feat: upload_file auto-dispatch change event + wait_for_condition helper

[qiankunli]

Problem

upload_file() uses CDP DOM.setFileInputFiles which sets files at the browser level, but many React component libraries (Arco Design DragUpload, Ant Design Upload, etc.) only react to DOM change events — not CDP-level file setting. This causes uploads to silently stay at 0%.

Additionally, there's no generic way to poll for arbitrary page states (spinner gone, streaming response complete, specific text appeared) without writing a manual for-loop each time.

Changes

upload_file(selector, path, dispatch_change=True)

Dispatches a synthetic change event after DOM.setFileInputFiles by default. This makes React upload components detect the selected files immediately.

• Backward compatible: standard <input type="file"> elements are unaffected by the extra event
• Set dispatch_change=False to opt out if needed

wait_for_condition(js_expr, timeout=15.0, poll=0.5)

Generic JS-expression poller for states that don't map to a single CSS selector:

wait_for_condition("!document.querySelector('.arco-spin-loading')")
wait_for_condition("document.querySelectorAll('.markdown-body h3').length >= 3")
wait_for_condition("document.querySelector('textarea')?.disabled === false")

Returns the truthy value on success, or False on timeout.

cdp() docstring

Clarifies that session_id is a top-level kwarg, not a CDP param — passing it inside params causes 'Message may have string sessionId property' errors.

Context

Discovered while automating Arco Design-based admin pages (file upload to knowledge base) and Notebook chat pages (waiting for SSE streaming to complete). The upload_file fix alone would have saved ~30 minutes of debugging per site.

[cubic-dev-ai]

No issues found across 1 file

_{Re-trigger cubic}