Derive mode from DSN function

- Add headers in all files
- Minor field name changes

tests/unit/ModeTest.php

@@ -0,0 +1,39 @@
+<?php
+/**
+ * @author Daniel J. Summers <daniel@bitbadger.solutions>
+ * @license MIT
+ */
+
+declare(strict_types=1);
+
+namespace Test\Unit;
+
+use BitBadger\PDODocument\{DocumentException, Mode};
+use PHPUnit\Framework\Attributes\TestDox;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Unit tests for the Mode enumeration
+ */
+#[TestDox('Mode (Unit tests)')]
+class ModeTest extends TestCase
+{
+    #[TestDox('Derive from DSN succeeds for PostgreSQL')]
+    public function testDeriveFromDSNSucceedsForPostgreSQL(): void
+    {
+        $this->assertEquals(Mode::PgSQL, Mode::deriveFromDSN('pgsql:Host=localhost'), 'PostgreSQL mode incorrect');
+    }
+
+    #[TestDox('Derive from DSN succeeds for SQLite')]
+    public function testDeriveFromDSNSucceedsForSQLite(): void
+    {
+        $this->assertEquals(Mode::SQLite, Mode::deriveFromDSN('sqlite:data.db'), 'SQLite mode incorrect');
+    }
+
+    #[TestDox('Derive from DSN fails for MySQL')]
+    public function testDeriveFromDSNFailsForMySQL(): void
+    {
+        $this->expectException(DocumentException::class);
+        Mode::deriveFromDSN('mysql:Host=localhost');
+    }
+}