Change linter to Ruff (#30)

Author: Schamper

dissect/squashfs/__init__.py

@@ -10,10 +10,10 @@
 __all__ = [
     "Error",
     "FileNotFoundError",
+    "FileStream",
+    "INode",
     "NotADirectoryError",
     "NotAFileError",
     "NotASymlinkError",
-    "FileStream",
-    "INode",
     "SquashFS",
 ]

dissect/squashfs/c_squashfs.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import stat
 
 from dissect.cstruct import cstruct

dissect/squashfs/compression.py

@@ -1,12 +1,11 @@
 from __future__ import annotations
 
 import importlib
-from typing import Optional
 
 from dissect.squashfs.c_squashfs import c_squashfs
 
 
-def initialize(id: int, options: Optional[bytes]) -> Compression:
+def initialize(id: int, options: bytes | None) -> Compression:
     # Options have no effect on decompression, so ignore for now
     modules = {
         c_squashfs.ZLIB_COMPRESSION: (NativeZlib,),
@@ -21,10 +20,10 @@ def initialize(id: int, options: Optional[bytes]) -> Compression:
         for mod in modules[id]:
             try:
                 return mod()
-            except ModuleNotFoundError:
+            except ModuleNotFoundError:  # noqa: PERF203
                 pass
         else:
-            raise ImportError(f"No modules available ({modules[id]})")
+            raise ImportError(f"No modules available ({modules[id]})")  # noqa: TRY301
     except ImportError:
         raise ValueError(f"Compression ID {id} requested but module ({modules[id]}) is not available")
     except KeyError:
@@ -38,10 +37,10 @@ def __init__(self):
         self._module = importlib.import_module(self.module)
 
     def compress(self, data: bytes) -> bytes:
-        raise NotImplementedError()
+        raise NotImplementedError
 
     def decompress(self, data: bytes, expected: int) -> bytes:
-        raise NotImplementedError()
+        raise NotImplementedError
 
 
 class NativeZlib(Compression):

dissect/squashfs/squashfs.py

@@ -7,9 +7,8 @@
 import stat
 import struct
 from bisect import bisect_right
-from datetime import datetime
 from functools import cache, cached_property, lru_cache
-from typing import BinaryIO, Iterator, Optional, Union
+from typing import TYPE_CHECKING, BinaryIO
 
 from dissect.util import ts
 from dissect.util.stream import RunlistStream
@@ -23,6 +22,10 @@
     NotASymlinkError,
 )
 
+if TYPE_CHECKING:
+    from collections.abc import Iterator
+    from datetime import datetime
+
 
 class SquashFS:
     def __init__(self, fh: BinaryIO):
@@ -68,15 +71,15 @@ def inode(
         self,
         block: int,
         offset: int,
-        name: Optional[str] = None,
-        type: Optional[int] = None,
-        inode_number: Optional[int] = None,
-        parent: Optional[INode] = None,
+        name: str | None = None,
+        type: int | None = None,
+        inode_number: int | None = None,
+        parent: INode | None = None,
     ) -> INode:
         # squashfs inode numbers consist of a block number and offset in that block
         return INode(self, block, offset, name, type, inode_number, parent)
 
-    def get(self, path: Union[str, int], node: Optional[INode] = None) -> INode:
+    def get(self, path: str | int, node: INode | None = None) -> INode:
         if isinstance(path, int):
             return self.inode(path >> 16, path & 0xFFFF)
 
@@ -135,7 +138,7 @@ def _read_metadata(self, block: int, offset: int, length: int) -> tuple[int, int
 
         return block, offset, b"".join(result)
 
-    def _read_block(self, block: int, length: Optional[int] = None) -> tuple[int, bytes]:
+    def _read_block(self, block: int, length: int | None = None) -> tuple[int, bytes]:
         if length is not None:
             # Data block
             compressed = length & c_squashfs.SQUASHFS_COMPRESSED_BIT_BLOCK == 0
@@ -177,13 +180,12 @@ def _lookup_inode(self, inode_number: int) -> INode:
         _, _, data = self._read_metadata(self.lookup_table[block], offset, 8)
         return self.get(struct.unpack("<Q", data)[0])
 
-    def _lookup_fragment(self, fragment: int) -> bytes:
+    def _lookup_fragment(self, fragment: int) -> c_squashfs.squashfs_fragment_entry:
         fragment_offset = fragment * len(c_squashfs.squashfs_fragment_entry)
         block, offset = divmod(fragment_offset, c_squashfs.SQUASHFS_METADATA_SIZE)
 
         _, _, data = self._read_metadata(self.fragment_table[block], offset, len(c_squashfs.squashfs_fragment_entry))
-        entry = c_squashfs.squashfs_fragment_entry(data)
-        return entry
+        return c_squashfs.squashfs_fragment_entry(data)
 
     def iter_inodes(self) -> Iterator[INode]:
         for inum in range(1, self.sb.inodes + 1):
@@ -196,10 +198,10 @@ def __init__(
         fs: SquashFS,
         block: int,
         offset: int,
-        name: Optional[str] = None,
-        type: Optional[int] = None,
-        inode_number: Optional[int] = None,
-        parent: Optional[INode] = None,
+        name: str | None = None,
+        type: int | None = None,
+        inode_number: int | None = None,
+        parent: INode | None = None,
     ):
         self.fs = fs
         self.block = block
@@ -209,6 +211,8 @@ def __init__(
         self._inode_number = inode_number
         self.parent = parent
 
+        self.listdir = cache(self.listdir)
+
     def __repr__(self) -> str:
         return f"<inode {self.inode_number} ({self.block}, {self.offset})>"
 
@@ -220,15 +224,9 @@ def _metadata(
         | c_squashfs.squashfs_reg_inode_header
         | c_squashfs.squashfs_symlink_inode_header
         | c_squashfs.squashfs_dev_inode_header
-        | c_squashfs.squashfs_dev_inode_header
-        | c_squashfs.squashfs_base_inode_header
-        | c_squashfs.squashfs_base_inode_header
         | c_squashfs.squashfs_ldir_inode_header
         | c_squashfs.squashfs_lreg_inode_header
-        | c_squashfs.squashfs_symlink_inode_header
-        | c_squashfs.squashfs_ldev_inode_header
         | c_squashfs.squashfs_ldev_inode_header
-        | c_squashfs.squashfs_lipc_inode_header
         | c_squashfs.squashfs_lipc_inode_header,
         int,
         int,
@@ -262,16 +260,10 @@ def header(
         | c_squashfs.squashfs_reg_inode_header
         | c_squashfs.squashfs_symlink_inode_header
         | c_squashfs.squashfs_dev_inode_header
-        | c_squashfs.squashfs_dev_inode_header
-        | c_squashfs.squashfs_base_inode_header
-        | c_squashfs.squashfs_base_inode_header
         | c_squashfs.squashfs_ldir_inode_header
         | c_squashfs.squashfs_lreg_inode_header
-        | c_squashfs.squashfs_symlink_inode_header
-        | c_squashfs.squashfs_ldev_inode_header
         | c_squashfs.squashfs_ldev_inode_header
         | c_squashfs.squashfs_lipc_inode_header
-        | c_squashfs.squashfs_lipc_inode_header
     ):
         header, _, _ = self._metadata()
         return header
@@ -315,11 +307,12 @@ def mtime(self) -> datetime:
         return ts.from_unix(self.header.mtime)
 
     @property
-    def size(self) -> Optional[int]:
+    def size(self) -> int | None:
         if self.is_dir() or self.is_file():
             return self.header.file_size
-        elif self.is_symlink():
+        if self.is_symlink():
             return self.header.symlink_size
+        return None
 
     def is_dir(self) -> bool:
         return self.type == stat.S_IFDIR
@@ -363,13 +356,9 @@ def link(self) -> str:
     @cached_property
     def link_inode(self) -> INode:
         link = self.link
-        if link.startswith("/"):
-            relnode = None
-        else:
-            relnode = self.parent
+        relnode = None if link.startswith("/") else self.parent
         return self.fs.get(self.link, relnode)
 
-    @cache
     def listdir(self) -> dict[str, INode]:
         return {inode.name: inode for inode in self.iterdir()}
 
@@ -407,7 +396,7 @@ def iterdir(self) -> Iterator[INode]:
                 )
 
     @cached_property
-    def block_list(self) -> list[tuple[Optional[int], int]]:
+    def block_list(self) -> list[tuple[int | None, int]]:
         fragment = self.header.fragment
         file_size = self.header.file_size
         if fragment == c_squashfs.SQUASHFS_INVALID_FRAG:

pyproject.toml

@@ -53,13 +53,56 @@ dev = [
     "dissect.util>=3.0.dev,<4.0.dev",
 ]
 
-[tool.black]
+[tool.ruff]
 line-length = 120
+required-version = ">=0.9.0"
 
-[tool.isort]
-profile = "black"
-known_first_party = ["dissect.squashfs"]
-known_third_party = ["dissect"]
+[tool.ruff.format]
+docstring-code-format = true
+
+[tool.ruff.lint]
+select = [
+  "F",
+  "E",
+  "W",
+  "I",
+  "UP",
+  "YTT",
+  "ANN",
+  "B",
+  "C4",
+  "DTZ",
+  "T10",
+  "FA",
+  "ISC",
+  "G",
+  "INP",
+  "PIE",
+  "PYI",
+  "PT",
+  "Q",
+  "RSE",
+  "RET",
+  "SLOT",
+  "SIM",
+  "TID",
+  "TCH",
+  "PTH",
+  "PLC",
+  "TRY",
+  "FLY",
+  "PERF",
+  "FURB",
+  "RUF",
+]
+ignore = ["E203", "B904", "UP024", "ANN002", "ANN003", "ANN204", "ANN401", "SIM105", "TRY003"]
+
+[tool.ruff.lint.per-file-ignores]
+"tests/docs/**" = ["INP001"]
+
+[tool.ruff.lint.isort]
+known-first-party = ["dissect.squashfs"]
+known-third-party = ["dissect"]
 
 [tool.setuptools]
 license-files = ["LICENSE", "COPYRIGHT"]

tests/conftest.py

@@ -1,53 +1,59 @@
+from __future__ import annotations
+
 import gzip
-import os
+from pathlib import Path
+from typing import TYPE_CHECKING, BinaryIO
 
 import pytest
 
+if TYPE_CHECKING:
+    from collections.abc import Iterator
+
 
-def absolute_path(filename):
-    return os.path.join(os.path.dirname(__file__), filename)
+def absolute_path(filename: str) -> Path:
+    return Path(__file__).parent / filename
 
 
-def open_file(name, mode="rb"):
-    with open(absolute_path(name), mode) as f:
-        yield f
+def open_file(name: str, mode: str = "rb") -> Iterator[BinaryIO]:
+    with absolute_path(name).open(mode) as fh:
+        yield fh
 
 
-def open_file_gz(name, mode="rb"):
-    with gzip.GzipFile(absolute_path(name), mode) as f:
-        yield f
+def open_file_gz(name: str, mode: str = "rb") -> Iterator[BinaryIO]:
+    with gzip.GzipFile(absolute_path(name), mode) as fh:
+        yield fh
 
 
 @pytest.fixture
-def gzip_sqfs():
+def gzip_sqfs() -> Iterator[BinaryIO]:
     yield from open_file("data/gzip.sqfs")
 
 
 @pytest.fixture
-def gzip_opts_sqfs():
+def gzip_opts_sqfs() -> Iterator[BinaryIO]:
     yield from open_file("data/gzip-opts.sqfs")
 
 
 @pytest.fixture
-def lz4_sqfs():
+def lz4_sqfs() -> Iterator[BinaryIO]:
     yield from open_file("data/lz4.sqfs")
 
 
 @pytest.fixture
-def lzma_sqfs():
+def lzma_sqfs() -> Iterator[BinaryIO]:
     yield from open_file("data/lzma.sqfs")
 
 
 @pytest.fixture
-def lzo_sqfs():
+def lzo_sqfs() -> Iterator[BinaryIO]:
     yield from open_file("data/lzo.sqfs")
 
 
 @pytest.fixture
-def xz_sqfs():
+def xz_sqfs() -> Iterator[BinaryIO]:
     yield from open_file("data/xz.sqfs")
 
 
 @pytest.fixture
-def zstd_sqfs():
+def zstd_sqfs() -> Iterator[BinaryIO]:
     yield from open_file("data/zstd.sqfs")

tests/test_exceptions.py

@@ -1,10 +1,12 @@
+from __future__ import annotations
+
 import pytest
 
 from dissect.squashfs import exceptions
 
 
 @pytest.mark.parametrize(
-    "exc, std",
+    ("exc", "std"),
     [
         (exceptions.FileNotFoundError, FileNotFoundError),
         (exceptions.IsADirectoryError, IsADirectoryError),