test: harden sidebar overlay width tests against CI rebuild race

Remove an unnecessary prebuild step in SnapFX sidebar overlay width/resize-handle tests before reflective sidebar icon clicks.

The prebuild can initialize SnapFX root state and allow icon-click handling to schedule an async sidebar rebuild (
equestRebuild()), which races the final scene build on CI and can fail at
ew Scene(snapFX.buildLayout(), ...).

Document the test hardening in status/roadmap/done/changelog notes and keep current test counts consistent.

Author: Beowolve

CHANGELOG.md

@@ -8,6 +8,7 @@ The changelog is grouped by release tags (`vX.Y.Z`) and includes an `Unreleased`
 
 ### Build and Test
 - ✅ Added `DockDebugOverlayTest` coverage for HUD layout defaults (managed pref-sized panel + background presence) and live target/zone diagnostics refresh when drag data mutates in place.
+- ✅ Hardened `SnapFXTest` sidebar overlay width/resize-handle tests against a CI-only async sidebar rebuild race by removing an unnecessary prebuild step before reflective sidebar icon clicks.
 
 ### Framework and UI
 - ✅ Fixed `DockDebugOverlay` HUD rendering and diagnostics behavior used by MainDemo debugging: the HUD panel now lays out correctly with visible background (no top-left clipping), and target/zone text updates live during active drags instead of staying at `none`.

DONE.md

@@ -82,12 +82,13 @@ SnapFX has been fully implemented with core functionality and is production-read
 - ✅ `DockDragServiceTest` (8 tests) - D&D visibility, tab-hover activation, float-detach callback behavior, and ESC drag-cancel handling
 - ✅ `DockFloatingWindowTest` (31 tests) - Floating title-bar controls, context-menu behavior (attach/pin icons + attach action), floating-header sidebar move-menu callback forwarding, pin behavior, icon rendering/sync regression coverage, single-node float-menu policy, maximize/restore interaction behavior, scene-level drag continuity (including release/reset and non-primary guard behavior), resize-min constraints, interactive-target cursor reliability, and floating/main edge snapping behavior (including overlap-guard, adjacent-edge cases, and main-window shadow-inset compensation)
 - ✅ `DockFloatingSnapEngineTest` (6 tests) - Snap candidate scoring, overlap-aware candidate generation, and shadow-inset compensation coverage
-- ✅ `MainDemoTest` (24 tests) - Application icon resources, menu icon behavior, sidebar menu/list helper coverage for Phase-C manual controls, sidebar settings width-control API-parity wiring (including `DockSideBarMode` settings control), debug/settings outer-split divider-stability regression coverage, demo shortcut wiring, floating snap-target settings resolution coverage, load-error message formatting, owner-aware error-alert behavior, FileChooser helper coverage for shared layout/editor chooser configuration, and named theme-catalog/resource coverage
+- ✅ `MainDemoTest` (23 tests) - Application icon resources, menu icon behavior, sidebar menu/list helper coverage for Phase-C manual controls, sidebar settings width-control API-parity wiring (including `DockSideBarMode` settings control), debug/settings outer-split divider-stability regression coverage, demo shortcut wiring, floating snap-target settings resolution coverage, load-error message formatting, owner-aware error-alert behavior, FileChooser helper coverage for shared layout/editor chooser configuration, and named theme-catalog/resource coverage
 - ✅ `DemoNodeFactoryTest` (3 tests) - Unknown-node fallback strategy coverage (framework placeholder vs. demo custom fallback), plus SnapFX integration coverage for unsupported-type recovery with the default demo factory
 - ✅ `AboutDialogTest` (2 tests) - About dialog resources and credit link targets
 - ✅ `EditorCloseDecisionPolicyTest` (5 tests) - Deterministic close-decision behavior for dirty editor nodes
 - ✅ `MarkdownDocumentationConsistencyTest` (12 tests) - Documentation consistency guardrails
 - ✅ CI flake guard for critical interaction suites (`SnapFXTest`, `DockFloatingWindowTest`, `DockDragServiceTest`) runs 3x per CI execution
+- ✅ `SnapFXTest` sidebar overlay width/resize-handle tests no longer prebuild the layout before reflective sidebar icon clicks, avoiding a CI-only async `requestRebuild()` race before the final scene build
 - ✅ All tests passing (314/314) ✅
 - ✅ **Testing Policy** established (TESTING_POLICY.md)
 - ✅ Mandatory regression tests for all bug fixes

ROADMAP.md

@@ -57,6 +57,7 @@ This roadmap lists planned work only; completed/fixed history is tracked in `CHA
 - ✅ **Floating drag-state regression hardening**: Added scene-level drag release/reset and non-primary activation guard coverage for floating title-bar movement
 - ✅ **Persistence edge-case hardening**: Added complex floating snapshot roundtrip coverage and invalid floating snapshot validation/no-partial-apply tests
 - ✅ **CI flake guard for critical interactions**: CI now reruns `SnapFXTest`, `DockFloatingWindowTest`, and `DockDragServiceTest` three times per run
+- ✅ **Sidebar overlay width test CI race hardening**: `SnapFXTest` overlay-width/resize-handle tests avoid prebuilding `SnapFX` before reflective sidebar icon clicks, preventing an async sidebar `requestRebuild()` race before the final scene build on CI
 - ✅ **Floating reattach structure hardening**: Added three-window floating-layout detach/attach roundtrip regression coverage (top-left/top-right/bottom nodes), plus detach-close-remaining-attach host-restore fallback cases
 
 **Estimated Time**: Completed

STATUS.md

@@ -149,7 +149,7 @@
 - ✅ DockGraphTest (69 tests, +11 regression tests plus sidebar model coverage) - Includes sidebar width preference defaults/validation/lock-policy coverage
 - ✅ DockLayoutSerializerTest (21 tests) - Includes strict load-failure diagnostics for blank content, malformed JSON, missing required fields, invalid tab selection metadata, unknown-node placeholder diagnostics, unsupported-type recovery with optional factory custom fallback, and sidebar persistence/restore-anchor/width roundtrip coverage (including legacy width fallback)
 - ✅ DockLayoutEngineTest (36 tests) - Includes tab/header/splitter context-menu coverage, representative container-tab title/icon behavior, float-availability policy checks, sidebar move-to-sidebar context-menu callback/lock-state coverage, hidden sidebar move-menu state when framework sidebar callbacks are unavailable, header-context-menu dismiss-on-press regression coverage, and tiny-bounds drop-zone clamp regression coverage
-- ✅ **SnapFXTest (94 tests)** - Hide/Restore + Floating Window API tests plus configurable shortcut behavior, floating-window snap API propagation/validation, side-bar facade API behavior (pin/restore, lock-aware pinned-open state, save/load roundtrip preservation), side-bar panel width API/roundtrip coverage, framework sidebar build-layout rendering structure coverage (collapsed strip vs. pinned/overlay panels, resize handle presence, width runtime clamping, right-overlay resize-handle pick/z-order regression coverage, and sidebar visibility mode rendering behavior for `AUTO`/`ALWAYS`/`NEVER`), configurable pinned-sidebar active-icon collapse policy coverage, sidebar-restore placement regression coverage for collapsed tab-parent fallback, sidebar strip/panel context-menu action and lock-state coverage, invalid-load failure handling, persistence edge-case coverage for complex floating snapshots, unknown-type layout recovery, unresolved floating-sub-layout D&D detach behavior, floating reattach placement restore/fallback behavior for both float-button and unresolved-drag detach paths, three-window floating-layout detach/attach roundtrip regression coverage (top-left/top-right/bottom cases), detach-close-remaining-attach host-restore fallback coverage, and theme stylesheet API behavior (initialize auto-apply + runtime switching + named theme catalog exposure)
+- ✅ **SnapFXTest (94 tests)** - Hide/Restore + Floating Window API tests plus configurable shortcut behavior, floating-window snap API propagation/validation, side-bar facade API behavior (pin/restore, lock-aware pinned-open state, save/load roundtrip preservation), side-bar panel width API/roundtrip coverage, framework sidebar build-layout rendering structure coverage (collapsed strip vs. pinned/overlay panels, resize handle presence, width runtime clamping, right-overlay resize-handle pick/z-order regression coverage, sidebar overlay width/resize-handle CI race hardening in tests, and sidebar visibility mode rendering behavior for `AUTO`/`ALWAYS`/`NEVER`), configurable pinned-sidebar active-icon collapse policy coverage, sidebar-restore placement regression coverage for collapsed tab-parent fallback, sidebar strip/panel context-menu action and lock-state coverage, invalid-load failure handling, persistence edge-case coverage for complex floating snapshots, unknown-type layout recovery, unresolved floating-sub-layout D&D detach behavior, floating reattach placement restore/fallback behavior for both float-button and unresolved-drag detach paths, three-window floating-layout detach/attach roundtrip regression coverage (top-left/top-right/bottom cases), detach-close-remaining-attach host-restore fallback coverage, and theme stylesheet API behavior (initialize auto-apply + runtime switching + named theme catalog exposure)
 - ✅ DockGraphSplitTargetDockingTest (1 test)
 - ✅ DockDragServiceTest (8 tests) - D&D visibility, tab-hover activation, float-detach callback behavior, and ESC drag-cancel handling
 - ✅ DockFloatingWindowTest (31 tests) - Floating title bar controls, context menu behavior (attach/pin icons + attach action), floating-header sidebar move-menu callback forwarding, pin behavior, icon rendering/sync regression coverage, single-node float-menu policy, maximize/restore interaction behavior, scene-level drag continuity (including release/reset and non-primary guard behavior), resize-min constraints, interactive-target cursor reliability, and floating/main edge snapping behavior (including overlap-guard, adjacent-edge cases, and main-window shadow-inset compensation)

src/test/java/com/github/beowolve/snapfx/SnapFXTest.java

@@ -1533,7 +1533,7 @@ void testOverlaySideBarPanelUsesConfiguredWidthAndRendersResizeHandle() {
         snapFX.dock(tool, main, DockPosition.RIGHT);
         snapFX.pinToSideBar(tool, Side.LEFT);
         snapFX.setSideBarPanelWidth(Side.LEFT, 420.0);
-        snapFX.buildLayout();
+        // Prebuilding here can schedule an async sidebar rebuild via icon-click handling and race the next buildLayout().
         invokeSideBarIconClick(snapFX, Side.LEFT, tool);
 
         Scene scene = new Scene(snapFX.buildLayout(), 800, 600);
@@ -1558,7 +1558,7 @@ void testRightOverlaySideBarResizeHandleIsPickableAndUpdatesWidth() {
         snapFX.dock(tool, main, DockPosition.RIGHT);
         snapFX.pinToSideBar(tool, Side.RIGHT);
         snapFX.setSideBarPanelWidth(Side.RIGHT, 300.0);
-        snapFX.buildLayout();
+        // Keep rootContainer uninitialized until the final scene build to avoid async rebuild races in CI.
         invokeSideBarIconClick(snapFX, Side.RIGHT, tool);
 
         Scene scene = new Scene(snapFX.buildLayout(), 1000, 700);