uWebSockets duplicate set-cookie responses

[nathan-ahn]

Describe the bug

When using uWebSockets.js with Yoga, cookies with multiple values are duplicated.
Example:
name=value0; SameSite=None; Secure, name=value1; SameSite=Strict; Secure -> name=value0; SameSite=None; Secure, name=value1; SameSite=Strict; Secure, name=value0; SameSite=None; Secure, name=value1; SameSite=Strict; Secure

This issue does not appear to occur when running on other servers (tested using Node's server and Express). This problem also does not occur when setting cookies from within uWebSockets.js directly (bypassing Yoga).

Your Example Website or App

https://github.com/nahn20/yoga-graphql-duplicate-cookies

Steps to Reproduce the Bug or Issue

Run one of the demo servers with npm run node, npm run express, or npm run uWebSockets.

Then, while the server is running, run either npm run ping or npm run pingRoot (uWebSockets only) to see the results. These scripts ping the server with a trivial request and log the response and cookies.

Expected behavior

I expected the set-cookie header value to not be duplicated when run on uWebSockets. Additionally, I expected the set-cookie header value to match that of Node and Express.

Screenshots or Videos

No response

Platform

• OS: macOS (issue also occurs on Fargate (Linux) but that was using our full Yoga server rather than the minimal example repository)
• NodeJS: 18.18.2
• graphql-yoga: 5.3.1

Additional context

No response