"""
Generating lines of code.
"""
-from functools import partial, wraps
import sys
+from functools import partial, wraps
from typing import Collection, Iterator, List, Optional, Set, Union, cast
-from black.nodes import WHITESPACE, RARROW, STATEMENT, STANDALONE_COMMENT
-from black.nodes import ASSIGNMENTS, OPENING_BRACKETS, CLOSING_BRACKETS
-from black.nodes import Visitor, syms, is_arith_like, ensure_visible
+from black.brackets import COMMA_PRIORITY, DOT_PRIORITY, max_delimiter_priority_in_atom
+from black.comments import FMT_OFF, generate_comments, list_comments
+from black.lines import (
+ Line,
+ append_leaves,
+ can_be_split,
+ can_omit_invisible_parens,
+ is_line_short_enough,
+ line_to_string,
+)
+from black.mode import Feature, Mode, Preview
from black.nodes import (
+ ASSIGNMENTS,
+ CLOSING_BRACKETS,
+ OPENING_BRACKETS,
+ RARROW,
+ STANDALONE_COMMENT,
+ STATEMENT,
+ WHITESPACE,
+ Visitor,
+ ensure_visible,
+ is_arith_like,
+ is_atom_with_invisible_parens,
is_docstring,
is_empty_tuple,
- is_one_tuple,
+ is_lpar_token,
+ is_multiline_string,
+ is_name_token,
is_one_sequence_between,
+ is_one_tuple,
+ is_rpar_token,
+ is_stub_body,
+ is_stub_suite,
+ is_vararg,
+ is_walrus_assignment,
+ is_yield,
+ syms,
+ wrap_in_parentheses,
)
-from black.nodes import is_name_token, is_lpar_token, is_rpar_token
-from black.nodes import is_walrus_assignment, is_yield, is_vararg, is_multiline_string
-from black.nodes import is_stub_suite, is_stub_body, is_atom_with_invisible_parens
-from black.nodes import wrap_in_parentheses
-from black.brackets import max_delimiter_priority_in_atom
-from black.brackets import DOT_PRIORITY, COMMA_PRIORITY
-from black.lines import Line, line_to_string, is_line_short_enough
-from black.lines import can_omit_invisible_parens, can_be_split, append_leaves
-from black.comments import generate_comments, list_comments, FMT_OFF
from black.numerics import normalize_numeric_literal
-from black.strings import get_string_prefix, fix_docstring
-from black.strings import normalize_string_prefix, normalize_string_quotes
-from black.trans import Transformer, CannotTransform, StringMerger, StringSplitter
-from black.trans import StringParenWrapper, StringParenStripper, hug_power_op
-from black.mode import Mode, Feature, Preview
-
-from blib2to3.pytree import Node, Leaf
+from black.strings import (
+ fix_docstring,
+ get_string_prefix,
+ normalize_string_prefix,
+ normalize_string_quotes,
+)
+from black.trans import (
+ CannotTransform,
+ StringMerger,
+ StringParenStripper,
+ StringParenWrapper,
+ StringSplitter,
+ Transformer,
+ hug_power_op,
+)
from blib2to3.pgen2 import token
-
+from blib2to3.pytree import Leaf, Node
# types
LeafID = int
for child in children:
yield from self.visit(child)
- if child.type == token.ASYNC:
+ if child.type == token.ASYNC or child.type == STANDALONE_COMMENT:
+ # STANDALONE_COMMENT happens when `# fmt: skip` is applied on the async
+ # line.
break
internal_stmt = next(children)
if is_docstring(leaf) and "\\\n" not in leaf.value:
# We're ignoring docstrings with backslash newline escapes because changing
# indentation of those changes the AST representation of the code.
- docstring = normalize_string_prefix(leaf.value)
+ if Preview.normalize_docstring_quotes_and_prefixes_properly in self.mode:
+ # There was a bug where --skip-string-normalization wouldn't stop us
+ # from normalizing docstring prefixes. To maintain stability, we can
+ # only address this buggy behaviour while the preview style is enabled.
+ if self.mode.string_normalization:
+ docstring = normalize_string_prefix(leaf.value)
+ # visit_default() does handle string normalization for us, but
+ # since this method acts differently depending on quote style (ex.
+ # see padding logic below), there's a possibility for unstable
+ # formatting as visit_default() is called *after*. To avoid a
+ # situation where this function formats a docstring differently on
+ # the second pass, normalize it early.
+ docstring = normalize_string_quotes(docstring)
+ else:
+ docstring = leaf.value
+ else:
+ # ... otherwise, we'll keep the buggy behaviour >.<
+ docstring = normalize_string_prefix(leaf.value)
prefix = get_string_prefix(docstring)
docstring = docstring[len(prefix) :] # Remove the prefix
quote_char = docstring[0]
quote_len = 1 if docstring[1] != quote_char else 3
docstring = docstring[quote_len:-quote_len]
docstring_started_empty = not docstring
+ indent = " " * 4 * self.current_line.depth
if is_multiline_string(leaf):
- indent = " " * 4 * self.current_line.depth
docstring = fix_docstring(docstring, indent)
else:
docstring = docstring.strip()
# We could enforce triple quotes at this point.
quote = quote_char * quote_len
- leaf.value = prefix + quote + docstring + quote
+
+ # It's invalid to put closing single-character quotes on a new line.
+ if Preview.long_docstring_quotes_on_newline in self.mode and quote_len == 3:
+ # We need to find the length of the last line of the docstring
+ # to find if we can add the closing quotes to the line without
+ # exceeding the maximum line length.
+ # If docstring is one line, then we need to add the length
+ # of the indent, prefix, and starting quotes. Ending quotes are
+ # handled later.
+ lines = docstring.splitlines()
+ last_line_length = len(lines[-1]) if docstring else 0
+
+ if len(lines) == 1:
+ last_line_length += len(indent) + len(prefix) + quote_len
+
+ # If adding closing quotes would cause the last line to exceed
+ # the maximum line length then put a line break before the
+ # closing quotes
+ if last_line_length + quote_len > self.mode.line_length:
+ leaf.value = prefix + quote + docstring + "\n" + indent + quote
+ else:
+ leaf.value = prefix + quote + docstring + quote
+ else:
+ leaf.value = prefix + quote + docstring + quote
yield from self.visit_default(leaf)