Adversarial review (4 lenses → per-finding verify) of v3 confirmed 6 issues:
- HIGH: splitForLayout({"grid-4":null}) threw a TypeError — null passed the
`!== undefined` guard, then null.cols threw. Since splitForLayout runs on every
grid render, one corrupt localStorage entry would brick the tab UI. Now guards
`!== null && typeof === 'object'`.
- MED: a monitor toggled before the session finished attaching (id still null)
showed the button active while the pane stayed live and sent a resize, and did
not self-correct. onSessionId now reconciles a pending monitor once the id lands.
- MED: renderGutters destroyed + recreated handles on every applyLayout, dropping
the drag listeners if a re-render fired mid-drag. A draggingGutter flag now skips
the rebuild while dragging.
- LOW: grid-presets hardcoded the 1024px breakpoint → now uses GRID_MIN_WIDTH.
Regression tests added (null-split no-throw, attach reconcile, drag survives a
concurrent re-render). typecheck + build:web clean, 1615 tests pass.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Resizable splitters: draggable gutters between grid tracks adjust per-layout
column/row fractions (fr units), applied as an inline grid-template and persisted
(web-terminal:grid-splits). The fraction math (adjustSplit — trades delta between
adjacent tracks, clamps to a minimum, conserves the total) is a pure, unit-tested
helper in grid-layout.ts; the drag translates pixel motion into an fr delta.
Saved presets: public/grid-presets.ts — a toolbar dropdown to save the current
layout + its split under a name, re-apply it in one click, or delete it
(web-terminal:grid-presets). Desktop-only, like the layout toggle.
- grid-layout.ts: layoutTracks, defaultSplit, adjustSplit, tracksToTemplate,
load/saveGridSplits, splitForLayout (validates stored shape).
- tabs.ts: renderGutters/beginGutterDrag/setSplit; applyLayout sets the inline
template; gridArrangement()/applyGridPreset() hooks.
- main.ts: mount the presets dropdown. style.css: gutters + presets menu.
- tests: splitter math + persistence + a stubbed drag repro (1.2fr/0.8fr); presets
persistence + dropdown (save/apply/delete/close). typecheck+build clean, 1612 pass.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
