os-autoinst-distri-fedora/perllint.py

#!/usr/bin/python3

# Copyright Red Hat
#
# This file is part of os-autoinst-distri-fedora.
#
# os-autoinst-distri-fedora is free software; you can redistribute it
# and/or modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation, either version 2 of
# the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# Author: Adam Williamson <awilliam@redhat.com>

"""This is a simple linter for perl files in the repository. It fails
if any line contains a tab, ends with whitespace characters (which
includes lines containing *only* whitespace characters), or starts
with a number of spaces that is not divisible by four. If run with
--write, it will strip trailing whitespace (including turning lines
that contain only whitespace into blank lines) and correct indentation
(including removing tabs in indentation). It does not do anything
with tabs found outside of leading indentation.
"""

import glob
import os
import re
import sys

HEREDOCRE = re.compile(r"<<['\"]?(\w*)['\"]?;\s*$")

def run(write):
    """
    Main run function.
    """
    exitcode = 0
    scriptloc = os.path.dirname(os.path.realpath(__file__))
    filenames = glob.glob(f"{scriptloc}/**/*.pm", recursive=True)
    for filename in filenames:
        if check_file(filename, write):
            exitcode = 1
    if exitcode == 0:
        print("No errors found!")
    sys.exit(exitcode)


def check_file(filename, write):
    """
    Do the checks. Returns false if there is no failure, true if there
    is a failure.
    """
    failed = False
    with open(filename, "r", encoding="UTF-8") as readfh:
        lines = readfh.readlines()
        newlines = []
        indent = 0
        # indicator whether we're in a heredoc block
        heredoc = None
        for (num, line) in enumerate(lines, 1):
            # if we're in a heredoc, skip all checks, and see if we
            # ended it
            if heredoc:
                if line.strip(" \t").rstrip(" \t\n") == heredoc:
                    heredoc = None
                # write the line back to newlines
                if write:
                    newlines.append(line)
                continue
            # trailing whitespace check and replace
            newline = line.rstrip("\n").rstrip(" \t") + "\n"
            if newline != line:
                print(f"Line {num} of file {filename} ends with a space or tab!")
                failed = True
                if write:
                    # if we're writing changes, feed the *changed* line
                    # to the next checks
                    line = newline

            # correct number of starting spaces check
            # skip non-indented comment lines
            if line.startswith("#  "):
                # write the line back to newlines
                if write:
                    newlines.append(line)
                continue
            # first update indent if line closes a block
            if line.strip(" \t").startswith("}") or line.strip(" \t").startswith(")"):
                indent -= 4
            spaces = 0
            for char in line:
                if char != " ":
                    break
                spaces += 1
            if spaces != indent and line != "\n":
                print(
                    f"Line {num} of file {filename} starts with an invalid number of spaces! Expected {indent} got {spaces}"
                )
                failed = True
                if write:
                    line = line.lstrip()
                    if line.startswith("\t"):
                        print(f"Line {num} of file {filename} has a tab in leading whitespace!")
                        line = line.strip(" \t")
                    line = " " * indent + line
            # now update indent if line opens a block (and isn't a comment)
            if not line.strip(" \t").startswith("#"):
                if line.rstrip(" \t\n").endswith("{") or line.rstrip(" \t\n").endswith("("):
                    indent += 4

            # tab check
            if "\t" in line:
                print(f"Line {num} of file {filename} contains a tab!")
                failed = True

            # did the line start a heredoc?
            herematch = HEREDOCRE.search(line)
            if herematch:
                heredoc = herematch.group(1)

            # write the line back to newlines
            if write:
                newlines.append(line)

    if write and newlines != lines:
        with open(filename, "w", encoding="UTF-8") as writefh:
            writefh.writelines(newlines)

    return failed


# Parse args and call run().
if len(sys.argv) > 2:
    sys.exit("Too many arguments!")

if len(sys.argv) > 1:
    if sys.argv[1] == "--write":
        run(write=True)
    else:
        sys.exit("Invalid argument! Only valid argument is --write")

# no args
run(write=False)