diff --git a/tests/phpunit/tests/functions/getNumQueries.php b/tests/phpunit/tests/functions/getNumQueries.php
new file mode 100644
index 0000000000000..c23a525141eae
--- /dev/null
+++ b/tests/phpunit/tests/functions/getNumQueries.php
@@ -0,0 +1,28 @@
+<?php
+/**
+ * Tests for get_num_queries().
+ *
+ * @group functions
+ * @group wpdb
+ *
+ * @covers ::get_num_queries
+ */
+class Tests_Functions_getNumQueries extends WP_UnitTestCase {
+	/**
+	 * Tests that making a database query increases the number of queries.
+	 *
+	 * @ticket 54490
+	 */
+	public function test_get_num_queries() {
+		global $wpdb;
+
+		$current_count = get_num_queries();
+		$this->assertIsInt( $current_count, 'get_num_queries() did not return an integer.' );
+
+		// Do a single database query.
+		$wpdb->query( 'SELECT NOW();' );
+
+		// Check the count increased by one.
+		$this->assertSame( $current_count + 1, get_num_queries(), 'The number of queries did not increase by one.' );
+	}
+}
diff --git a/tests/phpunit/tests/functions/wpGetNocacheHeaders.php b/tests/phpunit/tests/functions/wpGetNocacheHeaders.php
new file mode 100644
index 0000000000000..0f2b5eb4fa202
--- /dev/null
+++ b/tests/phpunit/tests/functions/wpGetNocacheHeaders.php
@@ -0,0 +1,82 @@
+<?php
+/**
+ * Tests for wp_get_nocache_headers().
+ *
+ * @group functions
+ *
+ * @covers ::wp_get_nocache_headers
+ */
+class Tests_Functions_wpGetNocacheHeaders extends WP_UnitTestCase {
+	/**
+	 * User ID.
+	 *
+	 * @var int
+	 */
+	public static $user_id;
+
+	/**
+	 * Creates a user account for tests.
+	 *
+	 * @param WP_UnitTest_Factory $factory
+	 */
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$user_id = $factory->user->create();
+	}
+
+	/**
+	 * Tests nocache headers are as expected for a logged out user.
+	 *
+	 * @ticket 54490
+	 */
+	public function test_wp_get_nocache_headers_for_logged_out_user() {
+		$this->assertSameSetsWithIndex(
+			array(
+				'Expires'       => 'Wed, 11 Jan 1984 05:00:00 GMT',
+				'Cache-Control' => 'no-cache, must-revalidate, max-age=0, no-store, private',
+				'Last-Modified' => false,
+			),
+			wp_get_nocache_headers()
+		);
+	}
+
+	/**
+	 * Tests nocache headers are as expected for a logged in user.
+	 *
+	 * @ticket 21938
+	 * @ticket 54490
+	 */
+	public function test_wp_get_nocache_headers_for_logged_in_user() {
+		wp_set_current_user( self::$user_id );
+
+		$this->assertSameSetsWithIndex(
+			array(
+				'Expires'       => 'Wed, 11 Jan 1984 05:00:00 GMT',
+				'Cache-Control' => 'no-cache, must-revalidate, max-age=0, no-store, private',
+				'Last-Modified' => false,
+			),
+			wp_get_nocache_headers()
+		);
+	}
+
+	/**
+	 * Tests the `nocache_headers` filter fires and filters the headers.
+	 *
+	 * @ticket 54490
+	 */
+	public function test_filter_nocache_headers() {
+		add_filter(
+			'nocache_headers',
+			static function () {
+				return array( 'filter_name' => 'nocache_headers' );
+			}
+		);
+
+		$this->assertSameSetsWithIndex(
+			array(
+				'filter_name'   => 'nocache_headers',
+				'Last-Modified' => false,
+			),
+			wp_get_nocache_headers()
+		);
+	}
+}