UA Ledger · Playable Test Bench · draft for review

Count one install action when the end card is tapped repeatedly

Teaching laboratory. Cases run in this page against the authored functions. This is not a device panel, network approval, analytics-delivery proof or campaign result. Inputs are synthetic.

A double tap on an end card should not dispatch duplicate store-opening actions. This fixture uses a real EventTarget to check a once-only handler while keeping every action inside the laboratory.

Primary documentation: MDN: cta once (body read 2026-09-19).

Cases

What a pass does not prove

Passing this test proves one listener fires once for the supplied event sequence. It does not prevent a different listener from dispatching the same business action, and it does not validate an ad SDK's click API. An application-level idempotency guard may still be appropriate when several activation paths share one action.