Add GitHub Actions workflow for code style check

.editorconfig

@@ -0,0 +1,9 @@
+root = true
+
+[*]
+end_of_line = lf
+insert_final_newline = true
+
+[*.{pl,pm}]
+indent_style = space
+indent_size = 2

.github/workflows/lint.yml

@@ -0,0 +1,40 @@
+name: Check code
+
+on:
+  pull_request:
+    paths:
+      - '**/*.pl'
+      - '**/*.pm'
+
+jobs:
+  perl-lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Perl
+        uses: shogo82148/actions-setup-perl@v1
+        with:
+          perl-version: '5.28'
+
+      - name: Install perltidy
+        run: cpanm Perl::Tidy
+
+      - name: Install reviewdog
+        run: wget -O - -q https://raw.githubusercontent.com/reviewdog/reviewdog/master/install.sh | sh -s -- -b /usr/local/bin/ 2>&1
+
+      - name: Run perltidy
+        env:
+          REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          result=0
+          for file in $(git ls-files '*.pl' '*.pm'); do
+            check="$(perltidy -st "$file" | git diff --no-index -- "$file" - | reviewdog -f=diff -name="perltidy" -reporter=local -filter-mode=nofilter)"
+            if [ -n "$check" ]; then
+              echo -e "\033[1;31mError:\033[0m [perltidy] $file:"
+              echo "$check"
+              result=1
+            fi
+          done
+          exit $result

.perltidyrc

@@ -1,5 +1,8 @@
+-b
+-bext=/
 -i=2
 --cuddled-blocks
+--cuddled-paren-brace
 --cuddled-break-option=2
 -nsbl
 --nospace-for-semicolon
@@ -10,6 +13,8 @@
 --square-bracket-tightness=2
 --block-brace-tightness=1
 -novalign
+--valign-side-comments
+--valign-block-comments
 --opening-token-right
 --add-newlines
 --delete-old-newlines
@@ -22,3 +27,11 @@
 --comma-arrow-breakpoints=0
 --keep-old-blank-lines=1
 --keyword-group-blanks
+--extended-continuation-indentation
+--want-trailing-commas=m
+--add-trailing-commas
+--delete-trailing-commas
+--delete-weld-interfering-commas
+--one-line-block-nesting=0
+--output-line-ending=unix
+--add-terminal-newline

perltidy.sh

@@ -0,0 +1,8 @@
+#!/bin/sh
+
+set -e
+
+for file in $(find . -name '*.pl' -o -name '*.pm' | sort); do
+  echo "$file"
+  perltidy "$file"
+done