Ruff, some annotations, and some environment tweaking.

avif/__init__.py

@@ -1 +1,6 @@
-from avif._api import AVIFError, Decoder  # noqa: F401
+"""
+Python bindings for libavif.
+"""
+from avif._api import AVIFError, Decoder
+
+__all__ = ["AVIFError", "Decoder"]

avif/_api.py

@@ -9,11 +9,10 @@ class AVIFError(Exception):
     pass
 
 
-def _succeed(avif_result):
+def _succeed(avif_result: int):
     """
     Raise an exception if a ``libavif`` library function failed.
     """
-
     if avif_result != lib.AVIF_RESULT_OK:
         c_string = lib.avifResultToString(avif_result)
         raise AVIFError(ffi.string(c_string).decode("utf-8"))
@@ -23,7 +22,6 @@ def _avifDecoder():
     """
     Create an FFI-managed avifDecoder.
     """
-
     return ffi.gc(lib.avifDecoderCreate(), lib.avifDecoderDestroy)
 
 
@@ -35,12 +33,12 @@ class Decoder:
 
     _decoder = attr.ib(factory=_avifDecoder)
 
-    def parse_path(self, path):
+    def parse_path(self, path: str):
         _succeed(lib.avifDecoderSetIOFile(self._decoder, os.fsencode(path)))
         _succeed(lib.avifDecoderParse(self._decoder))
         return self._decoder.image
 
-    def parse_data(self, data):
+    def parse_data(self, data: bytes):
         _succeed(lib.avifDecoderSetIOMemory(self._decoder, data, len(data)))
         _succeed(lib.avifDecoderParse(self._decoder))
         return self._decoder.image
@@ -53,7 +51,7 @@ def next_images(self):
             _succeed(res)
             yield self._decoder.image
 
-    def nth_image(self, n):
+    def nth_image(self, n: int):
         _succeed(lib.avifDecoderNthImage(self._decoder, n))
 
         return self._decoder.image

avif/pillow/__init__.py

@@ -1,5 +1,8 @@
 """
-Pillow plugin for decoding animated and static avif files. (only 8bit)
+Pillow plugin for decoding animated and static avif files.
+
+Only 8-bit files are currently supported.
+
 Based on:
 https://github.com/python-pillow/Pillow/blob/master/src/PIL/WebPImagePlugin.py
 """
@@ -12,13 +15,17 @@
 from avif import Decoder
 
 
-def _accept(data):
+def _accept(data: bytes):
     possible_ftyp = (b"avif", b"avis", b"mif1")
 
     return data[4:8] == b"ftyp" and data[8:12] in possible_ftyp
 
 
 class AvifImageFile(ImageFile.ImageFile):
+    """
+    A Pillow ImageFile for AVIF.
+    """
+
     format = "AVIF"
     format_description = "Image container for AV1 video frames"
 
@@ -43,7 +50,10 @@ def _open(self):
         self.rawmode = self.mode
         self.tile = []
 
-    def seek(self, n):
+    def seek(self, n: int) -> None:
+        """
+        Seek!
+        """
         self._seek_to_frame = n
 
     def _get_frame(self):
@@ -62,7 +72,10 @@ def _get_frame(self):
 
         return data
 
-    def load(self):
+    def load(self) -> Image.PixelAccess:
+        """
+        Load!
+        """
         if self._current_frame != self._seek_to_frame:
             self._current_frame = self._seek_to_frame
 

avif/tests/test_avif.py

@@ -1,8 +1,5 @@
 def test_it_imports():
-    import _avif
-
-    _avif
-
     from avif import Decoder
+    import _avif  # noqa: F401
 
     Decoder()

examples/avif_example_decode_file.py

@@ -8,7 +8,7 @@
 from avif import Decoder
 
 
-def main():
+def main() -> None:
     filename = sys.argv[1]
 
     rgb = ffi.new("avifRGBImage*")

examples/avif_example_pillow_decode_file.py

@@ -12,7 +12,7 @@
 import avif.pillow  # noqa: F401
 
 
-def main():
+def main() -> None:
     filename = sys.argv[1]
 
     image = Image.open(filename)

noxfile.py

@@ -1,4 +1,6 @@
 from pathlib import Path
+from tempfile import TemporaryDirectory
+import os
 
 import nox
 
@@ -21,42 +23,47 @@ def _session(fn):
 
 @session(python=["3.8", "3.9", "3.10", "3.11", "pypy3"])
 def tests(session):
-    session.install(str(ROOT), "pytest")
-    session.run("pytest")
+    session.install(ROOT, "pytest")
 
+    if session.posargs and session.posargs[0] == "coverage":
+        if len(session.posargs) > 1 and session.posargs[1] == "github":
+            github = os.environ["GITHUB_STEP_SUMMARY"]
+        else:
+            github = None
 
-@session(tags=["build"])
-def build(session):
-    session.install("build")
-    tmpdir = session.create_tmp()
-    session.run("python", "-m", "build", str(ROOT), "--outdir", tmpdir)
+        session.install("coverage[toml]")
+        session.run("coverage", "run", "-m", "pytest", AVIF)
+        if github is None:
+            session.run("coverage", "report")
+        else:
+            with open(github, "a") as summary:
+                summary.write("### Coverage\n\n")
+                summary.flush()  # without a flush, output seems out of order.
+                session.run(
+                    "coverage",
+                    "report",
+                    "--format=markdown",
+                    stdout=summary,
+                )
+    else:
+        session.run("pytest", *session.posargs, AVIF)
 
 
-@session(tags=["style"])
-def readme(session):
+@session()
+def audit(session):
+    session.install("pip-audit", ROOT)
+    session.run("python", "-m", "pip_audit")
+
+
+@session(tags=["build"])
+def build(session):
     session.install("build", "twine")
-    tmpdir = session.create_tmp()
-    session.run("python", "-m", "build", str(ROOT), "--outdir", tmpdir)
-    session.run("python", "-m", "twine", "check", tmpdir + "/*")
+    with TemporaryDirectory() as tmpdir:
+        session.run("python", "-m", "build", ROOT, "--outdir", tmpdir)
+        session.run("twine", "check", "--strict", tmpdir + "/*")
 
 
 @session(tags=["style"])
 def style(session):
-    session.install(
-        "flake8",
-        "flake8-broken-line",
-        "flake8-bugbear",
-        "flake8-commas",
-        "flake8-quotes",
-        "flake8-tidy-imports",
-    )
-    session.run(
-        "python",
-        "-m",
-        "flake8",
-        "--config",
-        str(ROOT / ".flake8"),
-        str(EXAMPLES),
-        str(AVIF),
-        __file__,
-    )
+    session.install("ruff")
+    session.run("ruff", "check", ROOT)

pyproject.toml

@@ -7,10 +7,77 @@ requires = [
 ]
 build-backend = "setuptools.build_meta"
 
+[tool.coverage.html]
+show_contexts = true
+skip_covered = false
+
+[tool.coverage.run]
+branch = true
+source = ["referencing"]
+dynamic_context = "test_function"
+
+[tool.coverage.report]
+exclude_also = [
+  "if TYPE_CHECKING:",
+  "\\s*\\.\\.\\.\\s*",
+]
+show_missing = true
+skip_covered = true
+
+[tool.doc8]
+ignore = [
+    "D001",  # one sentence per line, so max length doesn't make sense
+]
+
 [tool.isort]
+combine_as_imports = true
 from_first = true
 include_trailing_comma = true
 known_first_party = "_avif"
 multi_line_output = 3
 
 [tool.setuptools_scm]
+
+[tool.ruff]
+line-length = 79
+target-version = "py38"
+select = ["ANN", "B", "D", "E", "F", "Q", "UP", "W"]
+ignore = [
+  # Wat, type annotations for self and cls, why is this a thing?
+  "ANN101",
+  "ANN102",
+  # Private annotations are fine to leave out.
+  "ANN202",
+  # I don't know how to more properly annotate "pass along all arguments".
+  "ANN401",
+  # raise SomeException(...) is fine.
+  "B904",
+  # It's fine to not have docstrings for magic methods.
+  "D105",
+  # This rule makes diffs uglier when expanding docstrings (and it's uglier)
+  "D200",
+  # No blank lines before docstrings.
+  "D203",
+  # Start docstrings on the second line.
+  "D212",
+  # This rule misses sassy docstrings ending with ! or ?.
+  "D400",
+  # Section headers should end with a colon not a newline
+  "D406",
+  # Underlines aren't needed
+  "D407",
+  # Plz spaces after section headers
+  "D412",
+  # We support 3.8 + 3.9
+  "UP007",
+]
+
+[tool.ruff.flake8-quotes]
+docstring-quotes = "double"
+
+[tool.ruff.per-file-ignores]
+"docs/*" = ["ANN", "D"]
+"examples*" = ["D103"]
+"avif/tests/*" = ["ANN", "D"]
+"noxfile.py" = ["ANN", "D"]
+"setup.py" = ["ANN", "D"]