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.
Tweaked by tabbott to not remove it from lister.py, linter_lib, and
friends, since those are intended to support both Python 2 and 3
(we're planning to extract them from the repository).
This causes `upgrade-zulip-from-git`, as well as a no-option run of
`tools/build-release-tarball`, to produce a Zulip install running
Python 3, rather than Python 2. In particular this means that the
virtualenv we create, in which all application code runs, is Python 3.
One shebang line, on `zulip-ec2-configure-interfaces`, explicitly
keeps Python 2, and at least one external ops script, `wal-e`, also
still runs on Python 2. See discussion on the respective previous
commits that made those explicit. There may also be some other
third-party scripts we use, outside of this source tree and running
outside our virtualenv, that still run on Python 2.
In this commit we modify our CSS parser not only to render the text from
a given CSS tokens produced but also enforce 4 space indentation on it.
Also we enforce some basic rules we would like our CSS to follow such as
* Always have "\n" in between the starting of body({) and body itself
and ending of the body and the closing of body(}).
* Use 4 space indents while having but something within the block
structure ( { .... } ).
* Have single space after ',' in between multiple selectors.
* Have only a single space in between selector and the starting of
block structure ({ ... }) if block structure starts on same line as
of selector.
eg. body {
body content here
}
Notice single space between 'body' and '{'.
Fixes: #1659.
This helps make the Zulip development environment somewhat more robust
to new contributors, since it will give them a nice warning if they
try running any of our development tools outside the Zulip virtualenv.
Fixes#3468.
This is a fairly major overhaul of the CSS parser to support
line numbers in error messages.
Basically, instead of passing "slices" of tokens around, we pass
indexes into the token arrays to all of our sub-parsers, which
allows them to have access to previous tokens in certain cases.
This is particularly important for errors where stuff is missing
(vs. being wrong).
In testing this out I found a few more places to catch errors.
`tools/lint-all` now calls the new `tools/check-css`
The css_parser library parsers CSS into a data structure
that remembers line numbers and columns of semantically
meaningful tokens and adjoining white space/tokens. It
is intended to be used for various linting tasks.
The file `tools/check-css` runs a few files through the
parser and makes sure they round trip. This has some value
right away, as files that fail to parse will cause an
exception to be thrown and thus alert developers to syntax
errors. We expect to grow this into more advanced linting
tasks eventually.