Update Contributing Docs (#1915)

[etc/vim.git] / src / black / __init__.py

diff --git a/src/black/__init__.py b/src/black/__init__.py
index 44edeb0d9f1a0c09d4be1e2aee383a677d59f821..91f70d96165748741583ce2d7b94007b71111f87 100644 (file)
--- a/src/black/__init__.py
+++ b/src/black/__init__.py
@@ -42,7 +42,6 @@ from typing import (
     cast,
     TYPE_CHECKING,
 )
-from typing_extensions import Final
 from mypy_extensions import mypyc_attr
 
 from appdirs import user_cache_dir
@@ -61,6 +60,11 @@ from blib2to3.pgen2.parse import ParseError
 
 from _black_version import version as __version__
 
+if sys.version_info < (3, 8):
+    from typing_extensions import Final
+else:
+    from typing import Final
+
 if TYPE_CHECKING:
     import colorama  # noqa: F401
 
@@ -68,6 +72,7 @@ DEFAULT_LINE_LENGTH = 88
 DEFAULT_EXCLUDES = r"/(\.direnv|\.eggs|\.git|\.hg|\.mypy_cache|\.nox|\.tox|\.venv|\.svn|_build|buck-out|build|dist)/"  # noqa: B950
 DEFAULT_INCLUDES = r"\.pyi?$"
 CACHE_DIR = Path(user_cache_dir("black", version=__version__))
+STDIN_PLACEHOLDER = "__BLACK_STDIN_FILENAME__"
 
 STRING_PREFIX_CHARS: Final = "furbFURB"  # All possible string prefix characters.
 
@@ -457,6 +462,15 @@ def target_version_option_callback(
         "excluded even when they are passed explicitly as arguments."
     ),
 )
+@click.option(
+    "--stdin-filename",
+    type=str,
+    help=(
+        "The name of the file when passing it through stdin. Useful to make "
+        "sure Black will respect --force-exclude option on some "
+        "editors that rely on using stdin."
+    ),
+)
 @click.option(
     "-q",
     "--quiet",
@@ -516,6 +530,7 @@ def main(
     include: str,
     exclude: str,
     force_exclude: Optional[str],
+    stdin_filename: Optional[str],
     src: Tuple[str, ...],
     config: Optional[str],
 ) -> None:
@@ -548,6 +563,7 @@ def main(
         exclude=exclude,
         force_exclude=force_exclude,
         report=report,
+        stdin_filename=stdin_filename,
     )
 
     path_empty(
@@ -587,6 +603,7 @@ def get_sources(
     exclude: str,
     force_exclude: Optional[str],
     report: "Report",
+    stdin_filename: Optional[str],
 ) -> Set[Path]:
     """Compute the set of files to be formatted."""
     try:
@@ -613,22 +630,14 @@ def get_sources(
     gitignore = get_gitignore(root)
 
     for s in src:
-        p = Path(s)
-        if p.is_dir():
-            sources.update(
-                gen_python_files(
-                    p.iterdir(),
-                    root,
-                    include_regex,
-                    exclude_regex,
-                    force_exclude_regex,
-                    report,
-                    gitignore,
-                )
-            )
-        elif s == "-":
-            sources.add(p)
-        elif p.is_file():
+        if s == "-" and stdin_filename:
+            p = Path(stdin_filename)
+            is_stdin = True
+        else:
+            p = Path(s)
+            is_stdin = False
+
+        if is_stdin or p.is_file():
             normalized_path = normalize_path_maybe_ignore(p, root, report)
             if normalized_path is None:
                 continue
@@ -643,6 +652,23 @@ def get_sources(
                 report.path_ignored(p, "matches the --force-exclude regular expression")
                 continue
 
+            if is_stdin:
+                p = Path(f"{STDIN_PLACEHOLDER}{str(p)}")
+
+            sources.add(p)
+        elif p.is_dir():
+            sources.update(
+                gen_python_files(
+                    p.iterdir(),
+                    root,
+                    include_regex,
+                    exclude_regex,
+                    force_exclude_regex,
+                    report,
+                    gitignore,
+                )
+            )
+        elif s == "-":
             sources.add(p)
         else:
             err(f"invalid path: {s}")
@@ -670,7 +696,18 @@ def reformat_one(
     """
     try:
         changed = Changed.NO
-        if not src.is_file() and str(src) == "-":
+
+        if str(src) == "-":
+            is_stdin = True
+        elif str(src).startswith(STDIN_PLACEHOLDER):
+            is_stdin = True
+            # Use the original name again in case we want to print something
+            # to the user
+            src = Path(str(src)[len(STDIN_PLACEHOLDER) :])
+        else:
+            is_stdin = False
+
+        if is_stdin:
             if format_stdin_to_stdout(fast=fast, write_back=write_back, mode=mode):
                 changed = Changed.YES
         else:
@@ -704,7 +741,7 @@ def reformat_many(
     worker_count = os.cpu_count()
     if sys.platform == "win32":
         # Work around https://bugs.python.org/issue26903
-        worker_count = min(worker_count, 61)
+        worker_count = min(worker_count, 60)
     try:
         executor = ProcessPoolExecutor(max_workers=worker_count)
     except (ImportError, OSError):
@@ -953,7 +990,7 @@ def format_str(src_contents: str, *, mode: Mode) -> FileContent:
     allowed.  Example:
 
     >>> import black
-    >>> print(black.format_str("def f(arg:str='')->None:...", mode=Mode()))
+    >>> print(black.format_str("def f(arg:str='')->None:...", mode=black.Mode()))
     def f(arg: str = "") -> None:
         ...
 
@@ -3238,7 +3275,8 @@ class StringParenStripper(StringTransformer):
 
     Requirements:
         The line contains a string which is surrounded by parentheses and:
-            - The target string is NOT the only argument to a function call).
+            - The target string is NOT the only argument to a function call.
+            - The target string is NOT a "pointless" string.
             - If the target string contains a PERCENT, the brackets are not
               preceeded or followed by an operator with higher precedence than
               PERCENT.
@@ -3262,6 +3300,14 @@ class StringParenStripper(StringTransformer):
             if leaf.type != token.STRING:
                 continue
 
+            # If this is a "pointless" string...
+            if (
+                leaf.parent
+                and leaf.parent.parent
+                and leaf.parent.parent.type == syms.simple_stmt
+            ):
+                continue
+
             # Should be preceded by a non-empty LPAR...
             if (
                 not is_valid_index(idx - 1)