This patch changes the preview style so that string splitters respect
Unicode East Asian Width[^1] property. If you are not familiar to CJK
languages it is not clear immediately. Let me elaborate with some
examples.
Traditionally, East Asian characters (including punctuation) have
taken up space twice than European letters and stops when they are
rendered in monospace typeset. Compare the following characters:
```
abcdefg.
글、字。
```
The characters at the first line are half-width, and the second line
are full-width. (Also note that the last character with a small
circle, the East Asian period, is also full-width.) Therefore, if we
want to prevent those full-width characters to exceed the maximum
columns per line, we need to count their *width* rather than the number
of characters. Again, the following characters:
```
글、字。
```
These are just 4 characters, but their total width is 8.
Suppose we want to maintain up to 4 columns per line with the following
text:
```
abcdefg.
글、字。
```
How should it be then? We want it to look like:
```
abcd
efg.
글、
字。
```
However, Black currently turns it into like this:
```
abcd
efg.
글、字。
```
It's because Black currently counts the number of characters in the line
instead of measuring their width. So, how could we measure the width?
How can we tell if a character is full- or half-width? What if half-width
characters and full-width ones are mixed in a line? That's why Unicode
defined an attribute named `East_Asian_Width`. Unicode grouped every
single character according to their width in fixed-width typeset.
This partially addresses #1197, but only for string splitters. The other
parts need to be fixed as well in future patches.
This was implemented by copying rich's own approach to handling wide
characters: generate a table using wcwidth, check it into source
control, and use in to drive helper functions in Black's logic. This
gets us the best of both worlds: accuracy and performance (and let's us
update as per our stability policy too!).
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Richard Si <sichard26@gmail.com>
Fixes#3506
We can't simply escape the quotes in a naked f-string when merging string groups, because backslashes are invalid.
The quotes in f-string expressions should be toggled (this is safe since quotes can't be reused).
This fix also means implicitly concatenated f-strings with different quotes can now be merged or quote-normalized by changing the quotes used in expressions. e.g.:
```diff
raise sa_exc.UnboundExecutionError(
"Could not locate a bind configured on "
- f'{", ".join(context)} or this Session.'
+ f"{', '.join(context)} or this Session."
)
```
The option is `max-line-length` with dashes, not underscores. The config option name is given in the output of `pycodestyle -h`, which can also be checked on https://pep8.readthedocs.io/en/stable/intro.html#example-usage-and-output:
```
Configuration:
The project options are read from the [pycodestyle] section of the
tox.ini file or the setup.cfg file located in any parent folder of the
path(s) being processed. Allowed options are: exclude, filename,
select, ignore, max-line-length, max-doc-length, hang-closing, count,
format, quiet, show-pep8, show-source, statistics, verbose
```
When trying to format a project from the outside, the verbose output
shows says that there are symbolic links that points outside of the
project, but displays the wrong project path, meaning that these
messages are false positives.
This bug is triggered when the command is executed from outside a
project on a folder inside it, causing an inconsistency between the
path to the detected project root and the relative path to the target
contents.
The fix is to normalize the target path using the project root before
processing the sources, which removes the presence of the incorrect
messages.
---
The test attemps to emulate the behavior of the CLI as closely as
posible by patching some `pathlib.Path` methods and passing certain
reference paths to the context object and `black.get_sources`.
Before the associated fix was introduced, this test failed because
some of the captured files reported the presence of a symlink due to
an incorrectly formated path. The test also asserts that only a single
file is reported as ignored, which is part of the expected behavior.
Signed-off-by: Antonio Ossa Guerra <aaossa@uc.cl>
Revert deleted documentation on setting up Black using IntelliJ
external tool or file watcher utilities. These are still worth keeping
because some peole might not want to use a third-party plugin or
install Blackd's extra dependencies.
Co-authored-by: Richard Si <sichard26@gmail.com>
Co-authored-by: Jordan Ephron <JEphron@users.noreply.github.com>
Co-authored-by: Richard Si <63936253+ichard26@users.noreply.github.com>
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
