Pit Wall Telemetry · Streaming Feed
A live-updating feed: telemetry rows stream in on a fixed interval until the checkered flag lands as an honest, waitable end state.
Twelve laps stream onto the timing screen. Wait for the checkered flag, not a lucky sleep.
Streaming Feed is a medium Waits & Dynamics challenge on Fun UI Playground. A live-updating feed: telemetry rows stream in on a fixed interval until the checkered flag lands as an honest, waitable end state. It runs entirely in the browser, with no backend. Every interactive element carries a stable id and data-testid prefixed with “live-feed-”, and the techniques it exercises are wait for appended rows, terminal-state waits, aria-live regions, polling assertions.
At a glance
- Category
- Waits & Dynamics
- Difficulty
- medium
- Teaches
- wait for appended rows · terminal-state waits · aria-live regions · polling assertions
- Backend
- None — runs entirely in the browser
- Locators
- Stable
idanddata-testid, prefixedlive-feed-
Selectors on this page
| Locator | What it is |
|---|---|
#live-feed-start ul#live-feed-log #live-feed-item-1 | Start: #live-feed-start · rows land in ul#live-feed-log (role="log") as #live-feed-item-1 … -12 |
#live-feed-count | Live counter in #live-feed-count ("N of 12 laps") |
#live-feed-end | The end state is #live-feed-end (🏁) — wait for it instead of sleeping |
Frequently asked questions
How do I wait for a streaming feed to finish?
Wait for the terminal state, not a duration. Click #live-feed-start, then wait for #live-feed-end (the checkered flag). Rows land in ul#live-feed-log as #live-feed-item-1 … -12 and #live-feed-count reports progress. ?delay=100 speeds the 800 ms interval up for CI.
How do I assert on rows that arrive over time?
Either assert the final state once the flag lands, or poll one specific row's text. The log is a role="log" live region and the twelve laps stream identical rows on every run, so exact per-row assertions are safe here.
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