Meta: Add flake8 to lint python files

Author: https://github.com/ADKaster
Commit: https://github.com/SerenityOS/serenity/commit/b5078530d57
Pull-request: https://github.com/SerenityOS/serenity/pull/4862
Reviewed-by: https://github.com/BenWiederhake
Reviewed-by: https://github.com/alimpfard
Reviewed-by: https://github.com/linusg ✅

Meta/lint-ci.sh

@@ -21,7 +21,8 @@ for cmd in \
         Meta/lint-executable-resources.sh \
         Meta/lint-ipc-ids.sh \
         Meta/lint-shell-scripts.sh \
-        Meta/lint-prettier.sh; do
+        Meta/lint-prettier.sh \
+        Meta/lint-python.sh; do
     echo "Running ${cmd}... "
     if "${cmd}" "$@"; then
         echo -e "[${GREEN}OK${NC}]: ${cmd}"

Meta/lint-python.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+
+set -e
+
+script_path=$(cd -P -- "$(dirname -- "$0")" && pwd -P)
+cd "${script_path}/.." || exit 1
+
+if ! command -v flake8 >/dev/null 2>&1 ; then
+    echo "flake8 is not available. Either skip this script, or install flake8."
+    exit 1
+fi
+
+if [ "$#" -eq "0" ]; then
+    mapfile -t files < <(
+        git ls-files '*.py'
+    )
+else
+    files=()
+    for file in "$@"; do
+        if [[ "${file}" == *".py" ]]; then
+            files+=("${file}")
+        fi
+    done
+fi
+
+if (( ${#files[@]} )); then
+    flake8 "${files[@]}" --max-line-length=120
+else
+    echo "No py files to check."
+fi