diff --git a/tests/phpunit/tests/functions/wpNonceUrl.php b/tests/phpunit/tests/functions/wpNonceUrl.php
new file mode 100644
index 0000000000000..f98b3a3fe81e5
--- /dev/null
+++ b/tests/phpunit/tests/functions/wpNonceUrl.php
@@ -0,0 +1,145 @@
+<?php
+
+/**
+ * @group functions.php
+ *
+ * @covers ::wp_nonce_url
+ */
+class Tests_Functions_WpNonceUrl extends WP_UnitTestCase {
+	/**
+	 * Tests that wp_nonce_url() appends the nonce name and value to the URL.
+	 *
+	 * @ticket 54870
+	 *
+	 * @dataProvider data_should_append_nonce_name_and_value
+	 *
+	 * @param string     $actionurl URL to add nonce action.
+	 * @param int|string $action    Optional. Nonce action name. Default -1.
+	 * @param string     $name      Optional. Nonce name. Default '_wpnonce'.
+	 */
+	public function test_should_append_nonce_name_and_value( $actionurl, $action = -1, $name = '_wpnonce' ) {
+		$actual        = wp_nonce_url( $actionurl, $action, $name );
+		$url_with_name = "$actionurl?$name=";
+		$nonce         = str_replace( $url_with_name, '', $actual );
+
+		$this->assertStringContainsString(
+			$url_with_name,
+			$actual,
+			'The URL did not contain the action URL and the nonce name'
+		);
+
+		$this->assertNotFalse(
+			wp_verify_nonce( $nonce, $action ),
+			'The nonce is invalid'
+		);
+	}
+
+	/**
+	 * Data provider for test_should_append_nonce_name_and_value().
+	 *
+	 * @return array
+	 */
+	public function data_should_append_nonce_name_and_value() {
+		return array(
+			'http:// and default action/name'             => array(
+				'actionurl' => 'http://example.org/',
+			),
+			'http:// and a custom nonce action'           => array(
+				'actionurl' => 'http://example.org/',
+				'action'    => 'my_action',
+			),
+			'http:// and a custom nonce name'             => array(
+				'actionurl' => 'http://example.org/',
+				'action'    => -1,
+				'name'      => 'my_nonce',
+			),
+			'http:// and a custom nonce action and name'  => array(
+				'actionurl' => 'http://example.org/',
+				'action'    => 'my_action',
+				'name'      => 'my_nonce',
+			),
+			'https:// and default action/name'            => array(
+				'actionurl' => 'https://example.org/',
+			),
+			'https:// and a custom nonce action'          => array(
+				'actionurl' => 'https://example.org/',
+				'action'    => 'my_action',
+			),
+			'https:// and a custom nonce name'            => array(
+				'actionurl' => 'https://example.org/',
+				'action'    => -1,
+				'name'      => 'my_nonce',
+			),
+			'https:// and a custom nonce action and name' => array(
+				'actionurl' => 'https://example.org/',
+				'action'    => 'my_action',
+				'name'      => 'my_nonce',
+			),
+			'/ and default nonce action/name'             => array(
+				'actionurl' => '/',
+			),
+			'/ and a custom nonce action'                 => array(
+				'actionurl' => '/',
+				'action'    => 'my_action',
+			),
+			'/ and a custom nonce name'                   => array(
+				'actionurl' => '/',
+				'action'    => -1,
+				'name'      => 'my_nonce',
+			),
+			'/ and a custom nonce action and name'        => array(
+				'actionurl' => '/',
+				'action'    => 'my_action',
+				'name'      => 'my_nonce',
+			),
+		);
+	}
+
+	/**
+	 * Tests that wp_nonce_url() handles existing query args.
+	 *
+	 * @ticket 54870
+	 *
+	 * @dataProvider data_should_handle_existing_query_args
+	 *
+	 * @param string $actionurl URL to add nonce action.
+	 * @param string $expected  The expected result.
+	 */
+	public function test_should_handle_existing_query_args( $actionurl, $expected ) {
+		$actual = wp_nonce_url( $actionurl );
+
+		$this->assertStringStartsWith(
+			$expected,
+			$actual,
+			'The nonced URL did not start with the expected value.'
+		);
+
+		$this->assertSame(
+			strlen( $expected ) + 10,
+			strlen( $actual ),
+			'The nonced URL was not the expected length.'
+		);
+	}
+
+	/**
+	 * Data provider for test_should_handle_existing_query_args().
+	 *
+	 * @return array
+	 */
+	public function data_should_handle_existing_query_args() {
+		return array(
+			'one query arg'            => array(
+				'actionurl' => 'http://example.org/?hello=world',
+				'expected'  => 'http://example.org/?hello=world&amp;_wpnonce=',
+			),
+			'two query args'           => array(
+				'actionurl' => 'http://example.org/?hello=world&howdy=admin',
+				'expected'  => 'http://example.org/?hello=world&amp;howdy=admin&amp;_wpnonce=',
+			),
+			'two query args and &amp;' => array(
+				'actionurl' => 'http://example.org/?hello=world&amp;howdy=admin',
+				'expected'  => 'http://example.org/?hello=world&amp;howdy=admin&amp;_wpnonce=',
+			),
+		);
+	}
+}