Fix: Simplify

src/Extension.php

@@ -18,15 +18,15 @@
 use PHPUnit\Util;
 
 try {
-    $phpUnitVersion = Version\Version::fromString(Runner\Version::id());
+    $phpUnitVersionSeries = Version\Series::fromString(Runner\Version::series());
 } catch (\InvalidArgumentException $exception) {
     throw new \RuntimeException(\sprintf(
-        'Unable to determine PHPUnit version from version identifier "%s".',
-        Runner\Version::id(),
+        'Unable to determine PHPUnit version from version series "%s".',
+        Runner\Version::series(),
     ));
 }
 
-if ($phpUnitVersion->major()->equals(Version\Major::fromInt(9))) {
+if ($phpUnitVersionSeries->major()->equals(Version\Major::fromInt(9))) {
     /**
      * @internal
      */
@@ -166,7 +166,7 @@ private function resolveMaximumDuration(string $test): Duration
             return $this->maximumDuration;
         }
     }
-} elseif ($phpUnitVersion->major()->equals(Version\Major::fromInt(10))) {
+} elseif ($phpUnitVersionSeries->major()->equals(Version\Major::fromInt(10))) {
     /**
      * @internal
      */
@@ -217,7 +217,7 @@ public function bootstrap(
     }
 } else {
     throw new \RuntimeException(\sprintf(
-        'Unable to select extension for PHPUnit version with version identifier "%s".',
-        Runner\Version::id(),
+        'Unable to select extension for PHPUnit version with version series "%s".',
+        Runner\Version::series(),
     ));
 }

src/Version/Series.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright (c) 2021-2023 Andreas Möller
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE.md file that was distributed with this source code.
+ *
+ * @see https://github.com/ergebnis/phpunit-slow-test-detector
+ */
+
+namespace Ergebnis\PHPUnit\SlowTestDetector\Version;
+
+/**
+ * @internal
+ */
+final class Series
+{
+    private Major $major;
+
+    private function __construct(Major $major)
+    {
+        $this->major = $major;
+    }
+
+    public static function create(Major $major): self
+    {
+        return new self($major);
+    }
+
+    /**
+     * @throws \InvalidArgumentException
+     */
+    public static function fromString(string $value): self
+    {
+        if (0 === \preg_match('/^(?P<major>(0|[1-9]\d*))\.(?P<minor>(0|[1-9]\d*))?$/', $value, $matches)) {
+            throw new \InvalidArgumentException(\sprintf(
+                'Value "%s" does not appear to be a valid value for a semantic version.',
+                $value,
+            ));
+        }
+
+        $major = Major::fromInt((int) $matches['major']);
+
+        return self::create($major);
+    }
+
+    public function major(): Major
+    {
+        return $this->major;
+    }
+}