FA-21799 / Assistive announcements / Member archive

Disabling braille affects pending deliveries but not future ones · case 04

The announcement trace violates the stated dual-channel-barrier contract.

Member previewVariant 4 · 3 implementations · 9 checks per implementation

Case contract

An announcement delivery couples speech and braille with per-message receipts. Submit creates [text,speechDone=False,brailleDone=False]. Speech and braille ACK set only their channel. Commit emits completion once only when both acknowledged and removes message. Disable-braille marks pending braille complete and affects future submissions; enable only affects future submissions. Replace text resets both receipts according to current enabled channels. Cancel drops one pending item. Report completion text, pending receipts and braille enabled.

Why this case matters

Deterministic controlled model of assistive announcement delivery.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
trace-5	`[[], [["a", "pendingpendingpendingpending", false, true], ["b", "future", true, false]], true]`	`[["future"], [["a", "pendingpendingpendingpending", false, true]], true]`	Failed

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