Do not redirect when handling vault_enabled settings, also return false if there is no scope yet

modules/ppcp-api-client/src/Entity/class-token.php

@@ -104,7 +104,11 @@ class Token {
 	 *
 	 * @return bool Whether vaulting features are enabled or not.
 	 */
-	public function vaulting_available() {
+	public function vaulting_available(): bool {
+		if ( ! isset( $this->json->scope ) ) {
+			return false;
+		}
+
 		if ( strpos(
 			$this->json->scope,
 			'https://uri.paypal.com/services/vault/payment-tokens/readwrite'

modules/ppcp-wc-gateway/src/Settings/class-settingslistener.php

@@ -147,15 +147,11 @@ class SettingsListener {
 			return;
 		}
 
-		$redirect_url = admin_url( 'admin.php?page=wc-settings&tab=checkout&section=ppcp-gateway' );
-
 		$token = $this->bearer->bearer();
 		if ( ! $token->vaulting_available() ) {
 			$this->settings->set( 'vault_enabled', false );
 			$this->settings->persist();
-
-			wp_safe_redirect( $redirect_url, 302 );
-			exit;
+			return;
 		}
 
 		/**

tests/PHPUnit/WcGateway/Settings/SettingsListenerTest.php

@@ -0,0 +1,59 @@
+<?php
+
+namespace WooCommerce\PayPalCommerce\WcGateway\Settings;
+
+use WooCommerce\PayPalCommerce\ApiClient\Helper\Cache;
+use WooCommerce\PayPalCommerce\Onboarding\State;
+use WooCommerce\PayPalCommerce\TestCase;
+use Mockery;
+use WooCommerce\PayPalCommerce\Webhooks\WebhookRegistrar;
+use function Brain\Monkey\Functions\when;
+
+class SettingsListenerTest extends TestCase
+{
+    public function testListen()
+    {
+        $settings = Mockery::mock(Settings::class);
+        $setting_fields = [];
+        $webhook_registrar = Mockery::mock(WebhookRegistrar::class);
+        $cache = Mockery::mock(Cache::class);
+        $state = Mockery::mock(State::class);
+
+        $testee = new SettingsListener(
+            $settings,
+            $setting_fields,
+            $webhook_registrar,
+            $cache,
+            $state
+        );
+
+        $_REQUEST['section'] = 'ppcp-gateway';
+        $_POST['ppcp-nonce'] = 'foo';
+        $_POST['ppcp'] = [
+            'client_id' => 'client_id',
+        ];
+        when('sanitize_text_field')->justReturn('ppcp-gateway');
+        when('wp_unslash')->justReturn('ppcp-gateway');
+        when('current_user_can')->justReturn(true);
+        when('wp_verify_nonce')->justReturn(true);
+
+        $settings->shouldReceive('has')
+            ->with('client_id')
+            ->andReturn('client_id');
+        $settings->shouldReceive('get')
+            ->with('client_id')
+            ->andReturn('client_id');
+        $settings->shouldReceive('has')
+            ->with('client_secret')
+            ->andReturn('client_secret');
+        $settings->shouldReceive('get')
+            ->with('client_secret')
+            ->andReturn('client_secret');
+
+        // run
+        $testee->listen();
+
+        // assert
+        $this->assertTrue(true);
+    }
+}