Resolves#2168 by disabling the insertion of a " " when the docstring is entirely empty.
Note that this PR is focussed only on the case of empty docstrings. In particular this does not make any changes to the behaviour that a " " is inserted if a non-empty docstring begins with the quoting character. That is, black still prefers:
""" "something" """
to:
""""something" """
and that:
""""Something""""
is not a legal docstring.
Fixes#1738. Fixes#1812.
Previously, Black removed leading and trailing spaces in multiline docstrings but failed to remove them from one-line docstrings.
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.
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.
* 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>
