fix(memory-graph): stop hit-testing against stale nodes after resize or theme change (#1284)

packages/memory-graph/src/__tests__/spatial-index.test.ts

@@ -54,6 +54,33 @@ describe("SpatialIndex", () => {
 		expect(result).toBe(true)
 	})
 
+	it("hash guard keeps stale objects for a new generation at the same positions", () => {
+		const idx = new SpatialIndex()
+		const genA = [makeNode("a", 100, 100)]
+		idx.rebuild(genA)
+
+		const genB = [makeNode("a", 100, 100)]
+		expect(idx.rebuild(genB)).toBe(false)
+		expect(idx.queryPoint(100, 100)).toBe(genA[0])
+	})
+
+	it("force rebuild swaps the grid to the new node generation", () => {
+		const idx = new SpatialIndex()
+		const genA = [makeNode("a", 100, 100)]
+		idx.rebuild(genA)
+
+		const genB = [makeNode("a", 100, 100)]
+		expect(idx.rebuild(genB, true)).toBe(true)
+		expect(idx.queryPoint(100, 100)).toBe(genB[0])
+	})
+
+	it("force rebuild still refreshes the hash for subsequent unforced calls", () => {
+		const idx = new SpatialIndex()
+		const nodes = [makeNode("a", 100, 100)]
+		idx.rebuild(nodes, true)
+		expect(idx.rebuild(nodes)).toBe(false)
+	})
+
 	it("rebuild detects sub-pixel movements (10x granularity)", () => {
 		const idx = new SpatialIndex()
 		const nodes = [makeNode("a", 100.0, 100.0)]

packages/memory-graph/src/canvas/hit-test.ts

@@ -5,9 +5,10 @@ export class SpatialIndex {
 	private cellSize = 200
 	private lastHash = 0
 
-	rebuild(nodes: GraphNode[]): boolean {
+	// Hash only covers ids/positions, so pass force when the node array identity changes.
+	rebuild(nodes: GraphNode[], force = false): boolean {
 		const hash = this.computeHash(nodes)
-		if (hash === this.lastHash) return false
+		if (!force && hash === this.lastHash) return false
 		this.lastHash = hash
 		this.grid.clear()
 

packages/memory-graph/src/components/graph-canvas.tsx

@@ -97,13 +97,13 @@ export const GraphCanvas = memo<ExtendedGraphCanvasProps>(function GraphCanvas({
 		simulation,
 	}
 
-	// Rebuild nodeMap + spatial index when nodes change
+	// Force the spatial rebuild: a new node generation can keep the same ids/positions
 	useEffect(() => {
 		const map = nodeMapRef.current
 		map.clear()
 		for (const n of nodes) map.set(n.id, n)
 		inputRef.current?.syncNodes(map)
-		spatialRef.current.rebuild(nodes)
+		spatialRef.current.rebuild(nodes, true)
 		renderNeeded.current = true
 	}, [nodes])
 

packages/memory-graph/src/components/memory-graph.tsx

@@ -20,7 +20,6 @@ import type {
 	GraphApiDocument,
 	GraphNode,
 	MemoryNodeData,
-	GraphThemeColors,
 	MemoryGraphProps,
 	ResolvedMemoryGraphLabels,
 } from "../types"
@@ -85,14 +84,7 @@ export function MemoryGraph({
 	)
 	const hoverPopoverZIndex =
 		layering?.hoverPopoverZIndex ?? DEFAULT_HOVER_POPOVER_Z_INDEX
-	const resolvedColors = useGraphTheme(colorOverrides)
-	const colors = useMemo<GraphThemeColors>(
-		() =>
-			colorOverrides
-				? { ...resolvedColors, ...colorOverrides }
-				: resolvedColors,
-		[resolvedColors, colorOverrides],
-	)
+	const colors = useGraphTheme(colorOverrides)
 
 	const [containerSize, setContainerSize] = useState({ width: 0, height: 0 })
 	const [containerBounds, setContainerBounds] = useState<DOMRect | null>(null)