Do you need app.options and app.use(cors()); ??

Hi,

I have a client that is getting a CORS error for preflight. So, we added the"app.options", in addition to the app.use. Do we need to add both for all routes? (nodeJS with Express).

Code in the main JS file in node. This is executed prior to any routes:

app.options('*', cors()) // include before other routes
app.use(cors()); // Header support for Express

Is this redundant? Will the second line cause the preflight to fail or are both necessary? We have a client that is failing the preflight with both Chrome and Edge.

Thanks! Steve

[sinclas]

Hi, I had a feeling that was the case. We only used app.use(cors());, but then out of nowhere, a client of ours is having preflight failure and can’t use our platform. We added the app.options(‘*’, cors()) as a precaution to the preflight issues but they are still having preflight issues in both Chrome and Edge. We are trying to make sure everything on the server side is solid. We have never seen this before and then there is a preflight failure…out of nowhere. There is nothing more we can do on our side, other than suggest a plugin for the client., which is not the best option.

What other options should we pursue if the client is still failing? This is the Chrome error (real web address changed) : ‘https://sampleapi.com/me’ from origin ‘https://sampleeapp.com’ has been blocked by CORS policy: Response to preflight request doesn’t pass access control check: No ‘Access-Control-Allow-Origin’

Any help on this would be appreciated!

thanks. Steve

[andrewdibiasio6]

@sinclas I am having similar issues. Any updates? I actually can see that my server is not providing the “allow-control-access-origin” header. This only happened when I enabled credentials. I also have this issue with edge, firefox, and chrome"