Add a simple perl lint script and fix all the errors it found

This adds a script that checks for common whitespace issues
(per our house style) and can (if run with --write) correct some
of them. It adds a run of the script (without --write) to the
tox config, and includes fixes for all the issues the script
discovered in the existing tests and libs.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

lib/anaconda.pm

@@ -467,5 +467,4 @@ sub report_bug_text {
 
     # Quit anaconda
     type_string "4\n";
-    
 }

perllint.py

@@ -0,0 +1,110 @@
+#!/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). It does not currently
+attempt to replace tabs or correct leading whitespace.
+"""
+
+import glob
+import os
+import sys
+
+
+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 = []
+        for (num, line) in enumerate(lines, 1):
+            # tab check
+            if "\t" in line:
+                print(f"Line {num} of file {filename} contains a tab!")
+                failed = True
+
+            # 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
+            spaces = 0
+            for char in line:
+                if char != " ":
+                    break
+                spaces += 1
+            if spaces > 0 and spaces % 4 != 0:
+                print(
+                    f"Line {num} of file {filename} starts with an invalid number of spaces!"
+                )
+                failed = True
+
+            # 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)

tox.ini

@@ -14,6 +14,7 @@ deps =
 commands=
     python ./fifloader.py --clean templates.fif.json templates-updates.fif.json
     python ./check-needles.py
+    python ./perllint.py
     py.test unittests/
     py.test --cov-report term-missing --cov-report xml --cov fifloader unittests/
     diff-cover coverage.xml --fail-under=90 --compare-branch=origin/main