dev/format_check.py

#!/usr/bin/env python3
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may not
# use this file except in compliance with the License. You may obtain a copy of
# the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations under
# the License.

"""Erlang formatter for CouchDB
Warning: this file needs to run from the CouchDB repo root.
USAGE: ERLFMT_PATH=<path_to_erlfmt> python3 dev/format_check.py
"""

import os
import subprocess
import sys

from format_lib import get_source_paths

FILTERED_LINES = [
    "Checking formatting...",
    "[warn] Code style issues found in the above file(s). Forgot to run erlfmt?",
    "",
]

if __name__ == "__main__":
    failed_checks = 0
    for item in get_source_paths():
        run_result = subprocess.run(
            [
                os.environ["ERLFMT_PATH"],
                "-c",
                "--verbose",
                # We have some long lines and erlfmt doesn't forcefully wrap
                # them all. We should decrease this over time
                "--print-width=167",
                item["raw_path"],
            ],
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE,
        )
        if run_result.returncode != 0:
            # erlfmt sometimes returns a non-zero status code with no
            # actual errors. This is a workaround
            stderr_lines = [
                line
                for line in run_result.stderr.decode("utf-8").split("\n")
                if line not in FILTERED_LINES
                and not line.startswith("Formatting ")
                and not line.startswith("[warn] ")
            ]
            if len(stderr_lines) > 0:
                print("\n".join(stderr_lines), file=sys.stderr)
                failed_checks += 1
    sys.exit(failed_checks)