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>
As discussed in #1441, Python 3.9's new parser will not parse
`(*starred)` even using `compile()` with the `PyCF_ONLY_AST`
flag (as `ast.parse()` does), it raises a `SyntaxError`. This
breaks the four tests that use this file with Python 3.9.
Upstream does not consider this to be a bug - see
https://bugs.python.org/issue40848#msg370643 - so we must
adjust the expression. As suggested by @JelleZijlstra, this just
adds a comma, which makes the new parser happy with it (the old
parser is fine with this form also).
Signed-off-by: Adam Williamson <awilliam@redhat.com>
* Re-indent the contents of docstrings when indentation changes
Keeping the contents of docstrings completely unchanged when
re-indenting (from 2-space intents to 4, for example) can cause
incorrect docstring indentation:
```
class MyClass:
"""Multiline
class docstring
"""
def method(self):
"""Multiline
method docstring
"""
pass
```
...becomes:
```
class MyClass:
"""Multiline
class docstring
"""
def method(self):
"""Multiline
method docstring
"""
pass
```
This uses the PEP 257 algorithm for determining docstring indentation,
and adjusts the contents of docstrings to match their new indentation
after `black` is applied.
A small normalization is necessary to `assert_equivalent` because the
trees are technically no longer precisely equivalent -- some constant
strings have changed. When comparing two ASTs, whitespace after
newlines within constant strings is thus folded into a single space.
Co-authored-by: Luka Zakrajšek <luka@bancek.net>
* Extract the inner `_v` method to decrease complexity
This reduces the cyclomatic complexity to a level that makes flake8 happy.
* Blacken blib2to3's docstring which had an over-indent
Co-authored-by: Luka Zakrajšek <luka@bancek.net>
Co-authored-by: Zsolt Dollenstein <zsol.zsol@gmail.com>
This pull request's main intention is to wraps long strings (as requested by #182); however, it also provides better string handling in general and, in doing so, closes the following issues:
Closes#26Closes#182Closes#933Closes#1183Closes#1243
`split("\n")` includes a final empty element `""` if the final line
ends with `\n` (as it should for POSIX-compliant text files), which
then became an extra `"\n"`.
`splitlines()` solves that, but there's a caveat, as it will split
on other types of line breaks too (like `\r`), which may not be
desired.
Fixes#526.
`type: ignore` shouldn't block collapsing a line, since it will still
apply fine to the merged line. This prevents an issue where a reformat
causes it to shift lines and then be merged on a subsequent pass.
There is a downside to this, which is that it can cause a `type:
ignore` to apply to more code than was originally intended. There
might be a way to apply this in a more limited situation, but I'm not
sure what it is.
Fixes#1061.
The old behavior would detect the existence of a `# fmt: on` in a leaf
node's comment prefix and immediately mark the node as formatting-on,
even if a subsequent `# fmt: off` in the same comment prefix would turn
it back off. This change modifies that logic to track the state through
the entire prefix and take the final state.
Note that this does not fully solve on/off behavior, since any _comment_
lines between the off/on are still formatted. We may need to add
virtual leaf nodes to truly solve that. I will leave that for a separate
commit/PR.
Fixes#1005
Fixes#1042 (and probably #1044 which looks like the same thing).
The issue with the "obviously unnecessary" parentheses that #850 removed is that sometimes they're necessary to help Black fit something in one line. I didn't see an obvious solution that still removes the parens #850 was intended to remove, so let's back out this change for now in the interest of unblocking a release.
This PR also adds a test adapted from the failing example in #1042, so that if we try to reapply the #850 change we don't break the same case again.
It turns out we also need to handle invisible *left* parens added at
the *start* of a line. Refactor `contains_unsplittable_type_ignore` to
handle this more cleanly.
* add test for special unicode symbol which usual re can not process correctly
add regex lib which supports unicode 12.1.0 standard
replace re usage in project in favor to regex
* #455 fix dependency
In #1040 I had convinced myself that the type ignore logic didn't
need anything like the ignored_ids from the type comment logic, but I
was wrong, and we do.
We hit these cases in practice a bunch.
The code introduced in #1027 to detect whether a type comment appeared
after a regular comment in a Line would spuriously misfire when a leaf
was in the comments dict but had an empty list of comments. This can
occur as an artifact of how comments on trailing commas are handled,
it seems.
(This was discovered trying to test black out on mypy.)
Type comments only apply if they are the first comment on the line,
which means that allowing them to be pushed behind a regular comment
when joining lines is a semantic change (and, indeed, one that black
catches and fails on).
* Parse `:=` properly
* never unwrap parenthesis around `:=`
* When checking for AST-equivalence, use `ast` instead of `typed-ast` when running on python >=3.8
* Assume code that uses `:=` is at least 3.8
Modified maybe_remove_trailing_comma to remove trailing commas for
typedarglists (in addition to arglists), and updated line split logic
to ensure that all lines in a function definition that contain only one
arg have a trailing comma.
Based on the feedback in
https://github.com/python/black/pull/845#issuecomment-490622711
- Remove TokenizerConfig, and add a field to Grammar instead.
- Pass the Grammar to the tokenizer.
- Rename `ASYNC_IS_RESERVED_KEYWORD` to `ASYNC_KEYWORDS` and
`ASYNC_IS_VALID_IDENTIFIER` to `ASYNC_IDENTIFIERS`.
Fixes#593
I looked into this bug with @ambv and @carljm, and we reached the
conclusion was that it's not possible for the tokenizer to determine if
async/await is a keyword inside all possible generators without breaking
the grammar for older versions of Python.
Instead, we introduce a new tokenizer mode for Python 3.7+ that will
cause all async/await instances to get parsed as a reserved keyword,
which should fix async/await inside generators.
This is a new syntax added in python3.7, so black can't verify that reformatting will not change the ast unless black itself is run with 3.7. We'll need to change the error message black gives in this case. @ambv any ideas?
Fixes#125.
Fixes#452
I ended up making a couple of other normalizations to numeric literals
too (lowercase everything, don't allow leading or trailing . in floats,
remove redundant + sign in exponent). I don't care too much about those,
so I'm happy to change the behavior there.
For reference, here is Python's grammar for numeric literals:
https://docs.python.org/3/reference/lexical_analysis.html#numeric-literals
