feat(nextjs): Add URL to tags of server components and generation functions issues

[RulaKhaled]

Next.js’s uses an internal AsyncLocalStorage (ALS) to share minimal request context—it deliberately does not populate the full Request object or URL in ALS, so only headers (Referer, x-forwarded-host, x-forwarded-proto) are available at runtime in Server Components.

To still capture a usable URL for metadata we use a three-step best-effort fallback:

1. Referer header
Use it as the fully qualified URL if present (note: this could be omitted by the browser).
2. Proxy headers + route
Reconstruct protocol://host from x-forwarded-proto / x-forwarded-host (or host), then append the normalized component route with substituted [param] values. Query strings and fragments are TBD as query params fetched from args are always undefined for some reason, this needs investigation
3. Span fallback
As a last resort, use the parent span’s http.target attribute (which contains the path and query) from the root HTTP span.

closes: https://linear.app/getsentry/issue/JS-487/capture-requesturl-for-nextjs-server-spans

[chargome]

LGTM! Could you also add a test case for a generation function in of the e2e tests?

[mydea]

l: this can be simplified to:

if (typeof spanData.data['http.target'] === 'string') {
  pathname = spanData.data['http.target'];
}

spanData.data should never be empty I believe, and we can just check for stringiness and then avoid the typecase below :)

[mydea]

same here as above :)

[mydea]

l: I would always mention here if things are only exported for tests, for clarity. In this file, I believe only getSanitizedRequestUrl is actually used, all the other exports are for tests only right? By mentioning this with each export is is easier to follow why things are exported (vs. "hey can I un-export this because it is not actually used anyhwere?")