- Exclude popped-out (detached) sessions from the split picker:
SplitTerminalPane._sendResize() has no yield-to-detached-window check
the way the primary pane's sendResize() does, so splitting against a
detached session put its own window and Pane B in a fight over the
same PTY's dimensions. Simplest fix per the review: keep them out of
buildSplitPickerSessions() entirely.
- Show a visible dead state when Pane B's WebSocket drops. onData
already silently discards keystrokes while the socket isn't OPEN
(there is no reconnect for v1), so a dropped socket left the pane
looking normal while it quietly ate everything typed into it.
- openSplitPane() returns early with no active session, so a split
triggered from the home screen no longer creates and connects Pane B
behind the opaque welcome overlay with nothing to show for it.
- onMove() during a divider drag now bails when the split has
auto-collapsed mid-drag (the other pane's session ending) instead of
throwing on `divider.parentElement` being null.
- Promote Pane B via `selectSession(id, { auto: true })` when Pane A's
session ends — this is an app-driven selection, not the user clicking
a tab, so it must not spend the promoted session's idle alert.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
test/split-pane-auto-collapse.browser.test.ts covers "Pane B's session ends"
in a real Chromium, but that suite is excluded from the npm test CI gate.
The "Pane A's session ends, Pane B gets promoted" branch had no coverage
anywhere, and it is the one branch whose correctness depends on exact
ordering: _splitSessionId must be captured BEFORE closeSplitPane() runs
(which nulls it) or the promoted session id is lost. Loads terminal-split.js
via `vm` against a minimal fake CodemanApp (same technique as
test/session-close-fallback.test.ts), and pins all three branches (Pane A
ends, Pane B ends, unrelated session ends) plus that the original
_onSessionDeleted always still fires.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>