FA-31163 / Keyboard interactions / Member archive
Per-key double tap recognizer: Double-tap matching borrows a release timestamp from a different key · case 03
The event trace violates the per key history rule and produces incorrect keyboard state or command output.
Case contract
Case [window,events] with nondecreasing timestamps and events [kind,key,time]. Down repeats do not count. A matched up produces tap and may complete a double if the prior release of the same key is within the inclusive window. Completing a double consumes that prior release. Cancel clears that key, blur clears all state. Return doubles [key,time], held keys and remembered release times. Inputs are finite ordered event traces; return the stated deterministic state. Batch entries are independent. N varies the number of independent input transactions.
Why this case matters
Controlled keyboard event processing model for debugging application event logic.
One recorded failure
Sample boundary fixtureThis sample comes from the broken implementation of a controlled reproducer.
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| double-tap scenario 4 | [[[["B", 13]], [], [["A", 11]], 2], [[["B", 13]], [], [["A", 11]], 2], [[["B", 13]], [], [["A", 11]], 2]] | [[[], [], [["A", 11], ["B", 13]], 2], [[], [], [["A", 11], ["B", 13]], 2], [[], [], [["A", 11], ["B", 13]], 2]] | Failed |
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