Fix internal server error on failed social login by redirecting to login page

apps/api/src/app/auth/auth.controller.ts

@@ -2,6 +2,7 @@ import { WebAuthService } from '@ghostfolio/api/app/auth/web-auth.service';
 import { AllowDuringImpersonation } from '@ghostfolio/api/decorators/allow-during-impersonation.decorator';
 import { CustomThrottlerGuard } from '@ghostfolio/api/guards/custom-throttler.guard';
 import { HasPermissionGuard } from '@ghostfolio/api/guards/has-permission.guard';
+import { OAuthCallbackGuard } from '@ghostfolio/api/guards/oauth-callback.guard';
 import { ConfigurationService } from '@ghostfolio/api/services/configuration/configuration.service';
 import { DEFAULT_LANGUAGE_CODE } from '@ghostfolio/common/config';
 import {
@@ -62,13 +63,13 @@ export class AuthController {
   }
 
   @Get('google/callback')
-  @UseGuards(AuthGuard('google'))
+  @UseGuards(OAuthCallbackGuard('google'))
   @Version(VERSION_NEUTRAL)
   public googleLoginCallback(
     @Req() request: Request,
     @Res() response: Response
   ) {
-    const jwt: string = (request.user as any).jwt;
+    const jwt: string = (request.user as any)?.jwt;
 
     if (jwt) {
       response.redirect(
@@ -98,10 +99,10 @@ export class AuthController {
   }
 
   @Get('oidc/callback')
-  @UseGuards(AuthGuard('oidc'))
+  @UseGuards(OAuthCallbackGuard('oidc'))
   @Version(VERSION_NEUTRAL)
   public oidcLoginCallback(@Req() request: Request, @Res() response: Response) {
-    const jwt: string = (request.user as any).jwt;
+    const jwt: string = (request.user as any)?.jwt;
 
     if (jwt) {
       response.redirect(

apps/api/src/guards/oauth-callback.guard.ts

@@ -0,0 +1,21 @@
+import { Logger, mixin, Type } from '@nestjs/common';
+import { AuthGuard, IAuthGuard } from '@nestjs/passport';
+
+export function OAuthCallbackGuard(strategy: string): Type<IAuthGuard> {
+  class OAuthCallbackGuardMixin extends AuthGuard(strategy) {
+    private readonly logger = new Logger(OAuthCallbackGuard.name);
+
+    public override handleRequest(error: Error, user: any) {
+      if (error) {
+        this.logger.error(
+          `Authentication with the ${strategy} strategy has failed: ${error.message}`
+        );
+      }
+
+      // Do not throw, the callback handler redirects to the login page instead
+      return user;
+    }
+  }
+
+  return mixin(OAuthCallbackGuardMixin);
+}