Issue #3336828: File dictionary.txt is not sorted

core/tests/Drupal/Tests/CSpell/SortTest.php

+<?php
+
+namespace Drupal\Tests\CSpell;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Tests that the dictionary.txt file is properly sorted.
+ *
+ * @group cspell
+ */
+class SortTest extends TestCase {
+
+  /**
+   * The path to the dictionary file.
+   */
+  private string $filePath;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    $this->filePath = dirname(__DIR__, 5) . '/core/misc/cspell/dictionary.txt';
+  }
+
+  /**
+   * Tests that the file exists.
+   */
+  public function testFileExists() {
+    $this->assertFileExists($this->filePath);
+  }
+
+  /**
+   * Tests that the file is properly sorted.
+   */
+  public function testSorted() {
+    $content = file_get_contents($this->filePath);
+    $this->assertIsString($content);
+    $current_dictionary = explode("\n", rtrim($content));
+    $this->assertIsArray($current_dictionary);
+    $sorted_dictionary = $current_dictionary;
+    sort($current_dictionary);
+    $this->assertSame($current_dictionary, $sorted_dictionary);
+  }
+
+}