_updateConnectionIndicator() ran on every keystroke (_reliableSend) and
every ACK (_ackDelivery), unconditionally writing display/className/
textContent/title. During fast typing the rendered output is usually
identical between calls, so those were wasted main-thread DOM writes.
Extracted the branch logic into a pure DOM-free _computeConnectionDescriptor()
returning { display, dotClass, text, title } (every branch/string preserved
verbatim; hidden state normalizes the three non-display fields to '' so the
compare is well-defined). _updateConnectionIndicator() now computes the
descriptor, compares all four fields against a cached _lastIndicatorDescriptor,
and early-returns when unchanged — otherwise caches and writes the DOM exactly
as before (display always; dotClass/text/title only when shown). First call
renders (cache starts null). Perf only, no behavior change.
Tests: test/connection-indicator.test.ts — 9 descriptor cases pinning the
exact strings per state + 4 skip cases (first call writes; two identical calls
write DOM once via counting setters; state change and hidden->shown re-render).
31/31 with input-send-order regression; build, frontend-syntax, prettier clean.
The upstream v1.1.15 merge spliced upstream's transport-object indicator
body onto local's _connectionStatus-based _updateConnectionIndicator()
without defining `transport`, so every transport.* reference threw
ReferenceError on any queued state. That hid the "WS" status and, because
_reliableSend() updates the indicator before _drainSession(), made every
keystroke skip immediate delivery (input flushed only on the 2s sweep =
typing lag).
- Rewrite _updateConnectionIndicator() to show the terminal WebSocket
transport from _wsState (WS / HTTP / WS… / Offline), falling back to the
SSE _connectionStatus only on the idle dashboard.
- Only annotate a backlog (· N queued) above 4 bytes so normal typing no
longer flickers "sending 1B" on each key press.
- test/connection-indicator.test.ts (new): transport labels, the >4B
threshold, an exhaustive never-throws guard for the ReferenceError, and
the _reliableSend -> _drainSession invariant (typing-lag guard).
- test/input-send-order.test.ts: reconcile to local's durable input layer
(the prior coalescing-fallback tests had been failing since 1255e28).
Aamer Akhter