fix(layout): preserve imported instance child bounds

packages/core/src/layout/apply.ts

@@ -49,6 +49,10 @@ function updateChildFromYoga(graph: SceneGraph, child: SceneNode, yogaChild: Yog
   })
 }
 
+function preservesImportedInstanceInternals(child: SceneNode): boolean {
+  return child.type === 'INSTANCE' && child.source.format === 'fig'
+}
+
 function recomputeGridChild(
   graph: SceneGraph,
   child: SceneNode,
@@ -90,6 +94,8 @@ export function applyYogaLayout(
 
     updateChildFromYoga(graph, child, yogaChild)
 
+    if (preservesImportedInstanceInternals(child)) continue
+
     if (child.layoutMode !== 'NONE') {
       if (child.layoutMode === 'GRID' && child.visible && child.layoutPositioning !== 'ABSOLUTE') {
         computeLayout(graph, child.id)

tests/engine/io/fig/roundtrip/exhaustive.test.ts

@@ -1,4 +1,4 @@
-import { beforeAll, afterAll, describe, expect, test, spyOn } from 'bun:test'
+import { beforeAll, afterAll, describe, expect, test, spyOn, setDefaultTimeout } from 'bun:test'
 
 import { unzipSync } from 'fflate'
 
@@ -24,6 +24,7 @@ import {
 } from './helpers'
 
 let dateSpy: { mockRestore(): void } | undefined
+setDefaultTimeout(180_000)
 beforeAll(() => {
   dateSpy = spyOn(Date.prototype, 'toISOString').mockReturnValue('2026-05-24T12:00:00.000Z')
 })

tests/engine/layout/auto-layout/nested/basic.test.ts

@@ -94,4 +94,63 @@ describe('nested auto layout', () => {
     expect(outerChildren[0].y).toBe(0)
     expect(outerChildren[1].y).toBe(40)
   })
+
+  test('computeAllLayouts preserves fixed children inside instances', () => {
+    const graph = new SceneGraph()
+    const page = pageId(graph)
+    const outer = autoFrame(graph, page, {
+      width: 500,
+      height: 300,
+      paddingTop: 20,
+      paddingBottom: 20
+    })
+    const instance = graph.createNode('INSTANCE', outer.id, {
+      width: 120,
+      height: 120,
+      layoutMode: 'HORIZONTAL',
+      primaryAxisSizing: 'FIXED',
+      counterAxisSizing: 'FIXED',
+      paddingTop: 20,
+      paddingBottom: 20
+    })
+    graph.updateNode(instance.id, { source: { ...instance.source, format: 'fig' } })
+    const fixedChild = autoFrame(graph, instance.id, {
+      width: 80,
+      height: 80,
+      paddingTop: 1665,
+      paddingBottom: 1665
+    })
+
+    computeAllLayouts(graph, page)
+
+    const childNode = getNodeOrThrow(graph, fixedChild.id)
+    expect(childNode.height).toBe(80)
+    expect(childNode.y).toBe(0)
+  })
+
+  test('computeAllLayouts relayouts user-created instance children', () => {
+    const graph = new SceneGraph()
+    const page = pageId(graph)
+    const component = graph.createNode('COMPONENT', page, {
+      layoutMode: 'VERTICAL',
+      primaryAxisSizing: 'FIXED',
+      counterAxisSizing: 'FIXED',
+      width: 100,
+      height: 100,
+      counterAxisAlign: 'STRETCH',
+      paddingLeft: 10,
+      paddingRight: 10
+    })
+    rect(graph, component.id, 80, 20, { layoutAlignSelf: 'STRETCH' })
+    const outer = autoFrame(graph, page, { width: 300, height: 150 })
+    const instance = graph.createInstance(component.id, outer.id, { width: 200, height: 100 })
+    if (!instance) throw new Error('Expected instance creation to succeed')
+    const instanceChild = graph.getChildren(instance.id)[0]
+
+    computeAllLayouts(graph, page)
+
+    const childNode = getNodeOrThrow(graph, instanceChild.id)
+    expect(childNode.x).toBe(10)
+    expect(childNode.width).toBe(180)
+  })
 })