Ruff has unstable results with target-version (normally hidden by caching) #10267
Description
I am switching from shed to ruff at $WORK and found what looks like a bug in Ruff's formatter (unstable output);
normally this appears to be hidden by caching, implying a second bug in the caching logic.
Here's a minimized repro with target-version and a particular code pattern
(further minimization ideas I tried broke the repro but some likely exist):
Python 3.11.6 | packaged by conda-forge | (main, Oct 3 2023, 10:37:07) [Clang 15.0.7 ]
ruff 0.3.1
N.B. also tested on {python3.11,python3.12} x {ruff==0.3.0, ruff==0.3.1}
Starting hash of file:
57be245f1161c2069df7c842b935038e30c0a17aa31c924218aa925566203636 wat.py
Starting file contents:
with (
open(
"/etc/hosts" # This is an incredibly long comment that has been replaced for sanitization
)
):
pass
When reading from the cache (default behavior), stable after first run:
1 file reformatted
1acf49d050ef0ac27cb93c028af71a4d8d918a91992dbb497c6da52393d91f98 wat.py
with open(
"/etc/hosts" # This is an incredibly long comment that has been replaced for sanitization
):
pass
1 file left unchanged
1acf49d050ef0ac27cb93c028af71a4d8d918a91992dbb497c6da52393d91f98 wat.py
1 file left unchanged
1acf49d050ef0ac27cb93c028af71a4d8d918a91992dbb497c6da52393d91f98 wat.py
If you disable reading from the cache, output flip flops on each run:
1 file reformatted
57be245f1161c2069df7c842b935038e30c0a17aa31c924218aa925566203636 wat.py
1 file reformatted
1acf49d050ef0ac27cb93c028af71a4d8d918a91992dbb497c6da52393d91f98 wat.py
1 file reformatted
57be245f1161c2069df7c842b935038e30c0a17aa31c924218aa925566203636 wat.py
N.B. I have no ruff config settings, and didn't see related issues/PRs but let me know if I missed one!
Script that produced this output
#!/usr/bin/env bash
# no errexit
set -o nounset
set -o pipefail
tmp_dir="$(mktemp -d)"
cleanup() {
rm -rf "${tmp_dir}"
}
trap cleanup EXIT INT QUIT TERM
cd "${tmp_dir}"
# N.B. does not repro if comment is removed and "/etc/hosts" made very long instead
cat >./wat.py <<EOF
with (
open(
"/etc/hosts" # This is an incredibly long comment that has been replaced for sanitization
)
):
pass
EOF
python -m venv ./venv
./venv/bin/pip install --quiet ruff==0.3.1
./venv/bin/python --version --version
./venv/bin/ruff --version
echo 'N.B. also tested on {python3.11,python3.12} x {ruff==0.3.0, ruff==0.3.1}'
echo -e "\nStarting hash of file:"
sha256sum wat.py
echo "Starting file contents:"
cat wat.py
echo -e "\nWhen reading from the cache (default behavior), stable after first run:"
./venv/bin/ruff format --isolated --target-version py310 wat.py
sha256sum wat.py
cat wat.py
./venv/bin/ruff format --isolated --target-version py310 wat.py
sha256sum wat.py
./venv/bin/ruff format --isolated --target-version py310 wat.py
sha256sum wat.py
echo -e "\nIf you disable reading from the cache, output flip flops on each run:"
./venv/bin/ruff format --isolated --target-version py310 --no-cache wat.py
sha256sum wat.py
./venv/bin/ruff format --isolated --target-version py310 --no-cache wat.py
sha256sum wat.py
./venv/bin/ruff format --isolated --target-version py310 --no-cache wat.py
sha256sum wat.py