Null symbol in style tag

[IKolosynskyi]

Hi!

I am using @emotion,

    "next": "^9.5.5",
    "@emotion/cache": "^11.7.1",
    "@emotion/react": "^11.7.1",
    "@emotion/styled": "^11.6.0",

with CacheProvider

export const emotionCache = createCache({
	key: "css-cache",
	speedy: false,
});

Also, the web site is connected to yandex webvisor which, in some way, crawl and grab style tags.
That's how I see style tag

That's how it looks like in webvisor

Have you ever seen these symbols in style tag? If no, is there any way to provide own render function in which I can define the style tag format so I will be sure that there is no other artifacts except css and data attribute. This data-s looks strange to me.

Thanks in advance!

[srmagura]

Here is the code that adds the data-s attribute. As you can see, the attribute's value is an empty string — there are no weird characters.

This seems like a Yandex problem to me, but let me know if you think otherwise.

[IKolosynskyi]

Thanks, I will analyze this question a bit more but looks like it's really not related to the library.
But I am still curios, why do you need empty data-s attribute?

[srmagura]

My understanding from reading the code is that it is an internal marker used by Emotion to facilitate hydration of server-rendered <style> tags.

[Andarist]

Yes, exactly - this is a marker added during hydration that makes sure that no other instance of Emotion tries to hydrate those already hydrated elements.

[Andarist]

That being said - I'm not sure how it's reported like this. We are setting the value of this attribute to an empty string:

emotion/packages/cache/src/index.js

Line 80 in d253163

node.setAttribute('data-s', '')