Niklas Mischkulnig

Working on Turbopack at @vercel

[Niklas Mischkulnig @mischnic]

@devongovett @5813cf9e38904f I still very much want to do this! Just haven't found the time yet...

[Next.js @nextjs]

How we're making Turbopack fast.

In this deep dive, @lukeisandberg explains how Turbopack uses incremental caching and compilation so the cost of work scales with your change, not the size of your app.

[Next.js @nextjs]

Learn how we built Turbopack with incremental computation to scale development and builds to Next.js applications of all sizes.
https://t.co/cvlEmRCVKh

[Niklas Mischkulnig @mischnic]

@grhmc So „ui“ has a lockfile?

You should set config.turbopack.root to path.join(__dirname, „..“)

https://t.co/QlLnwn8L10

[Malte Ubl @cramforce]

We introduced a dedicated HackerOne program for Vercel WAF bypasses for CVE-2025-55182 / react2shell
Critical bypass: $50K
https://t.co/90NnL06Vnx

[Niklas Mischkulnig @mischnic]

@rjwadley I think we are gonna change it so that data-urls are by default spec compliant
and you opt into the current behavior with a special mime type

[Niklas Mischkulnig @mischnic]

@rjwadley yes. that is exactly why I went slightly spec-incompliant there. when transpiling css-in-js -> CSS data url import, then it's very useful to have relative imports work.

there's a test case here: https://t.co/BbhqJUBEn3

[Tim @timneutkens]

We've been working on something new:
Turbopack / Next.js bundle analyzer.

It's fully aware of Next.js routes and the Turbopack module graph.

You no longer have to guess where a module is loaded.
It shows the full import stack so that you can easily find where the module is used, not just one path but all paths that lead to the module being included in the bundle.

You can also inspect CSS size and other assets, as well as the server bundles.

Note: Output size shown is without compression (gzip/brotli). We're planning to add that.

For example running it on an open source application:

[Niklas Mischkulnig @mischnic]

@JimsonRai @timneutkens See https://t.co/e1jfTQLUSD, I have a reproduction now and we'll try to fix it soon.

[Niklas Mischkulnig @mischnic]

@decocereus What problem are you running into with polyfills?

[Niklas Mischkulnig @mischnic]

@velddev What issue are you seeing exactly? Can you open a GitHub issue?

[Niklas Mischkulnig @mischnic]

@timneutkens @TrosclairTweets @nextjs This will be fixed by https://t.co/d2QFrKDdrX

[Niklas Mischkulnig @mischnic]

@fuma_nama @rauchg @isukkaw @nextjs What exactly are you missing?
On our radar is most importantly resolver plugins and transformation (i.e. what Webpack loaders do, though not very fast).
Turbopack should implement most of the same semi-standard Webpack https://t.co/1cZtdjoLJ8 HMR API. But indeed not documented.

[Niklas Mischkulnig @mischnic]

@manulpz4 @timneutkens I see, can reproduce the problem on 15.5.4.
It's already fixed on the next@canary versions though.

[Niklas Mischkulnig @mischnic]

@manulpz4 @timneutkens Are you using middleware with the "nodejs" runtime?
And if yes, how are you configuring that? Anything unusual about that `export const config = ...`?
https://t.co/YHaSXlaUhj

[Niklas Mischkulnig @mischnic]

@rsdgpt @convex @openrouter You mean web workers? What exactly wasn't working? Do you have a reproduction by chance?

[Niklas Mischkulnig @mischnic]

@redacted_noah @timneutkens That one does indeed not work, you're running into issue: https://t.co/hEL8E4hJ8Q
Same with Webpack though, so not specific to Turbopack:

[Niklas Mischkulnig @mischnic]

@redacted_noah @timneutkens That write function doesn't exist (and your snippet doesn't work in Node.js either), do you mean

Buffer.alloc(8).writeBigUInt64LE(2n)

maybe? That one does work with both Turbopack and Webpack in Next.js