microlinkhq / browserless / 34779582356

79%

push

github

test(goto): pin user agent client hints across worker scopes (#930)

Shared and service workers read the browser process user agent, so goto's
per-page `Network.setUserAgentOverride` leaves them reporting
`HeadlessChrome` while the page reports `Chrome`. CreepJS reads the
service worker scope first and flags the mismatch.

A browser wide `--user-agent` does close that mismatch, but Chrome answers
it by blanking the high entropy client hints everywhere the per-page
override does not reach: a raw page sends an empty
`Sec-CH-UA-Full-Version-List`, and shared and service workers report
`fullVersionList: []` with `platformVersion: ""`. A page level override
repairs a page, and a worker session override repairs a shared worker, but
a service worker never gets them back: `Network.setUserAgentOverride` is
accepted without effect on its own session, auto-attached or manually
attached alike, and `Emulation` is unavailable there. A `Chrome` user
agent with an empty full version list is unreachable in real Chrome, and
that is the scope CreepJS reads first, so the trade is a worse signal than
the one it removes and the flag is not worth shipping.

What lands instead is the measurement as tests: the client hints stay
pinned in every scope, and the driver keeps asserting it sets no
`--user-agent`, so this cannot regress silently.


Claude-Session: https://claude.ai/code/session_0116zka7w2WKPSi3kqHyVAET

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

1147 of 1361 branches covered (84.28%)

Branch coverage included in aggregate %.

5201 of 6403 relevant lines covered (81.23%)

78647.69 hits per line