Black would previously strip the parenthesis away from statements like this these ones:
assert (spam := 12 + 1)
return (cheese := 1 - 12)
Which happens to be invalid code. Now before making the parenthesis invisible, Black
checks if the assignment expression's parent is an assert stamtment, aborting if True.
Raise, yield, and await are already handled fine.
I added a bunch of test cases from the PEP defining asssignment expressions (PEP 572).
Optional trailing commas put by Black become magic trailing commas on another
pass of the tool. Since they are influencing formatting around optional
parentheses, on rare occasions the tool changes its mind in terms of putting
parentheses or not.
Ideally this would never be the case but sadly the decision to put optional
parentheses or not (which looks at pre-existing "magic" trailing commas) is
happening around the same time as the decision to put an optional trailing
comma. Untangling the two proved to be impractically difficult.
This shameful workaround uses the fact that the formatting instability
introduced by magic trailing commas is deterministic: if the optional trailing
comma becoming a pre-existing "magic" trailing comma changes formatting, the
second pass becomes stable since there is no variable factor anymore on pass 3,
4, and so on.
For most files, this will introduce no performance penalty since `--safe` is
already re-formatting everything twice to ensure formatting stability. We're
using this result and if all's good, the behavior is equivalent. If there is
a difference, we treat the second result as the binding one, and check its
sanity again.
Fixes#1738. Fixes#1812.
Previously, Black removed leading and trailing spaces in multiline docstrings but failed to remove them from one-line docstrings.
* Added support for top-level user configuration
At the user level, a TOML config can be specified in the following locations:
* Windows: ~\.black
* Unix-like: $XDG_CONFIG_HOME/black (~/.config/black fallback)
Instead of changing env vars for the entire black-primer process, they
are now changed only for the black subprocess, using a tmpdir.
Fixes: #1662
Work-around for https://bugs.python.org/issue2142
The test has to slightly mess with its input data, because the utility
functions default to ensuring the test data has a final newline, which
defeats the point of the test.
Signed-off-by: Paul "TBBle" Hampson <Paul.Hampson@Pobox.com>
* Add test case to illustrate the issue
* Accept carriage returns as valid separators while enumerating comments
Without this acceptance, escaped multi-line statments that use carriage returns will not be counted into the 'ignored_lines' variable since the emitted line values will end with a CR and not an escape character. That leads to comments associated with the line being incorrectly labeled with the STANDALONE_COMMENT type, affecting comment placement and line space management.
* Remove comment linking to ephemeral build log
* Provide a stdin-filename to allow stdin to respect exclude/force-exclude rules
This will allow automatic tools to enforce the project's
exclude/force-exclude rules even if they pass the file through stdin to
update its buffer.
This is a similar solution to --stdin-display-name in flake8.
* Update src/black/__init__.py
Co-authored-by: Richard Si <63936253+ichard26@users.noreply.github.com>
* --stdin-filename should only respect --exclude-filename
* Update README with the new --stdin-filename option
* Write some tests for the new stdin-filename functionality
* Apply suggestions from code review
Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com>
* Force stdin output when we asked for stdin even if the file exists
* Add an entry in the changelog regarding --stdin-filename
* Reduce disk reads if possible
Co-authored-by: Richard Si <63936253+ichard26@users.noreply.github.com>
* Check for is_stdin and p.is_file before checking for p.is_dir()
Co-authored-by: Richard Si <63936253+ichard26@users.noreply.github.com>
Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com>
The `fix_docstring` function expanded all tabs, which caused a
difference in the AST representation when those tabs were inline and not
leading. This changes the function to only expand leading tabs so inline
tabs are preserved.
Fixes#1601.
Black used to erroneously remove all empty lines between non-function
code and decorators when formatting typing stubs. Now a single empty
line is enforced.
I chose for putting empty lines around decorated classes that have empty
bodies since removing empty lines around such classes would cause a
formatting issue that seems to be impossible to fix.
For example:
```
class A: ...
@some_decorator
class B: ...
class C: ...
class D: ...
@some_other_decorator
def foo(): -> None: ...
```
It is easy to enforce no empty lines between class A, B, and C.
Just return 0, 0 for a line that is a decorator and precedes an stub
class. Fortunately before this commit, empty lines after that class
would be removed already.
Now let's look at the empty line between class D and function foo. In
this case, there should be an empty line there since it's class code next
to function code. The problem is that when deciding to add X empty lines
before a decorator, you can't tell whether it's before a class or a
function. If the decorator is before a function, then an empty line
is needed, while no empty lines are needed when the decorator is
before a class.
So even though I personally prefer no empty lines around decorated
classes, I had to go the other way surrounding decorated classes with
empty lines.
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
* Fix incorrect space before colon in if/while stmts
Previously Black would format this code
```
if (foo := True):
print(foo)
```
as
```
if (foo := True) :
print(foo)
```
adding an incorrect space after the RPAR. Buggy code in the
normalize_invisible_parens function caused the colon to be wrapped in
invisible parentheses. The LPAR of that pair was then prefixed with a
single space at the request of the whitespace function.
This commit fixes the accidental skipping of a pre-condition check
which must return True before parenthesis normalization of a specific
child Leaf or Node can happen. The pre-condition check being skipped
was why the colon was wrapped in invisible parentheses.
* Add an entry in CHANGES.md
The quotes of multiline docstrings are now only normalized when string
normalization is off, instead of the string normalization setting being
ignored and the quotes being *always* normalized.
I had to make a new test case and data file since the current pair for
docstrings only worked when there is no formatting difference between the
formatting results with string normalization on and off. I needed to add
tests for when there *are* differences between the two. So I split
test_docstring's test code when string normalization is disabled into a
new test case along with a new data file.
This addresses a few crashers, namely:
* producing non-equivalent code due to mangling escaped newlines,
* invalid hugging quote characters in the docstring body to the docstring outer
triple quotes (causing a quadruple quote which is a syntax error),
* lack of handling for docstrings that start on the same line as the `def`, and
* invalid stripping of outer triple quotes when the docstring contained
a string prefix.
As a bonus, tests now also run when string normalization is disabled.
This required some hackery. Long story short, we need to reuse the ability to
omit rightmost bracket pairs (which glues them together and splits on something
else instead), for use with pre-existing trailing commas.
This form of user-controlled formatting is brittle so we have to be careful not
to cause a scenario where Black first formats code without trailing commas in
one way, and then looks at the same file with pre-existing trailing commas
(that it itself put on the previous run) and decides to format the code again.
One particular ugly edge case here is handling of optional parentheses. In
particular, the long-standing `line_length=1` hack got in the way of
pre-existing trailing commas and had to be removed. Instead, a more
intelligent but costly solution was put in place: a "second opinion" if the
formatting that omits optional parentheses ended up causing lines to be too
long. Again, for efficiency purposes, Black reuses Leaf objects from blib2to3
and modifies them in place, which was invalid for having two separate
formattings. Line cloning was used to mitigate this.
Fixes#1619
- when a trailing comma is specified in any bracket pair, that signals to Black
that this bracket pair needs to be always exploded, e.g. presented as "one
item per line";
- this causes some changes to previously formatted code that erroneously left
trailing commas embedded into single-line expressions;
- internally, Black needs to be able to identify trailing commas that it put
itself compared to pre-existing trailing commas. We do this by using/abusing
lib2to3's `was_checked` attribute. It's True for internally generated
trailing commas and False for pre-existing ones (in fact, for all
pre-existing leaves and nodes).
Fixes#1288
* put experimental string stuff behind a flag
* update tests
* don't need an output section if it's the same as the input
* Primer: Expect no formatting changes in attrs, hypothesis and poetry with --experimental-string-processing off
Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com>
