From 5d883a10d23abf9583ae3806bc705a37e2c4522c Mon Sep 17 00:00:00 2001
From: Paul Bearne <pbearne@git.wordpress.org>
Date: Thu, 7 May 2026 11:56:00 -0400
Subject: [PATCH] Add unit tests for update_home_siteurl() in
 wp-admin/includes/misc.php

---
 .../admin/includes/misc/updateHomeSiteurl.php | 112 ++++++++++++++++++
 1 file changed, 112 insertions(+)
 create mode 100644 tests/phpunit/tests/admin/includes/misc/updateHomeSiteurl.php

diff --git a/tests/phpunit/tests/admin/includes/misc/updateHomeSiteurl.php b/tests/phpunit/tests/admin/includes/misc/updateHomeSiteurl.php
new file mode 100644
index 0000000000000..a6d3d9dae8318
--- /dev/null
+++ b/tests/phpunit/tests/admin/includes/misc/updateHomeSiteurl.php
@@ -0,0 +1,112 @@
+<?php
+/**
+ * Test update_home_siteurl().
+ *
+ * @group admin
+ * @group misc
+ *
+ * @covers ::update_home_siteurl
+ */
+class Tests_Admin_Includes_Misc_UpdateHomeSiteurl extends WP_UnitTestCase {
+
+	/**
+	 * Tests update_home_siteurl() when wp_installing() is true.
+	 *
+	 * @ticket 65194
+	 */
+	public function test_update_home_siteurl_should_not_flush_when_installing() {
+		wp_installing( true );
+
+		// We use a filter to detect if flush_rewrite_rules is called.
+		// Since flush_rewrite_rules calls delete_option( 'rewrite_rules' ) and update_option( 'rewrite_rules' ),
+		// we can monitor those, or just check if rewrite_rules are touched.
+		// However, flush_rewrite_rules() is a complex function.
+		// A simpler way is to check if it returns early by mocking/monitoring.
+
+		$option_updated = false;
+		add_filter( 'pre_update_option_rewrite_rules', function( $value ) use ( &$option_updated ) {
+			$option_updated = true;
+			return $value;
+		} );
+
+		update_home_siteurl( 'http://old.example.com', 'http://new.example.com' );
+
+		$this->assertFalse( $option_updated, 'Rewrite rules should not be flushed when installing.' );
+
+		wp_installing( false ); // Reset.
+	}
+
+	/**
+	 * Tests update_home_siteurl() in single site mode.
+	 *
+	 * @ticket 65194
+	 */
+	public function test_update_home_siteurl_should_flush_rules_on_single_site() {
+		if ( is_multisite() ) {
+			$this->markTestSkipped( 'This test is for single site only.' );
+		}
+
+		$option_updated = false;
+		add_filter( 'pre_update_option_rewrite_rules', function( $value ) use ( &$option_updated ) {
+			$option_updated = true;
+			return $value;
+		} );
+
+		// flush_rewrite_rules() might not update the option if it's already empty or similar.
+		// Let's ensure there are rules to flush.
+		update_option( 'rewrite_rules', array( 'foo' => 'bar' ) );
+		$option_updated = false;
+
+		update_home_siteurl( 'http://old.example.com', 'http://new.example.com' );
+
+		$this->assertTrue( $option_updated, 'Rewrite rules should be flushed on single site.' );
+	}
+
+	/**
+	 * Tests update_home_siteurl() in multisite mode when NOT switched.
+	 *
+	 * @group multisite
+	 * @ticket 65194
+	 */
+	public function test_update_home_siteurl_multisite_not_switched() {
+		if ( ! is_multisite() ) {
+			$this->markTestSkipped( 'This test is for multisite only.' );
+		}
+
+		$option_updated = false;
+		add_filter( 'pre_update_option_rewrite_rules', function( $value ) use ( &$option_updated ) {
+			$option_updated = true;
+			return $value;
+		} );
+
+		update_option( 'rewrite_rules', array( 'foo' => 'bar' ) );
+		$option_updated = false;
+
+		update_home_siteurl( 'http://old.example.com', 'http://new.example.com' );
+
+		$this->assertTrue( $option_updated, 'Rewrite rules should be flushed in multisite when not switched.' );
+	}
+
+	/**
+	 * Tests update_home_siteurl() in multisite mode when switched.
+	 *
+	 * @group multisite
+	 * @ticket 65194
+	 */
+	public function test_update_home_siteurl_multisite_switched() {
+		if ( ! is_multisite() ) {
+			$this->markTestSkipped( 'This test is for multisite only.' );
+		}
+
+		$blog_id = $this->factory->blog->create();
+		switch_to_blog( $blog_id );
+
+		update_option( 'rewrite_rules', array( 'foo' => 'bar' ) );
+
+		update_home_siteurl( 'http://old.example.com', 'http://new.example.com' );
+
+		$this->assertFalse( get_option( 'rewrite_rules' ), 'Rewrite rules option should be deleted when switched in multisite.' );
+
+		restore_current_blog();
+	}
+}