test(policy): add structured signature footer value normalization tests

Signed-off-by: Vitor Mattos <1079143+vitormattos@users.noreply.github.com>

Author: vitormattos

tests/php/Unit/Service/Policy/Provider/Footer/SignatureFooterPolicyValueTest.php

@@ -0,0 +1,57 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2026 LibreCode coop and contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Libresign\Tests\Unit\Service\Policy\Provider\Footer;
+
+use OCA\Libresign\Service\Policy\Provider\Footer\SignatureFooterPolicyValue;
+use PHPUnit\Framework\TestCase;
+
+final class SignatureFooterPolicyValueTest extends TestCase {
+	public function testDefaultsAreStable(): void {
+		$this->assertSame([
+			'enabled' => true,
+			'writeQrcodeOnFooter' => true,
+			'validationSite' => '',
+			'customizeFooterTemplate' => false,
+		], SignatureFooterPolicyValue::defaults());
+	}
+
+	public function testNormalizeLegacyBooleanInput(): void {
+		$this->assertSame([
+			'enabled' => false,
+			'writeQrcodeOnFooter' => true,
+			'validationSite' => '',
+			'customizeFooterTemplate' => false,
+		], SignatureFooterPolicyValue::normalize('0'));
+	}
+
+	public function testNormalizeStructuredJsonInput(): void {
+		$normalized = SignatureFooterPolicyValue::normalize(
+			'{"enabled":true,"writeQrcodeOnFooter":false,"validationSite":"https://validation.example","customizeFooterTemplate":true}'
+		);
+
+		$this->assertSame([
+			'enabled' => true,
+			'writeQrcodeOnFooter' => false,
+			'validationSite' => 'https://validation.example',
+			'customizeFooterTemplate' => true,
+		], $normalized);
+	}
+
+	public function testEncodeReturnsCanonicalPayload(): void {
+		$this->assertSame(
+			'{"enabled":true,"writeQrcodeOnFooter":true,"validationSite":"","customizeFooterTemplate":false}',
+			SignatureFooterPolicyValue::encode([
+				'enabled' => true,
+				'writeQrcodeOnFooter' => true,
+				'validationSite' => '',
+				'customizeFooterTemplate' => false,
+			]),
+		);
+	}
+}