Add tests.

composer.json

@@ -34,7 +34,7 @@
         }
     },
     "require-dev": {
-        "phpunit/phpunit": "^11.5",
+        "phpunit/phpunit": "^9.6.22",
         "rector/rector": "^2.0",
         "phpstan/phpstan": "^2.1"
     },

phpunit.xml.dist

@@ -0,0 +1,37 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!-- https://phpunit.readthedocs.io/en/latest/configuration.html -->
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
+         backupGlobals="false"
+         colors="true"
+         bootstrap="tests/bootstrap.php"
+>
+    <php>
+        <ini name="display_errors" value="1" />
+        <ini name="error_reporting" value="-1" />
+        <server name="APP_ENV" value="test" force="true" />
+        <server name="SHELL_VERBOSITY" value="-1" />
+        <server name="SYMFONY_PHPUNIT_REMOVE" value="" />
+        <server name="SYMFONY_PHPUNIT_VERSION" value="9.5" />
+    </php>
+
+    <testsuites>
+        <testsuite name="Symfony Test Files">
+            <directory>tests</directory>
+            <exclude>src/Field/Configurator</exclude>
+            <exclude>src/Subscriber</exclude>
+        </testsuite>
+    </testsuites>
+
+    <coverage processUncoveredFiles="true">
+        <include>
+            <directory suffix=".php">src</directory>
+        </include>
+        <exclude>
+            <directory suffix=".php">src/Field/Configurator</directory>
+            <directory suffix=".php">src/Subscriber</directory>
+            <file>src/FileUploadFieldBundle.php</file>
+        </exclude>
+    </coverage>
+</phpunit>

tests/bootstrap.php

@@ -0,0 +1,11 @@
+<?php
+
+use Symfony\Component\Dotenv\Dotenv;
+
+require dirname(__DIR__).'/vendor/autoload.php';
+
+if (file_exists(dirname(__DIR__).'/config/bootstrap.php')) {
+    require dirname(__DIR__).'/config/bootstrap.php';
+} elseif (method_exists(Dotenv::class, 'bootEnv')) {
+    (new Dotenv())->bootEnv(dirname(__DIR__).'/.env');
+}