merge remote main

CHANGES.md

@@ -11,6 +11,8 @@
 <!-- Changes that affect Black's stable style -->
 
 - Collapse multiple lines into 1 after import (#4488)
+- Fix formatting cells in IPython notebooks with magic methods and starting or trailing
+  empty lines (#4484)
 
 ### Preview style
 

gallery/gallery.py

@@ -10,7 +10,7 @@
 from concurrent.futures import ThreadPoolExecutor
 from functools import lru_cache, partial
 from pathlib import Path
-from typing import Generator, List, NamedTuple, Optional, Tuple, Union, cast
+from typing import Generator, NamedTuple, Optional, Union, cast
 from urllib.request import urlopen, urlretrieve
 
 PYPI_INSTANCE = "https://pypi.org/pypi"
@@ -54,7 +54,7 @@ def get_pypi_download_url(package: str, version: Optional[str]) -> str:
     return cast(str, source["url"])
 
 
-def get_top_packages() -> List[str]:
+def get_top_packages() -> list[str]:
     with urlopen(PYPI_TOP_PACKAGES) as page:
         result = json.load(page)
 
@@ -150,7 +150,7 @@ def git_switch_branch(
     subprocess.run(args, cwd=repo)
 
 
-def init_repos(options: Namespace) -> Tuple[Path, ...]:
+def init_repos(options: Namespace) -> tuple[Path, ...]:
     options.output.mkdir(exist_ok=True)
 
     if options.top_packages:
@@ -206,7 +206,7 @@ def format_repo_with_version(
     git_switch_branch(black_version.version, repo=black_repo)
     git_switch_branch(current_branch, repo=repo, new=True, from_branch=from_branch)
 
-    format_cmd: List[Union[Path, str]] = [
+    format_cmd: list[Union[Path, str]] = [
         black_runner(black_version.version, black_repo),
         (black_repo / "black.py").resolve(),
         ".",
@@ -222,7 +222,7 @@ def format_repo_with_version(
     return current_branch
 
 
-def format_repos(repos: Tuple[Path, ...], options: Namespace) -> None:
+def format_repos(repos: tuple[Path, ...], options: Namespace) -> None:
     black_versions = tuple(
         BlackVersion(*version.split(":")) for version in options.versions
     )

scripts/make_width_table.py

@@ -18,12 +18,12 @@
 
 import sys
 from os.path import basename, dirname, join
-from typing import Iterable, Tuple
+from typing import Iterable
 
 import wcwidth  # type: ignore[import-not-found]
 
 
-def make_width_table() -> Iterable[Tuple[int, int, int]]:
+def make_width_table() -> Iterable[tuple[int, int, int]]:
     start_codepoint = -1
     end_codepoint = -1
     range_width = -2
@@ -53,9 +53,9 @@ def main() -> None:
         f.write(f"""# Generated by {basename(__file__)}
 # wcwidth {wcwidth.__version__}
 # Unicode {wcwidth.list_versions()[-1]}
-from typing import Final, List, Tuple
+from typing import Final
 
-WIDTH_TABLE: Final[List[Tuple[int, int, int]]] = [
+WIDTH_TABLE: Final[list[tuple[int, int, int]]] = [
 """)
         for triple in make_width_table():
             f.write(f"    {triple!r},\n")

src/black/handle_ipynb_magics.py

@@ -178,12 +178,14 @@ def mask_cell(src: str) -> tuple[str, list[Replacement]]:
     from IPython.core.inputtransformer2 import TransformerManager
 
     transformer_manager = TransformerManager()
+    # A side effect of the following transformation is that it also removes any
+    # empty lines at the beginning of the cell.
     transformed = transformer_manager.transform_cell(src)
     transformed, cell_magic_replacements = replace_cell_magics(transformed)
     replacements += cell_magic_replacements
     transformed = transformer_manager.transform_cell(transformed)
     transformed, magic_replacements = replace_magics(transformed)
-    if len(transformed.splitlines()) != len(src.splitlines()):
+    if len(transformed.strip().splitlines()) != len(src.strip().splitlines()):
         # Multi-line magic, not supported.
         raise NothingChanged
     replacements += magic_replacements
@@ -269,7 +271,7 @@ def replace_magics(src: str) -> tuple[str, list[Replacement]]:
     magic_finder = MagicFinder()
     magic_finder.visit(ast.parse(src))
     new_srcs = []
-    for i, line in enumerate(src.splitlines(), start=1):
+    for i, line in enumerate(src.split("\n"), start=1):
         if i in magic_finder.magics:
             offsets_and_magics = magic_finder.magics[i]
             if len(offsets_and_magics) != 1:  # pragma: nocover

tests/optional.py

@@ -18,7 +18,7 @@
 import logging
 import re
 from functools import lru_cache
-from typing import TYPE_CHECKING, FrozenSet, List, Set
+from typing import TYPE_CHECKING
 
 import pytest
 
@@ -46,8 +46,8 @@
     from _pytest.nodes import Node
 
 
-ALL_POSSIBLE_OPTIONAL_MARKERS = StashKey[FrozenSet[str]]()
-ENABLED_OPTIONAL_MARKERS = StashKey[FrozenSet[str]]()
+ALL_POSSIBLE_OPTIONAL_MARKERS = StashKey[frozenset[str]]()
+ENABLED_OPTIONAL_MARKERS = StashKey[frozenset[str]]()
 
 
 def pytest_addoption(parser: "Parser") -> None:
@@ -69,7 +69,7 @@ def pytest_configure(config: "Config") -> None:
     """
     ot_ini = config.inicfg.get("optional-tests") or []
     ot_markers = set()
-    ot_run: Set[str] = set()
+    ot_run: set[str] = set()
     if isinstance(ot_ini, str):
         ot_ini = ot_ini.strip().split("\n")
     marker_re = re.compile(r"^\s*(?P<no>no_)?(?P<marker>\w+)(:\s*(?P<description>.*))?")
@@ -103,7 +103,7 @@ def pytest_configure(config: "Config") -> None:
     store[ENABLED_OPTIONAL_MARKERS] = frozenset(ot_run)
 
 
-def pytest_collection_modifyitems(config: "Config", items: "List[Node]") -> None:
+def pytest_collection_modifyitems(config: "Config", items: "list[Node]") -> None:
     store = config._store
     all_possible_optional_markers = store[ALL_POSSIBLE_OPTIONAL_MARKERS]
     enabled_optional_markers = store[ENABLED_OPTIONAL_MARKERS]
@@ -120,7 +120,7 @@ def pytest_collection_modifyitems(config: "Config", items: "List[Node]") -> None
 
 
 @lru_cache
-def skip_mark(tests: FrozenSet[str]) -> "MarkDecorator":
+def skip_mark(tests: frozenset[str]) -> "MarkDecorator":
     names = ", ".join(sorted(tests))
     return pytest.mark.skip(reason=f"Marked with disabled optional tests ({names})")
 

tests/test_black.py

@@ -17,19 +17,7 @@
 from pathlib import Path, WindowsPath
 from platform import system
 from tempfile import TemporaryDirectory
-from typing import (
-    Any,
-    Callable,
-    Dict,
-    Iterator,
-    List,
-    Optional,
-    Sequence,
-    Set,
-    Type,
-    TypeVar,
-    Union,
-)
+from typing import Any, Callable, Iterator, Optional, Sequence, TypeVar, Union
 from unittest.mock import MagicMock, patch
 
 import click
@@ -107,11 +95,11 @@ class FakeContext(click.Context):
     """A fake click Context for when calling functions that need it."""
 
     def __init__(self) -> None:
-        self.default_map: Dict[str, Any] = {}
-        self.params: Dict[str, Any] = {}
+        self.default_map: dict[str, Any] = {}
+        self.params: dict[str, Any] = {}
         self.command: click.Command = black.main
         # Dummy root, since most of the tests don't care about it
-        self.obj: Dict[str, Any] = {"root": PROJECT_ROOT}
+        self.obj: dict[str, Any] = {"root": PROJECT_ROOT}
 
 
 class FakeParameter(click.Parameter):
@@ -129,7 +117,7 @@ def __init__(self) -> None:
 
 
 def invokeBlack(
-    args: List[str], exit_code: int = 0, ignore_config: bool = True
+    args: list[str], exit_code: int = 0, ignore_config: bool = True
 ) -> None:
     runner = BlackRunner()
     if ignore_config:
@@ -933,7 +921,7 @@ def test_get_features_used(self) -> None:
             "with ((a, ((b as c)))): pass", {Feature.PARENTHESIZED_CONTEXT_MANAGERS}
         )
 
-    def check_features_used(self, source: str, expected: Set[Feature]) -> None:
+    def check_features_used(self, source: str, expected: set[Feature]) -> None:
         node = black.lib2to3_parse(source)
         actual = black.get_features_used(node)
         msg = f"Expected {expected} but got {actual} for {source!r}"
@@ -1365,7 +1353,7 @@ def test_reformat_one_with_stdin_empty(self) -> None:
         ]
 
         def _new_wrapper(
-            output: io.StringIO, io_TextIOWrapper: Type[io.TextIOWrapper]
+            output: io.StringIO, io_TextIOWrapper: type[io.TextIOWrapper]
         ) -> Callable[[Any, Any], io.TextIOWrapper]:
             def get_output(*args: Any, **kwargs: Any) -> io.TextIOWrapper:
                 if args == (sys.stdout.buffer,):
@@ -2350,7 +2338,7 @@ def test_read_cache_line_lengths(self) -> None:
     def test_cache_key(self) -> None:
         # Test that all members of the mode enum affect the cache key.
         for field in fields(Mode):
-            values: List[Any]
+            values: list[Any]
             if field.name == "target_versions":
                 values = [
                     {TargetVersion.PY312},
@@ -2463,7 +2451,7 @@ def test_gitignore_exclude(self) -> None:
         gitignore = PathSpec.from_lines(
             "gitwildmatch", ["exclude/", ".definitely_exclude"]
         )
-        sources: List[Path] = []
+        sources: list[Path] = []
         expected = [
             Path(path / "b/dont_exclude/a.py"),
             Path(path / "b/dont_exclude/a.pyi"),
@@ -2491,7 +2479,7 @@ def test_nested_gitignore(self) -> None:
         exclude = re.compile(r"")
         root_gitignore = black.files.get_gitignore(path)
         report = black.Report()
-        expected: List[Path] = [
+        expected: list[Path] = [
             Path(path / "x.py"),
             Path(path / "root/b.py"),
             Path(path / "root/c.py"),

tests/test_docs.py

@@ -7,7 +7,7 @@
 import re
 from itertools import islice
 from pathlib import Path
-from typing import Optional, Sequence, Set
+from typing import Optional, Sequence
 
 import pytest
 
@@ -17,7 +17,7 @@
 
 
 def check_feature_list(
-    lines: Sequence[str], expected_feature_names: Set[str], label: str
+    lines: Sequence[str], expected_feature_names: set[str], label: str
 ) -> Optional[str]:
     start_index = lines.index(f"(labels/{label}-features)=\n")
     if start_index == -1:

tests/test_ipynb.py

@@ -173,6 +173,22 @@ def test_cell_magic_with_magic() -> None:
     assert result == expected
 
 
+@pytest.mark.parametrize(
+    "src, expected",
+    (
+        ("\n\n\n%time \n\n", "%time"),
+        ("  \n\t\n%%timeit -n4 \t \nx=2  \n\r\n", "%%timeit -n4\nx = 2"),
+        (
+            "  \t\n\n%%capture \nx=2 \n%config \n\n%env\n\t  \n \n\n",
+            "%%capture\nx = 2\n%config\n\n%env",
+        ),
+    ),
+)
+def test_cell_magic_with_empty_lines(src: str, expected: str) -> None:
+    result = format_cell(src, fast=True, mode=JUPYTER_MODE)
+    assert result == expected
+
+
 @pytest.mark.parametrize(
     "mode, expected_output, expectation",
     [

tests/test_ranges.py

@@ -1,7 +1,5 @@
 """Test the black.ranges module."""
 
-from typing import List, Tuple
-
 import pytest
 
 from black.ranges import adjusted_lines, sanitized_lines
@@ -11,7 +9,7 @@
     "lines",
     [[(1, 1)], [(1, 3)], [(1, 1), (3, 4)]],
 )
-def test_no_diff(lines: List[Tuple[int, int]]) -> None:
+def test_no_diff(lines: list[tuple[int, int]]) -> None:
     source = """\
 import re
 
@@ -32,7 +30,7 @@ def func():
         [(0, 8), (3, 1)],
     ],
 )
-def test_invalid_lines(lines: List[Tuple[int, int]]) -> None:
+def test_invalid_lines(lines: list[tuple[int, int]]) -> None:
     original_source = """\
 import re
 def foo(arg):
@@ -83,7 +81,7 @@ def func(arg1, arg2, arg3):
     ],
 )
 def test_removals(
-    lines: List[Tuple[int, int]], adjusted: List[Tuple[int, int]]
+    lines: list[tuple[int, int]], adjusted: list[tuple[int, int]]
 ) -> None:
     original_source = """\
 1. first line
@@ -118,7 +116,7 @@ def test_removals(
     ],
 )
 def test_additions(
-    lines: List[Tuple[int, int]], adjusted: List[Tuple[int, int]]
+    lines: list[tuple[int, int]], adjusted: list[tuple[int, int]]
 ) -> None:
     original_source = """\
 1. first line
@@ -154,7 +152,7 @@ def test_additions(
         ([(9, 10), (1, 1)], [(1, 1), (9, 9)]),
     ],
 )
-def test_diffs(lines: List[Tuple[int, int]], adjusted: List[Tuple[int, int]]) -> None:
+def test_diffs(lines: list[tuple[int, int]], adjusted: list[tuple[int, int]]) -> None:
     original_source = """\
  1. import re
  2. def foo(arg):
@@ -231,7 +229,7 @@ def test_diffs(lines: List[Tuple[int, int]], adjusted: List[Tuple[int, int]]) ->
     ],
 )
 def test_sanitize(
-    lines: List[Tuple[int, int]], sanitized: List[Tuple[int, int]]
+    lines: list[tuple[int, int]], sanitized: list[tuple[int, int]]
 ) -> None:
     source = """\
 1. import re

tests/test_tokenize.py

@@ -4,7 +4,6 @@
 import sys
 import textwrap
 from dataclasses import dataclass
-from typing import List
 
 import black
 from blib2to3.pgen2 import token, tokenize
@@ -18,10 +17,10 @@ class Token:
     end: tokenize.Coord
 
 
-def get_tokens(text: str) -> List[Token]:
+def get_tokens(text: str) -> list[Token]:
     """Return the tokens produced by the tokenizer."""
     readline = io.StringIO(text).readline
-    tokens: List[Token] = []
+    tokens: list[Token] = []
 
     def tokeneater(
         type: int, string: str, start: tokenize.Coord, end: tokenize.Coord, line: str
@@ -32,7 +31,7 @@ def tokeneater(
     return tokens
 
 
-def assert_tokenizes(text: str, tokens: List[Token]) -> None:
+def assert_tokenizes(text: str, tokens: list[Token]) -> None:
     """Assert that the tokenizer produces the expected tokens."""
     actual_tokens = get_tokens(text)
     assert actual_tokens == tokens

tests/test_trans.py

@@ -1,11 +1,9 @@
-from typing import List, Tuple
-
 from black.trans import iter_fexpr_spans
 
 
 def test_fexpr_spans() -> None:
     def check(
-        string: str, expected_spans: List[Tuple[int, int]], expected_slices: List[str]
+        string: str, expected_spans: list[tuple[int, int]], expected_slices: list[str]
     ) -> None:
         spans = list(iter_fexpr_spans(string))