter. Hence,
the $$-syntax for inline TeX no longer permits newlines within it.
This was also necessary for the next change to be sensible; namely
allowing for spaces around both $$ when crafting inline TeX instead of
forcing everything to be crammed together, e.g. $$x=7$$. In order to
avoid uninentionally creating inline expressions, the opening and
closing $$'s of an inline expression must now both exactly consist of
two dollar signs, no more and no less.
Fixes: #6488.
Some of the calls in our codebase will call for the `.keys()` method a
lot, so this caches the results and returns them rather than mapping
the array if it knows the state to be the same as before.
If a user clicks on the pill container and not directly on a pill
or on an "x" inside of a pill, it should be presumed they are
trying to input new text. This effectively makes the whole non-pill
section an input bar.