Ensure all string functions are multibyte-safe where possible

.gitignore

@@ -1,3 +1,4 @@
 /composer.lock
 /vendor
 /.idea
+/.php_cs.cache

.php_cs

@@ -0,0 +1,12 @@
+<?php
+
+$finder = PhpCsFixer\Finder::create()->in(__DIR__);
+
+return PhpCsFixer\Config::create()
+    ->setRules(
+        [
+            'mb_str_functions' => true,
+        ]
+    )
+    ->setRiskyAllowed(true)
+    ->setFinder($finder);

.travis.yml

@@ -6,6 +6,7 @@ before_script:
   - composer self-update
   - composer install
 script:
+  - php vendor/bin/php-cs-fixer fix --verbose --dry-run --using-cache=no
   - php vendor/bin/phpunit --coverage-clover=coverage.clover
   - php vendor/bin/phpstan analyse --no-interaction
   - php vendor/bin/psalm

composer.json

@@ -22,6 +22,7 @@
         "psr/http-server-middleware": "^1.0"
     },
     "require-dev": {
+        "friendsofphp/php-cs-fixer": "^2.16",
         "laminas/laminas-diactoros": "~2.2",
         "phpstan/phpstan": "^0.12.14",
         "phpunit/phpunit": "~7.0",
@@ -46,9 +47,13 @@
     },
     "scripts": {
         "test": [
-            "phpunit",
+            "php-cs-fixer fix --verbose --dry-run",
             "phpstan analyse",
-            "psalm"
+            "psalm",
+            "phpunit"
+        ],
+        "fix": [
+            "php-cs-fixer fix --verbose"
         ]
     }
 }