Introduce "project root" as a concept

[etc/vim.git] / black.py

diff --git a/black.py b/black.py
index 05ec00c8f25944756f8f2f21e66df0a8d2568d8b..730c64de0b1883ff42e906d90d6985d4ddec9b51 100644 (file)
--- a/black.py
+++ b/black.py
@@ -2,7 +2,7 @@ import asyncio
 import pickle
 from asyncio.base_events import BaseEventLoop
 from concurrent.futures import Executor, ProcessPoolExecutor
 import pickle
 from asyncio.base_events import BaseEventLoop
 from concurrent.futures import Executor, ProcessPoolExecutor

-from enum import Enum
+from enum import Enum, Flag

 from functools import partial, wraps
 import keyword
 import logging
 from functools import partial, wraps
 import keyword
 import logging


@@ -44,8 +44,12 @@ from blib2to3.pgen2 import driver, token
 from blib2to3.pgen2.parse import ParseError
 
 
 from blib2to3.pgen2.parse import ParseError
 
 

-__version__ = "18.5b0"
+__version__ = "18.5b1"

 DEFAULT_LINE_LENGTH = 88
 DEFAULT_LINE_LENGTH = 88

+DEFAULT_EXCLUDES = (
+    r"/(\.git|\.hg|\.mypy_cache|\.tox|\.venv|_build|buck-out|build|dist)/"
+)
+DEFAULT_INCLUDES = r"\.pyi?$"

 CACHE_DIR = Path(user_cache_dir("black", version=__version__))
 
 
 CACHE_DIR = Path(user_cache_dir("black", version=__version__))
 
 


@@ -122,6 +126,13 @@ class Changed(Enum):
     YES = 2
 
 
     YES = 2
 
 

+class FileMode(Flag):
+    AUTO_DETECT = 0
+    PYTHON36 = 1
+    PYI = 2
+    NO_STRING_NORMALIZATION = 4
+
+

 @click.command()
 @click.option(
     "-l",
 @click.command()
 @click.option(
     "-l",


@@ -131,6 +142,29 @@ class Changed(Enum):
     help="How many character per line to allow.",
     show_default=True,
 )
     help="How many character per line to allow.",
     show_default=True,
 )

+@click.option(
+    "--py36",
+    is_flag=True,
+    help=(
+        "Allow using Python 3.6-only syntax on all input files.  This will put "
+        "trailing commas in function signatures and calls also after *args and "
+        "**kwargs.  [default: per-file auto-detection]"
+    ),
+)
+@click.option(
+    "--pyi",
+    is_flag=True,
+    help=(
+        "Format all input files like typing stubs regardless of file extension "
+        "(useful when piping source on standard input)."
+    ),
+)
+@click.option(
+    "-S",
+    "--skip-string-normalization",
+    is_flag=True,
+    help="Don't normalize string quotes or prefixes.",
+)

 @click.option(
     "--check",
     is_flag=True,
 @click.option(
     "--check",
     is_flag=True,


@@ -151,29 +185,37 @@ class Changed(Enum):
     help="If --fast given, skip temporary sanity checks. [default: --safe]",
 )
 @click.option(
     help="If --fast given, skip temporary sanity checks. [default: --safe]",
 )
 @click.option(

-    "-q",
-    "--quiet",
-    is_flag=True,
+    "--include",
+    type=str,
+    default=DEFAULT_INCLUDES,

     help=(
     help=(

-        "Don't emit non-error messages to stderr. Errors are still emitted, "
-        "silence those with 2>/dev/null."
+        "A regular expression that matches files and directories that should be "
+        "included on recursive searches.  An empty value means all files are "
+        "included regardless of the name.  Use forward slashes for directories on "
+        "all platforms (Windows, too).  Exclusions are calculated first, inclusions "
+        "later."

     ),
     ),

+    show_default=True,

 )
 @click.option(
 )
 @click.option(

-    "--pyi",
-    is_flag=True,
+    "--exclude",
+    type=str,
+    default=DEFAULT_EXCLUDES,

     help=(
     help=(

-        "Consider all input files typing stubs regardless of file extension "
-        "(useful when piping source on standard input)."
+        "A regular expression that matches files and directories that should be "
+        "excluded on recursive searches.  An empty value means no paths are excluded. "
+        "Use forward slashes for directories on all platforms (Windows, too).  "
+        "Exclusions are calculated first, inclusions later."

     ),
     ),

+    show_default=True,

 )
 @click.option(
 )
 @click.option(

-    "--py36",
+    "-q",
+    "--quiet",

     is_flag=True,
     help=(
     is_flag=True,
     help=(

-        "Allow using Python 3.6-only syntax on all input files.  This will put "
-        "trailing commas in function signatures and calls also after *args and "
-        "**kwargs.  [default: per-file auto-detection]"
+        "Don't emit non-error messages to stderr. Errors are still emitted, "
+        "silence those with 2>/dev/null."

     ),
 )
 @click.version_option(version=__version__)
     ),
 )
 @click.version_option(version=__version__)


@@ -193,15 +235,31 @@ def main(
     fast: bool,
     pyi: bool,
     py36: bool,
     fast: bool,
     pyi: bool,
     py36: bool,

+    skip_string_normalization: bool,

     quiet: bool,
     quiet: bool,

+    include: str,
+    exclude: str,

     src: List[str],
 ) -> None:
     """The uncompromising code formatter."""
     sources: List[Path] = []
     src: List[str],
 ) -> None:
     """The uncompromising code formatter."""
     sources: List[Path] = []

+    try:
+        include_regex = re.compile(include)
+    except re.error:
+        err(f"Invalid regular expression for include given: {include!r}")
+        ctx.exit(2)
+    try:
+        exclude_regex = re.compile(exclude)
+    except re.error:
+        err(f"Invalid regular expression for exclude given: {exclude!r}")
+        ctx.exit(2)
+    root = find_project_root(src)

     for s in src:
         p = Path(s)
         if p.is_dir():
     for s in src:
         p = Path(s)
         if p.is_dir():

-            sources.extend(gen_python_files_in_dir(p))
+            sources.extend(
+                gen_python_files_in_dir(p, root, include_regex, exclude_regex)
+            )

         elif p.is_file():
             # if a file was explicitly given, we don't care about its extension
             sources.append(p)
         elif p.is_file():
             # if a file was explicitly given, we don't care about its extension
             sources.append(p)


@@ -216,6 +274,13 @@ def main(
         write_back = WriteBack.DIFF
     else:
         write_back = WriteBack.YES
         write_back = WriteBack.DIFF
     else:
         write_back = WriteBack.YES

+    mode = FileMode.AUTO_DETECT
+    if py36:
+        mode |= FileMode.PYTHON36
+    if pyi:
+        mode |= FileMode.PYI
+    if skip_string_normalization:
+        mode |= FileMode.NO_STRING_NORMALIZATION

     report = Report(check=check, quiet=quiet)
     if len(sources) == 0:
         out("No paths given. Nothing to do 😴")
     report = Report(check=check, quiet=quiet)
     if len(sources) == 0:
         out("No paths given. Nothing to do 😴")


@@ -227,9 +292,8 @@ def main(
             src=sources[0],
             line_length=line_length,
             fast=fast,
             src=sources[0],
             line_length=line_length,
             fast=fast,

-            pyi=pyi,
-            py36=py36,

             write_back=write_back,
             write_back=write_back,

+            mode=mode,

             report=report,
         )
     else:
             report=report,
         )
     else:


@@ -241,9 +305,8 @@ def main(
                     sources=sources,
                     line_length=line_length,
                     fast=fast,
                     sources=sources,
                     line_length=line_length,
                     fast=fast,

-                    pyi=pyi,
-                    py36=py36,

                     write_back=write_back,
                     write_back=write_back,

+                    mode=mode,

                     report=report,
                     loop=loop,
                     executor=executor,
                     report=report,
                     loop=loop,
                     executor=executor,


@@ -261,9 +324,8 @@ def reformat_one(
     src: Path,
     line_length: int,
     fast: bool,
     src: Path,
     line_length: int,
     fast: bool,

-    pyi: bool,
-    py36: bool,

     write_back: WriteBack,
     write_back: WriteBack,

+    mode: FileMode,

     report: "Report",
 ) -> None:
     """Reformat a single file under `src` without spawning child processes.
     report: "Report",
 ) -> None:
     """Reformat a single file under `src` without spawning child processes.


@@ -276,31 +338,26 @@ def reformat_one(
         changed = Changed.NO
         if not src.is_file() and str(src) == "-":
             if format_stdin_to_stdout(
         changed = Changed.NO
         if not src.is_file() and str(src) == "-":
             if format_stdin_to_stdout(

-                line_length=line_length,
-                fast=fast,
-                is_pyi=pyi,
-                force_py36=py36,
-                write_back=write_back,
+                line_length=line_length, fast=fast, write_back=write_back, mode=mode

             ):
                 changed = Changed.YES
         else:
             cache: Cache = {}
             if write_back != WriteBack.DIFF:
             ):
                 changed = Changed.YES
         else:
             cache: Cache = {}
             if write_back != WriteBack.DIFF:

-                cache = read_cache(line_length, pyi, py36)
-                src = src.resolve()
-                if src in cache and cache[src] == get_cache_info(src):
+                cache = read_cache(line_length, mode)
+                res_src = src.resolve()
+                if res_src in cache and cache[res_src] == get_cache_info(res_src):

                     changed = Changed.CACHED
             if changed is not Changed.CACHED and format_file_in_place(
                 src,
                 line_length=line_length,
                 fast=fast,
                     changed = Changed.CACHED
             if changed is not Changed.CACHED and format_file_in_place(
                 src,
                 line_length=line_length,
                 fast=fast,

-                force_pyi=pyi,
-                force_py36=py36,

                 write_back=write_back,
                 write_back=write_back,

+                mode=mode,

             ):
                 changed = Changed.YES
             if write_back == WriteBack.YES and changed is not Changed.NO:
             ):
                 changed = Changed.YES
             if write_back == WriteBack.YES and changed is not Changed.NO:

-                write_cache(cache, [src], line_length, pyi, py36)
+                write_cache(cache, [src], line_length, mode)

         report.done(src, changed)
     except Exception as exc:
         report.failed(src, str(exc))
         report.done(src, changed)
     except Exception as exc:
         report.failed(src, str(exc))


@@ -310,9 +367,8 @@ async def schedule_formatting(
     sources: List[Path],
     line_length: int,
     fast: bool,
     sources: List[Path],
     line_length: int,
     fast: bool,

-    pyi: bool,
-    py36: bool,

     write_back: WriteBack,
     write_back: WriteBack,

+    mode: FileMode,

     report: "Report",
     loop: BaseEventLoop,
     executor: Executor,
     report: "Report",
     loop: BaseEventLoop,
     executor: Executor,


@@ -326,7 +382,7 @@ async def schedule_formatting(
     """
     cache: Cache = {}
     if write_back != WriteBack.DIFF:
     """
     cache: Cache = {}
     if write_back != WriteBack.DIFF:

-        cache = read_cache(line_length, pyi, py36)
+        cache = read_cache(line_length, mode)

         sources, cached = filter_cached(cache, sources)
         for src in cached:
             report.done(src, Changed.CACHED)
         sources, cached = filter_cached(cache, sources)
         for src in cached:
             report.done(src, Changed.CACHED)


@@ -346,9 +402,8 @@ async def schedule_formatting(
                 src,
                 line_length,
                 fast,
                 src,
                 line_length,
                 fast,

-                pyi,
-                py36,

                 write_back,
                 write_back,

+                mode,

                 lock,
             ): src
             for src in sorted(sources)
                 lock,
             ): src
             for src in sorted(sources)


@@ -374,16 +429,15 @@ async def schedule_formatting(
     if cancelled:
         await asyncio.gather(*cancelled, loop=loop, return_exceptions=True)
     if write_back == WriteBack.YES and formatted:
     if cancelled:
         await asyncio.gather(*cancelled, loop=loop, return_exceptions=True)
     if write_back == WriteBack.YES and formatted:

-        write_cache(cache, formatted, line_length, pyi, py36)
+        write_cache(cache, formatted, line_length, mode)

 
 
 def format_file_in_place(
     src: Path,
     line_length: int,
     fast: bool,
 
 
 def format_file_in_place(
     src: Path,
     line_length: int,
     fast: bool,

-    force_pyi: bool = False,
-    force_py36: bool = False,

     write_back: WriteBack = WriteBack.NO,
     write_back: WriteBack = WriteBack.NO,

+    mode: FileMode = FileMode.AUTO_DETECT,

     lock: Any = None,  # multiprocessing.Manager().Lock() is some crazy proxy
 ) -> bool:
     """Format file under `src` path. Return True if changed.
     lock: Any = None,  # multiprocessing.Manager().Lock() is some crazy proxy
 ) -> bool:
     """Format file under `src` path. Return True if changed.


@@ -391,17 +445,13 @@ def format_file_in_place(
     If `write_back` is True, write reformatted code back to stdout.
     `line_length` and `fast` options are passed to :func:`format_file_contents`.
     """
     If `write_back` is True, write reformatted code back to stdout.
     `line_length` and `fast` options are passed to :func:`format_file_contents`.
     """

-    is_pyi = force_pyi or src.suffix == ".pyi"
-
+    if src.suffix == ".pyi":
+        mode |= FileMode.PYI

     with tokenize.open(src) as src_buffer:
         src_contents = src_buffer.read()
     try:
         dst_contents = format_file_contents(
     with tokenize.open(src) as src_buffer:
         src_contents = src_buffer.read()
     try:
         dst_contents = format_file_contents(

-            src_contents,
-            line_length=line_length,
-            fast=fast,
-            is_pyi=is_pyi,
-            force_py36=force_py36,
+            src_contents, line_length=line_length, fast=fast, mode=mode

         )
     except NothingChanged:
         return False
         )
     except NothingChanged:
         return False


@@ -426,9 +476,8 @@ def format_file_in_place(
 def format_stdin_to_stdout(
     line_length: int,
     fast: bool,
 def format_stdin_to_stdout(
     line_length: int,
     fast: bool,

-    is_pyi: bool = False,
-    force_py36: bool = False,

     write_back: WriteBack = WriteBack.NO,
     write_back: WriteBack = WriteBack.NO,

+    mode: FileMode = FileMode.AUTO_DETECT,

 ) -> bool:
     """Format file on stdin. Return True if changed.
 
 ) -> bool:
     """Format file on stdin. Return True if changed.
 


@@ -439,13 +488,7 @@ def format_stdin_to_stdout(
     src = sys.stdin.read()
     dst = src
     try:
     src = sys.stdin.read()
     dst = src
     try:

-        dst = format_file_contents(
-            src,
-            line_length=line_length,
-            fast=fast,
-            is_pyi=is_pyi,
-            force_py36=force_py36,
-        )
+        dst = format_file_contents(src, line_length=line_length, fast=fast, mode=mode)

         return True
 
     except NothingChanged:
         return True
 
     except NothingChanged:


@@ -465,8 +508,7 @@ def format_file_contents(
     *,
     line_length: int,
     fast: bool,
     *,
     line_length: int,
     fast: bool,

-    is_pyi: bool = False,
-    force_py36: bool = False,
+    mode: FileMode = FileMode.AUTO_DETECT,

 ) -> FileContent:
     """Reformat contents a file and return new contents.
 
 ) -> FileContent:
     """Reformat contents a file and return new contents.
 


@@ -477,30 +519,18 @@ def format_file_contents(
     if src_contents.strip() == "":
         raise NothingChanged
 
     if src_contents.strip() == "":
         raise NothingChanged
 

-    dst_contents = format_str(
-        src_contents, line_length=line_length, is_pyi=is_pyi, force_py36=force_py36
-    )
+    dst_contents = format_str(src_contents, line_length=line_length, mode=mode)

     if src_contents == dst_contents:
         raise NothingChanged
 
     if not fast:
         assert_equivalent(src_contents, dst_contents)
     if src_contents == dst_contents:
         raise NothingChanged
 
     if not fast:
         assert_equivalent(src_contents, dst_contents)

-        assert_stable(
-            src_contents,
-            dst_contents,
-            line_length=line_length,
-            is_pyi=is_pyi,
-            force_py36=force_py36,
-        )
+        assert_stable(src_contents, dst_contents, line_length=line_length, mode=mode)

     return dst_contents
 
 
 def format_str(
     return dst_contents
 
 
 def format_str(

-    src_contents: str,
-    line_length: int,
-    *,
-    is_pyi: bool = False,
-    force_py36: bool = False,
+    src_contents: str, line_length: int, *, mode: FileMode = FileMode.AUTO_DETECT

 ) -> FileContent:
     """Reformat a string and return new contents.
 
 ) -> FileContent:
     """Reformat a string and return new contents.
 


@@ -509,11 +539,15 @@ def format_str(
     src_node = lib2to3_parse(src_contents)
     dst_contents = ""
     future_imports = get_future_imports(src_node)
     src_node = lib2to3_parse(src_contents)
     dst_contents = ""
     future_imports = get_future_imports(src_node)

-    elt = EmptyLineTracker(is_pyi=is_pyi)
-    py36 = force_py36 or is_python36(src_node)
+    is_pyi = bool(mode & FileMode.PYI)
+    py36 = bool(mode & FileMode.PYTHON36) or is_python36(src_node)
+    normalize_strings = not bool(mode & FileMode.NO_STRING_NORMALIZATION)

     lines = LineGenerator(
     lines = LineGenerator(

-        remove_u_prefix=py36 or "unicode_literals" in future_imports, is_pyi=is_pyi
+        remove_u_prefix=py36 or "unicode_literals" in future_imports,
+        is_pyi=is_pyi,
+        normalize_strings=normalize_strings,

     )
     )

+    elt = EmptyLineTracker(is_pyi=is_pyi)

     empty_line = Line()
     after = 0
     for current_line in lines.visit(src_node):
     empty_line = Line()
     after = 0
     for current_line in lines.visit(src_node):


@@ -987,6 +1021,15 @@ class Line:
             and self.leaves[3].value == ")"
         )
 
             and self.leaves[3].value == ")"
         )
 

+    @property
+    def is_triple_quoted_string(self) -> bool:
+        """Is the line a triple quoted string?"""
+        return (
+            bool(self)
+            and self.leaves[0].type == token.STRING
+            and self.leaves[0].value.startswith(('"""', "'''"))
+        )
+

     def contains_standalone_comments(self, depth_limit: int = sys.maxsize) -> bool:
         """If so, needs to be split before emitting."""
         for leaf in self.leaves:
     def contains_standalone_comments(self, depth_limit: int = sys.maxsize) -> bool:
         """If so, needs to be split before emitting."""
         for leaf in self.leaves:


@@ -1194,6 +1237,7 @@ class EmptyLineTracker:
     the prefix of the first leaf consists of optional newlines.  Those newlines
     are consumed by `maybe_empty_lines()` and included in the computation.
     """
     the prefix of the first leaf consists of optional newlines.  Those newlines
     are consumed by `maybe_empty_lines()` and included in the computation.
     """

+

     is_pyi: bool = False
     previous_line: Optional[Line] = None
     previous_after: int = 0
     is_pyi: bool = False
     previous_line: Optional[Line] = None
     previous_after: int = 0


@@ -1244,6 +1288,11 @@ class EmptyLineTracker:
             if self.previous_line.is_decorator:
                 return 0, 0
 
             if self.previous_line.is_decorator:
                 return 0, 0
 

+            if self.previous_line.depth < current_line.depth and (
+                self.previous_line.is_class or self.previous_line.is_def
+            ):
+                return 0, 0
+

             if (
                 self.previous_line.is_comment
                 and self.previous_line.depth == current_line.depth
             if (
                 self.previous_line.is_comment
                 and self.previous_line.depth == current_line.depth


@@ -1275,6 +1324,13 @@ class EmptyLineTracker:
         ):
             return (before or 1), 0
 
         ):
             return (before or 1), 0
 

+        if (
+            self.previous_line
+            and self.previous_line.is_class
+            and current_line.is_triple_quoted_string
+        ):
+            return before, 1
+

         return before, 0
 
 
         return before, 0
 
 


@@ -1285,7 +1341,9 @@ class LineGenerator(Visitor[Line]):
     Note: destroys the tree it's visiting by mutating prefixes of its leaves
     in ways that will no longer stringify to valid Python code on the tree.
     """
     Note: destroys the tree it's visiting by mutating prefixes of its leaves
     in ways that will no longer stringify to valid Python code on the tree.
     """

+

     is_pyi: bool = False
     is_pyi: bool = False

+    normalize_strings: bool = True

     current_line: Line = Factory(Line)
     remove_u_prefix: bool = False
 
     current_line: Line = Factory(Line)
     remove_u_prefix: bool = False
 


@@ -1354,7 +1412,7 @@ class LineGenerator(Visitor[Line]):
 
             else:
                 normalize_prefix(node, inside_brackets=any_open_brackets)
 
             else:
                 normalize_prefix(node, inside_brackets=any_open_brackets)

-                if node.type == token.STRING:
+                if self.normalize_strings and node.type == token.STRING:

                     normalize_string_prefix(node, remove_u_prefix=self.remove_u_prefix)
                     normalize_string_quotes(node)
                 if node.type not in WHITESPACE:
                     normalize_string_prefix(node, remove_u_prefix=self.remove_u_prefix)
                     normalize_string_quotes(node)
                 if node.type not in WHITESPACE:


@@ -2736,38 +2794,63 @@ def get_future_imports(node: Node) -> Set[str]:
     return imports
 
 
     return imports
 
 

-PYTHON_EXTENSIONS = {".py", ".pyi"}
-BLACKLISTED_DIRECTORIES = {
-    "build",
-    "buck-out",
-    "dist",
-    "_build",
-    ".git",
-    ".hg",
-    ".mypy_cache",
-    ".tox",
-    ".venv",
-}
-
-
-def gen_python_files_in_dir(path: Path) -> Iterator[Path]:
-    """Generate all files under `path` which aren't under BLACKLISTED_DIRECTORIES
-    and have one of the PYTHON_EXTENSIONS.
+def gen_python_files_in_dir(
+    path: Path, root: Path, include: Pattern[str], exclude: Pattern[str]
+) -> Iterator[Path]:
+    """Generate all files under `path` whose paths are not excluded by the
+    `exclude` regex, but are included by the `include` regex.

     """
     """

+    assert root.is_absolute(), f"INTERNAL ERROR: `root` must be absolute but is {root}"

     for child in path.iterdir():
     for child in path.iterdir():

+        normalized_path = child.resolve().relative_to(root).as_posix()

         if child.is_dir():
         if child.is_dir():

-            if child.name in BLACKLISTED_DIRECTORIES:
-                continue
+            normalized_path += "/"
+        exclude_match = exclude.search(normalized_path)
+        if exclude_match and exclude_match.group(0):
+            continue
+
+        if child.is_dir():
+            yield from gen_python_files_in_dir(child, root, include, exclude)

 
 

-            yield from gen_python_files_in_dir(child)
+        elif child.is_file():
+            include_match = include.search(normalized_path)
+            if include_match:
+                yield child

 
 

-        elif child.is_file() and child.suffix in PYTHON_EXTENSIONS:
-            yield child
+
+def find_project_root(srcs: List[str]) -> Path:
+    """Return a directory containing .git, .hg, or pyproject.toml.
+
+    That directory can be one of the directories passed in `srcs` or their
+    common parent.
+
+    If no directory in the tree contains a marker that would specify it's the
+    project root, the root of the file system is returned.
+    """
+    if not srcs:
+        return Path("/").resolve()
+
+    common_base = min(Path(src).resolve() for src in srcs)
+    if common_base.is_dir():
+        # Append a fake file so `parents` below returns `common_base_dir`, too.
+        common_base /= "fake-file"
+    for directory in common_base.parents:
+        if (directory / ".git").is_dir():
+            return directory
+
+        if (directory / ".hg").is_dir():
+            return directory
+
+        if (directory / "pyproject.toml").is_file():
+            return directory
+
+    return directory

 
 
 @dataclass
 class Report:
     """Provides a reformatting counter. Can be rendered with `str(report)`."""
 
 
 @dataclass
 class Report:
     """Provides a reformatting counter. Can be rendered with `str(report)`."""

+

     check: bool = False
     quiet: bool = False
     change_count: int = 0
     check: bool = False
     quiet: bool = False
     change_count: int = 0


@@ -2908,12 +2991,10 @@ def assert_equivalent(src: str, dst: str) -> None:
 
 
 def assert_stable(
 
 
 def assert_stable(

-    src: str, dst: str, line_length: int, is_pyi: bool = False, force_py36: bool = False
+    src: str, dst: str, line_length: int, mode: FileMode = FileMode.AUTO_DETECT

 ) -> None:
     """Raise AssertionError if `dst` reformats differently the second time."""
 ) -> None:
     """Raise AssertionError if `dst` reformats differently the second time."""

-    newdst = format_str(
-        dst, line_length=line_length, is_pyi=is_pyi, force_py36=force_py36
-    )
+    newdst = format_str(dst, line_length=line_length, mode=mode)

     if dst != newdst:
         log = dump_to_file(
             diff(src, dst, "source", "first pass"),
     if dst != newdst:
         log = dump_to_file(
             diff(src, dst, "source", "first pass"),


@@ -3124,19 +3205,21 @@ def can_omit_invisible_parens(line: Line, line_length: int) -> bool:
     return False
 
 
     return False
 
 

-def get_cache_file(line_length: int, pyi: bool = False, py36: bool = False) -> Path:
+def get_cache_file(line_length: int, mode: FileMode) -> Path:
+    pyi = bool(mode & FileMode.PYI)
+    py36 = bool(mode & FileMode.PYTHON36)

     return (
         CACHE_DIR
         / f"cache.{line_length}{'.pyi' if pyi else ''}{'.py36' if py36 else ''}.pickle"
     )
 
 
     return (
         CACHE_DIR
         / f"cache.{line_length}{'.pyi' if pyi else ''}{'.py36' if py36 else ''}.pickle"
     )
 
 

-def read_cache(line_length: int, pyi: bool = False, py36: bool = False) -> Cache:
+def read_cache(line_length: int, mode: FileMode) -> Cache:

     """Read the cache if it exists and is well formed.
 
     If it is not well formed, the call to write_cache later should resolve the issue.
     """
     """Read the cache if it exists and is well formed.
 
     If it is not well formed, the call to write_cache later should resolve the issue.
     """

-    cache_file = get_cache_file(line_length, pyi, py36)
+    cache_file = get_cache_file(line_length, mode)

     if not cache_file.exists():
         return {}
 
     if not cache_file.exists():
         return {}
 


@@ -3174,14 +3257,10 @@ def filter_cached(
 
 
 def write_cache(
 
 
 def write_cache(

-    cache: Cache,
-    sources: List[Path],
-    line_length: int,
-    pyi: bool = False,
-    py36: bool = False,
+    cache: Cache, sources: List[Path], line_length: int, mode: FileMode

 ) -> None:
     """Update the cache file."""
 ) -> None:
     """Update the cache file."""

-    cache_file = get_cache_file(line_length, pyi, py36)
+    cache_file = get_cache_file(line_length, mode)

     try:
         if not CACHE_DIR.exists():
             CACHE_DIR.mkdir(parents=True)
     try:
         if not CACHE_DIR.exists():
             CACHE_DIR.mkdir(parents=True)