4.18.1 causes app to render in a <pre> tag when using unstable_getServerSession

[EvHaus]

Environment

System:
OS: Linux 5.15 Ubuntu 22.04.1 LTS 22.04.1 LTS (Jammy Jellyfish)
CPU: (24) x64 AMD Ryzen 9 3900X 12-Core Processor
Memory: 25.39 GB / 31.32 GB
Container: Yes
Shell: 5.1.16 - /bin/bash
Binaries:
Node: 17.8.0 - ~/.nvm/versions/node/v17.8.0/bin/node
Yarn: 1.22.19 - ~/.yarn/bin/yarn
npm: 8.5.5 - ~/.nvm/versions/node/v17.8.0/bin/npm
npmPackages:
next: 13.0.6 => 13.0.6
next-auth: 4.18.1 => 4.18.1
react: 18.2.0 => 18.2.0

Reproduction URL

https://stackblitz.com/edit/github-61ga3k-prdgby?file=pages%2Fserver.tsx

Describe the issue

After upgrading from 4.18.0 to 4.18.1 I'm seeing a very strange issue where my app no longer renders. Instead, Next renders the HTML of my app in a <pre> tag, so it looks like this:

What I've determined so far:

• 4.18.0 doesn't have this bug
• 4.18.1 and 4.18.3 have this bug
• The issue only happens when using unstable_getServerSession
• The issue only happens when you have logged in and have a session defined

How to reproduce

Check out the Stackblitz link I created. The issue is somewhat reproducible there. The "server" page there has a unstable_getServerSession used in getServerSideProps.

To reproduce the bug:

• Run that Stackblitz example
• Go to the "Server" page in the UI
• Click on "Sign in" and try to sign in to one of the providers (doesn't mattern if you complete this or not)
• Press the browser Back button to go back to the app
• BUG: The UI no longer renders. Instead you get a <pre> tag with all the code of your app

Expected behavior

Bug doesn't happen. Next Auth should render the app as normal.

[balazsorban44]

Thanks, I identified the issue. As a workaround, you can set res.removeHeader("Content-Type") in your getServerSideProps after the unstable_getServerSession call.

The reason this happens is because unstable_getServerSession internally overrides the Content-Type to application/json, while the page using getServerSideProps should always return text/html.

A patch will be out today.

[balazsorban44]

I have an experimental release you can test out! pnpm add [email protected]

[balazsorban44]

A fix should be out for this in 4.18.4.

[EvHaus]

Confirmed 4.18.4 fixes the issue! Thanks for the fast fix. I found a new, different bug with 4.18.x though. Will open a new ticket shortly.