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houseplan-card/docs/testing-notes/mutation-browser-guards.md
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Claudeandclaude[bot] 4091d83af3 fix(editor): a render no longer restarts a failed runtime load (#757)
The lazy-runtime contract (#353) says a non-terminal failure waits for
the next explicit intent and that there are no background retries. But
_renderBody calls ensure() on every repaint while a surface waits for
the editor or onboarding runtime, and to the loader that call was
indistinguishable from an intent. Surfaces the core opens without the
runtime - the kiosk size dialog after a 3 s hold, the floor import
wizard on an empty plan, a dialog a warm remount revives - therefore
turned one failure into a loop: the loader's own state change, the
toast and its expiry, every hass tick repainted, started a new cycle
and showed a new toast every ~3.5 s. A wall tablet whose old hashed
chunks answer 404 after an integration update sat in that loop forever.

EditorRuntimeLoader.ensure takes an intent: the render calls it as
'reconcile'. A reconcile starts the first cycle a surface needs, but
after a non-terminal failure it returns false without loading until an
explicit ensure() - a tab, an opener, _requestMode, "Add space" - has
started a new cycle. Explicit calls, the terminal fingerprint failure,
ready and an in-flight cycle behave as before, for every loader
instance. The card's render lines stay line-neutral.

smoke_lazy_editor_chunk gains the three surfaces offline through their
real paths (a 3 s touch hold on a kiosk card, an empty plan pushed by
the server, General settings revived by a remount): one cycle, one
notice and an idle loader over 8 s, then the Plan tab and "Add space"
heal. On dev: 4 requests / 3 notices, 6 / 2 and 3 / 2. The loader unit
test pins reconcile versus intent; the mutant
render-reconcile-restarts-editor-runtime-cycle is guarded by the smoke.

Issue: #757
User-Visible: yes
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018qZfe7YS4rqEMKoVeS3GKd
2026-10-01 12:12:15 +00:00

12 KiB

Browser guards mutation registry (#659)

This is the reviewed classification of every mutation witness that still needs a browser. The executable limit is 200; mutation-gate --check, npm run inventory and the unit contract all read this same inventory. A new browser guard must be added deliberately under one reason below, and its mutant because must explain the concrete browser-only invariant.

Converted witnesses are not listed here: their registry guard names an explicit node --test suite plus test/mutation-browser-offload.test.mjs, and every converted mutant is run once to prove that the Node witness actually kills it.

Category Count Why a browser is still required
Performance threshold 4 The witness measures real browser wall-time or frame work; a pure assertion cannot prove the budget.
Browser harness integrity 4 The mutation breaks page-error, round-trip or page-registration observation in the browser harness itself.
Paint, cascade and layer composition 26 The invariant depends on computed CSS, SVG paint, clipping, stacking or pixels produced by Chromium.
Pointer geometry and trusted interaction 45 The invariant depends on hit testing, pointer capture, touch/keyboard dispatch or live DOM geometry.
Responsive DOM layout 36 The invariant depends on measured element boxes, responsive breakpoints, native/HA dialog shells or focusable target size.
Custom-element and HA browser lifecycle 89 The invariant crosses Lit/custom-element lifecycle, browser storage/events, lazy loading or a complete HA-card state transition.
Total 204 / 200 Growth above the cap fails mutation-gate --check.

Measured effect

The measurements below are GitHub-hosted Linux runs from 2026-09-27. They are recorded separately from the policy limit: the limit proves that browser guards cannot grow unnoticed, while timings show the effect actually observed on the shared runners.

Measurement Before After Observed change
Full-registry wall time 54:18 (1,017 mutants) 48:08 (1,028 mutants) -6:10 (-11.4%), despite 11 additional mutants
Sum of the six Each test catches its breakage steps 4:17:19 4:12:32 -4:47 (-1.9%)
Longest full-registry shard step 50:45 45:13 -5:32 (-10.9%)
Same converted-witness slice, aggregate time 33:43.9 12:07.7 -21:36.2 (-64.0%)
Same converted-witness slice, critical shard 8:05.1 2:19.3 -5:45.8 (-71.3%)

The candidate slice compares the same 83 converted mutant ids in the baseline full-registry log and in the S7 candidate Validate 36316464432. It sums the interval between consecutive per-mutant completion timestamps on each of the six shards. One of the 84 converted ids, active-tab-not-revealed, was the first completed mutant in its shard, so the log cannot isolate its time from clean-guard setup and it is excluded from both sides. The complete candidate run, which also selected registry/tooling mutants outside this converted slice, finished in 10:03.

The original estimate of three to four hours saved on a full-registry run is not supported by this A/B evidence. The directly converted slice is materially faster, but registry growth and shared-runner variance consume most of that gain in the end-to-end total; only the measured reductions above are claimed.

Reviewed per-mutant inventory

Performance threshold

The witness measures real browser wall-time or frame work; a pure assertion cannot prove the budget.

  • junction-limit-p3-quadratic-again
  • junction-limit-p4-bruteforce-again
  • wall-draw-full-preflight-again
  • wall-draw-wall-artifact-discarded

Browser harness integrity

The mutation breaks page-error, round-trip or page-registration observation in the browser harness itself.

  • benchmark-page-verdict-unwatched
  • report-page-errors-skips-round-trip
  • smoke-guard-blind-to-tail
  • smoke-guard-forgets-to-register-pages

Paint, cascade and layer composition

The invariant depends on computed CSS, SVG paint, clipping, stacking or pixels produced by Chromium.

  • daycycle-outline-not-promoted
  • daycycle-outline-promoted-on-inner-paper
  • daycycle-static-outline-promoted-on-inner-paper
  • decor-restored-below-room-fills
  • device-keyboard-bypasses-click-path
  • device-long-value-ellipsis-restored
  • device-unavailable-hover-restored
  • golden-filled-tunnel-removed
  • golden-lamp-out-of-reach
  • hatch-static-renderer-untouched
  • hatch-stroke-not-scaled
  • hatch-zoom-compensation-back
  • iso-first-frame-reveals-flat-during-lazy-load
  • iso-room-label-44-box-centres-name
  • iso-sun-card-drops-occluders
  • iso-sun-flat-wedges-remain
  • iso-theme-dark-wall-rule-returns
  • stage3-w4-device-target-loses-44px-floor
  • stage3-w5-runtime-nudge-writes-storage
  • stage3-w6-no-borders-keeps-raised-plates
  • stage3-w7-sun-state-enters-structural-key
  • sun-ray-origin-cache-ignored
  • sun-ray-origin-save-forced-inner
  • value-static-icon-keeps-live-vacuum
  • value-static-icon-keeps-route-warning
  • value-static-icon-keeps-vacuum-overlay

Pointer geometry and trusted interaction

The invariant depends on hit testing, pointer capture, touch/keyboard dispatch or live DOM geometry.

  • align-guides-exclude-dead-source
  • align-point-reads-frozen-snapshot
  • decor-default-style-debounce-cut
  • decor-default-style-seed-cut
  • decor-keyboard-nudge-drops-focus-dialog-guards
  • decor-keyboard-nudge-reruns-magnet
  • dense-device-hit-browser-skips-painted-priority
  • double-fit-bypasses-canonical-fit-all
  • furniture-art-editor-adopt-skipped
  • furniture-edge-handles-steal-the-corner
  • furniture-exterior-surface-removed
  • furniture-shift-listeners-not-attached
  • furniture-wall-runtime-drops-drag-side
  • furniture-wall-runtime-drops-raw-intent
  • live-pinch-compositor-demoted-on-active-lit-commit
  • opening-dimension-overlay-hidden
  • opening-search-hides-none
  • opening-search-select-not-wired
  • placement-accepts-any-mouse-button
  • reorder-skips-materialization
  • resize-history-boundary-repair-removed
  • resize-label-uses-old-room-gear-centre
  • resize-labels-hide-narrow-area
  • resize-pointer-capture-removed
  • resize-preview-reject-silent
  • room-fit-html-overlay-jumps-ahead
  • room-fit-pan-release-reaccepted
  • room-fit-persists-zoom
  • safe-resize-commit-preflight-bypassed
  • sections-editor-transition-uses-window-height
  • sections-grid-drops-stage-flex-chain
  • sections-grid-falls-back-to-viewport-height
  • sections-resize-drops-stage-refit-observer
  • space-card-decor-capability-change-not-adopted
  • space-card-decor-capability-downgrade-does-not-clear-assets
  • tab-drag-outlives-the-card
  • tab-drag-survives-release-outside
  • tab-drag-target-follows-captured-source
  • tab-drop-indicator-always-before
  • tab-drop-outside-commits-last-target
  • tab-reorder-not-persisted
  • touch-pinch-marker-hold-rearmed
  • touch-pinch-zoom-persists-per-frame
  • unavailable-toggle-stays-silent
  • wall-draw-rejection-rollback-skipped

Responsive DOM layout

The invariant depends on measured element boxes, responsive breakpoints, native/HA dialog shells or focusable target size.

  • dialog-ha-disconnected-reject-reopen-enabled
  • dialog-ha-rejected-close-reopen-disabled
  • dialog-native-reconnect-recovery-disabled
  • dialog-native-surface-stretches-to-viewport
  • dialog-native-update-recovery-disabled
  • fit-house-hidden-walls-vote
  • grid-scale-imperial-roundtrip-drift
  • grid-scale-opening-hit-unscaled
  • grid-scale-opening-symbol-unscaled
  • grid-scale-plan-chrome-unscaled
  • grid-scale-static-factor-missing
  • header-menu-item-below-44
  • header-menu-outside-tap-reaches-plan
  • hidden-room-names-compact-svg-fallback
  • hidden-room-names-full-svg-fallback
  • hidden-room-names-iso-override
  • hp-dialog-ignores-flex-content
  • panel-readonly-empty-bypasses-write-capability
  • phone-editor-close-hidden-with-mode-buttons
  • phone-header-at-tablet-width
  • phone-header-shows-title
  • phone-header-wraps
  • static-card-descendants-hit-testable
  • summary-dialog-drops-flex-content
  • summary-picker-hot-add-stays-filtered
  • tab-editing-without-write-access
  • toolbar-active-highlight-stops-at-tab
  • toolbar-close-back-inside-tab
  • toolbar-close-hidden-at-medium-width
  • toolbar-close-slot-collapses-outside-editor
  • toolbar-close-slot-idle-focusable
  • toolbar-close-slot-leaves-mode-group
  • toolbar-close-target-below-24
  • toolbar-device-count-returns
  • toolbar-mode-zoom-gap-regresses
  • warm-dialog-drops-transferred-baseline

Custom-element and HA browser lifecycle

The invariant crosses Lit/custom-element lifecycle, browser storage/events, lazy loading or a complete HA-card state transition.

  • accepted-marker-rolled-back-by-layout-failure
  • area-relocation-clears-whole-history
  • area-relocation-loses-position-on-refusal
  • backdrop-busy-dismiss-races-decision
  • backdrop-downscale-drops-alpha
  • backdrop-phase2-falls-back-to-original
  • backdrop-probe-always-safe
  • barrier-cache-never-invalidated
  • camera-anchor-from-presented
  • camera-cancel-loses-zoom
  • child-readd-clears-parent-tombstone
  • cold-view-toggle-delegated-to-runtime
  • cold-view-vacuum-mapid-delegated
  • color-picker-confirm-click-through
  • color-picker-invalid-confirm-latch-removed
  • config-updated-event-ignored
  • confirm-dialog-loses-alertdialog
  • current-rejected-physical-write-keeps-optimistic-wall
  • danger-confirm-back-into-the-branch
  • danger-confirm-lost-space-request-guard-removed
  • danger-confirm-lost-space-transition-cancel-removed
  • danger-confirm-uses-last-rendered-language-gate
  • danger-confirm-warm-language-guard-removed
  • danger-confirm-warm-transition-cancel-removed
  • daycycle-programmatic-camera-skips-safe-outline
  • device-echo-keeps-local-noncanonical
  • device-focus-tooltip-blur-cleanup-removed
  • device-focus-tooltip-handler-removed
  • device-focus-tooltip-room-hover-overwrites
  • device-inbox-batch-rollback
  • household-enter-stops-acting
  • household-marker-drops-keyboard-reach
  • device-markers-rendered-without-keys
  • device-pointer-leave-clears-focus-fallback
  • device-position-cancel-routed-to-commit
  • discovery-reset-writes-a-copy
  • editor-neutral-escape-does-not-exit
  • empty-space-cleanup-disabled
  • fixed-floor-transition-guard-bypassed
  • french-locale-wrong-dictionary
  • hp-dialog-escape-does-not-close
  • junction-limit-baseline-cache-stale
  • junction-limit-candidate-fail-open
  • junction-limit-write-gate-removed
  • locale-failure-toast-dropped
  • marker-reject-keeps-optimistic-candidate
  • marker-rollback-keeps-enqueue-time-revision
  • moon-static-clock-tick-off
  • namespace-loader-returns-english
  • near-axis-authoring-snap-bypassed
  • onboarding-loader-skips-namespace-ensure
  • openings-rendered-without-keys
  • plan-only-preview-label-hidden
  • plan-room-area-icon-hidden
  • plan-room-area-icon-navigates
  • plan-upload-client-limit
  • plan-upload-guard-original
  • plan-upload-reduced-over-limit-staged
  • post-write-tail-runs-on-refused-gate
  • readonly-view-syncs-new-devices
  • render-invalidation-renders-irrelevant-ha
  • render-reconcile-restarts-editor-runtime-cycle
  • reopened-room-from-registry-space
  • room-accept-leaves-coincident-partitions
  • room-gear-second-touch-keeps-drag
  • room-settings-click-does-not-open
  • room-tooltip-off-skips-pointer-modality
  • rooms-rendered-without-keys
  • rooms-rendered-without-space-key
  • same-space-room-change-recenters
  • space-create-hidden-display-override
  • stairs-view-pan-opens-target-floor
  • support-invalid-response-leaks-issued-token
  • support-stale-preview-response-revives-consent
  • support-timeout-claims-success
  • vacuum-overlay-back-to-the-dock-space-filter
  • volumetric-kiosk-ignores-setting
  • view-current-space-aria-removed
  • wall-face-apply-skips-overlap-guard
  • wallthick-hit-narrowed
  • writer-history-skips-finished-chain-normalization
  • zigbee-topology-endpoint-cleanup-skipped
  • zigbee-topology-endpoint-elevation-removed
  • zigbee-topology-hovered-endpoint-elevation-removed
  • zigbee-topology-overlay-double-live-projection
  • zigbee-topology-overlay-layer-lowered
  • zigbee-topology-unknown-casing-gaps-filled
  • zigbee-topology-unknown-casing-removed
  • zigbee-topology-unrelated-markers-raised