Filter which providers should be available to users

tests/bootstrap.php

@@ -23,6 +23,7 @@
  * Manually load the plugin being tested.
  */
 function _manually_load_plugin() {
+	require dirname( __DIR__, 2 ) . '/two-factor/two-factor.php';
 	require dirname( __DIR__ ) . '/wporg-two-factor.php';
 }
 tests_add_filter( 'muplugins_loaded', '_manually_load_plugin' );

tests/test-wporg-two-factor.php

@@ -1,8 +1,19 @@
 <?php
 
-use function WordPressdotorg\Two_Factor\{};
+//use function WordPressdotorg\Two_Factor\{};
 
 defined( 'WPINC' ) || die();
 
 class Test_WPorg_Two_Factor extends WP_UnitTestCase {
+	public function test_two_factor_providers() {
+		$actual = Two_Factor_Core::get_providers();
+
+		$this->assertArrayHasKey( 'Two_Factor_Totp', $actual );
+		$this->assertArrayHasKey( 'Two_Factor_Backup_Codes', $actual );
+		// @todo enable after https://github.com/WordPress/two-factor/issues/427 merges
+		//$this->assertArrayHasKey( 'Two_Factor_WebAuthn', $actual );
+
+		$this->assertArrayNotHasKey( 'Two_Factor_Email', $actual );
+		$this->assertArrayNotHasKey( 'Two_Factor_Dummy', $actual );
+	}
 }

wporg-two-factor.php

@@ -12,3 +12,18 @@
 namespace WordPressdotorg\Two_Factor;
 defined( 'WPINC' ) || die();
 
+add_filter( 'two_factor_providers', __NAMESPACE__ . '\two_factor_providers', 99 ); // Must run after all other plugins.
+
+/**
+ * Determine which providers should be available to users.
+ */
+function two_factor_providers( array $providers ) : array {
+	// Match the name => file path format of input var, but the path isn't needed.
+	$desired_providers = array(
+		'Two_Factor_WebAuthn'     => '',
+		'Two_Factor_Totp'         => '',
+		'Two_Factor_Backup_Codes' => '',
+	);
+
+	return array_intersect_key( $providers, $desired_providers );
+}