diff --git a/tests/e2e/context-menu/basic.spec.ts b/tests/e2e/context-menu/basic.spec.ts
index c83a3b93b..30dc1af27 100644
--- a/tests/e2e/context-menu/basic.spec.ts
+++ b/tests/e2e/context-menu/basic.spec.ts
@@ -1,5 +1,6 @@
 import { expect, test, type Page } from '@playwright/test'
 
+import { expectDefined } from '#tests/helpers/assert'
 import { CanvasHelper } from '#tests/helpers/canvas'
 
 let page: Page
@@ -33,12 +34,16 @@ function getPageChildren() {
 }
 
 function getSelectedCount() {
-  return page.evaluate(() => window.__OPEN_PENCIL_STORE__!.state.selectedIds.size)
+  return page.evaluate(() => {
+    const store = window.__OPEN_PENCIL_STORE__
+    if (!store) throw new Error('OpenPencil store not initialized')
+    return store.state.selectedIds.size
+  })
 }
 
 async function rightClickShape(x: number, y: number) {
-  const box = await canvas.canvas.boundingBox()
-  await page.mouse.click(box!.x + x, box!.y + y, { button: 'right' })
+  const box = expectDefined(await canvas.canvas.boundingBox(), 'canvas bounds')
+  await page.mouse.click(box.x + x, box.y + y, { button: 'right' })
 }
 
 function contextMenu() {
@@ -104,17 +109,23 @@ test('toggle visibility via context menu', async () => {
   await canvas.click(250, 230)
   await canvas.waitForRender()
 
-  const nodeId = await page.evaluate(() => [...window.__OPEN_PENCIL_STORE__!.state.selectedIds][0])
+  const nodeId = await page.evaluate(() => {
+    const store = window.__OPEN_PENCIL_STORE__
+    if (!store) throw new Error('OpenPencil store not initialized')
+    return [...store.state.selectedIds][0]
+  })
 
   await rightClickShape(250, 230)
   await contextItem('context-toggle-visibility').click()
   await canvas.waitForRender()
 
   const hidden = await page.evaluate((id) => {
-    const n = window.__OPEN_PENCIL_STORE__!.graph.getNode(id)
+    const store = window.__OPEN_PENCIL_STORE__
+    if (!store) throw new Error('OpenPencil store not initialized')
+    const n = store.graph.getNode(id)
     return n ? { visible: n.visible } : null
   }, nodeId)
-  expect(hidden!.visible).toBe(false)
+  expect(hidden?.visible).toBe(false)
 
   // Toggle back: select via store since invisible nodes can't be hit-tested
   await page.evaluate(() => {
@@ -125,10 +136,12 @@ test('toggle visibility via context menu', async () => {
   await canvas.waitForRender()
 
   const restored = await page.evaluate((id) => {
-    const n = window.__OPEN_PENCIL_STORE__!.graph.getNode(id)
+    const store = window.__OPEN_PENCIL_STORE__
+    if (!store) throw new Error('OpenPencil store not initialized')
+    const n = store.graph.getNode(id)
     return n ? { visible: n.visible } : null
   }, nodeId)
-  expect(restored!.visible).toBe(true)
+  expect(restored?.visible).toBe(true)
 })
 
 test('toggle lock via context menu', async () => {
diff --git a/tests/e2e/panels/basic.spec.ts b/tests/e2e/panels/basic.spec.ts
index aa01b36a3..f6deb7443 100644
--- a/tests/e2e/panels/basic.spec.ts
+++ b/tests/e2e/panels/basic.spec.ts
@@ -1,5 +1,6 @@
 import { test, expect, type Page } from '@playwright/test'
 
+import { expectDefined } from '#tests/helpers/assert'
 import { CanvasHelper } from '#tests/helpers/canvas'
 
 let page: Page
@@ -27,8 +28,10 @@ test('layers panel resize increases width', async () => {
   const handleBox = await handle.boundingBox()
   expect(handleBox).not.toBeNull()
 
-  const cx = handleBox!.x + handleBox!.width / 2
-  const cy = handleBox!.y + handleBox!.height / 2
+  const handleBounds = expectDefined(handleBox, 'splitter handle bounds')
+  const beforeBounds = expectDefined(before, 'layers panel bounds')
+  const cx = handleBounds.x + handleBounds.width / 2
+  const cy = handleBounds.y + handleBounds.height / 2
 
   await page.mouse.move(cx, cy)
   await page.mouse.down()
@@ -36,22 +39,28 @@ test('layers panel resize increases width', async () => {
   await page.mouse.up()
   await canvas.waitForRender()
 
-  const after = await panel.boundingBox()
-  expect(after!.width).toBeGreaterThan(before!.width + 40)
+  const after = expectDefined(await panel.boundingBox(), 'resized layers panel bounds')
+  expect(after.width).toBeGreaterThan(beforeBounds.width + 40)
   canvas.assertNoErrors()
 })
 
 test('panel width persists after page reload', async () => {
   // Allow Reka's auto-save debounce to flush before recording the width
   await page.waitForTimeout(300)
-  const recordedWidth = (await page.locator('[data-test-id="layers-panel"]').boundingBox())!.width
+  const recordedWidth = expectDefined(
+    await page.locator('[data-test-id="layers-panel"]').boundingBox(),
+    'persisted layers panel bounds'
+  ).width
 
   await page.reload()
   canvas = new CanvasHelper(page)
   await canvas.waitForInit()
 
-  const after = await page.locator('[data-test-id="layers-panel"]').boundingBox()
-  expect(Math.abs(after!.width - recordedWidth)).toBeLessThanOrEqual(2)
+  const after = expectDefined(
+    await page.locator('[data-test-id="layers-panel"]').boundingBox(),
+    'reloaded layers panel bounds'
+  )
+  expect(Math.abs(after.width - recordedWidth)).toBeLessThanOrEqual(2)
   canvas.assertNoErrors()
 })
 
diff --git a/tests/e2e/perf/basic.spec.ts b/tests/e2e/perf/basic.spec.ts
index c13f0a866..a5b901423 100644
--- a/tests/e2e/perf/basic.spec.ts
+++ b/tests/e2e/perf/basic.spec.ts
@@ -37,9 +37,9 @@ test.describe('Render performance', () => {
             {
               type: 'SOLID',
               color: {
-                r: arr[i * 3]! / 255,
-                g: arr[i * 3 + 1]! / 255,
-                b: arr[i * 3 + 2]! / 255,
+                r: (arr[i * 3] ?? 0) / 255,
+                g: (arr[i * 3 + 1] ?? 0) / 255,
+                b: (arr[i * 3 + 2] ?? 0) / 255,
                 a: 1
               },
               visible: true,
@@ -89,7 +89,8 @@ test.describe('Render performance', () => {
     const results = await helper.page.evaluate((iterations: number) => {
       const store = window.__OPEN_PENCIL_STORE__
       if (!store) throw new Error('OpenPencil store not initialized')
-      const renderer = store.renderer!
+      const renderer = store.renderer
+      if (!renderer) throw new Error('OpenPencil renderer not initialized')
 
       function setupRenderer() {
         renderer.dpr = window.devicePixelRatio || 1
@@ -119,11 +120,15 @@ test.describe('Render performance', () => {
       const panMs = performance.now() - panStart
 
       // Benchmark 2: Scene change (cache miss every frame)
-      const nodes = [...store.graph.getNode(store.state.currentPageId)!.childIds]
+      const pageNode = store.graph.getNode(store.state.currentPageId)
+      if (!pageNode) throw new Error(`Page ${store.state.currentPageId} not found`)
+      const nodes = [...pageNode.childIds]
       setupRenderer()
       const sceneStart = performance.now()
       for (let i = 0; i < iterations; i++) {
-        const node = store.graph.getNode(nodes[i % nodes.length]!)
+        const nodeId = nodes[i % nodes.length]
+        if (!nodeId) throw new Error('Benchmark node id not found')
+        const node = store.graph.getNode(nodeId)
         if (node) store.graph.updateNode(node.id, { x: node.x + 0.1 })
         store.state.sceneVersion++
         renderer.render(store.graph, store.state.selectedIds, {}, store.state.sceneVersion)
@@ -177,7 +182,8 @@ test.describe('Render performance', () => {
       ({ count, iterations }) => {
         const store = window.__OPEN_PENCIL_STORE__
         if (!store) throw new Error('OpenPencil store not initialized')
-        const renderer = store.renderer!
+        const renderer = store.renderer
+        if (!renderer) throw new Error('OpenPencil renderer not initialized')
         const graph = store.graph
         const pageId = store.state.currentPageId
 
@@ -225,7 +231,9 @@ test.describe('Render performance', () => {
         setupRenderer()
         const sceneStart = performance.now()
         for (let i = 0; i < iterations; i++) {
-          const node = graph.getNode(shadowIds[i % shadowIds.length]!)
+          const nodeId = shadowIds[i % shadowIds.length]
+          if (!nodeId) throw new Error('Shadow benchmark node id not found')
+          const node = graph.getNode(nodeId)
           if (node) graph.updateNode(node.id, { x: node.x + 0.1 })
           store.state.sceneVersion++
           renderer.render(graph, store.state.selectedIds, {}, store.state.sceneVersion)
diff --git a/tests/e2e/properties/panel.spec.ts b/tests/e2e/properties/panel.spec.ts
index 154bb64b7..daa43773b 100644
--- a/tests/e2e/properties/panel.spec.ts
+++ b/tests/e2e/properties/panel.spec.ts
@@ -1,5 +1,6 @@
 import { expect, test, type Page } from '@playwright/test'
 
+import { expectDefined } from '#tests/helpers/assert'
 import { CanvasHelper } from '#tests/helpers/canvas'
 import { getPageChildren, getSelectedNode } from '#tests/helpers/store'
 
@@ -23,8 +24,7 @@ test('ScrubInput drag changes X position', async () => {
   await canvas.clearCanvas()
   await canvas.drawRect(100, 100, 80, 80)
   const before = await getSelectedNode(page)
-  expect(before).not.toBeNull()
-  const initialX = before!.x
+  const initialX = expectDefined(before, 'selected rectangle before drag').x
 
   const xScrub = page
     .locator('[data-test-id="position-section"] [data-test-id="scrub-input"]')
@@ -32,7 +32,7 @@ test('ScrubInput drag changes X position', async () => {
   await canvas.dragScrubInput(xScrub, 50)
 
   const after = await getSelectedNode(page)
-  expect(after!.x).not.toBe(initialX)
+  expect(after?.x).not.toBe(initialX)
   canvas.assertNoErrors()
 })
 
@@ -51,7 +51,7 @@ test('corner radius uniform sets cornerRadius', async () => {
   await canvas.waitForRender()
 
   const node = await getSelectedNode(page)
-  expect(node!.cornerRadius).toBe(12)
+  expect(node?.cornerRadius).toBe(12)
   canvas.assertNoErrors()
 })
 
@@ -86,8 +86,8 @@ test('fill gradient switch changes fill type', async () => {
   await page.locator('[data-test-id="fill-picker-tab-gradient"]').click()
   await canvas.waitForRender()
 
-  const node = await getSelectedNode(page)
-  expect(node!.fills[0].type).toBe('GRADIENT_LINEAR')
+  const node = expectDefined(await getSelectedNode(page), 'gradient-filled node')
+  expect(node.fills[0]?.type).toBe('GRADIENT_LINEAR')
   canvas.assertNoErrors()
 })
 
@@ -246,7 +246,7 @@ test('flip horizontal sets flipX', async () => {
   await canvas.waitForRender()
 
   const node = await getSelectedNode(page)
-  expect(node!.flipX).toBe(true)
+  expect(node?.flipX).toBe(true)
   canvas.assertNoErrors()
 })
 
@@ -260,13 +260,13 @@ test('clip content checkbox toggles clipsContent', async () => {
   await canvas.pressKey('Shift+a')
   await canvas.waitForRender()
 
-  const before = await getSelectedNode(page)
-  const initialValue = before!.clipsContent
+  const before = expectDefined(await getSelectedNode(page), 'selected frame before clipping')
+  const initialValue = before.clipsContent
 
   await page.locator('[data-test-id="clip-content-checkbox"]').click()
   await canvas.waitForRender()
 
   const after = await getSelectedNode(page)
-  expect(after!.clipsContent).toBe(!initialValue)
+  expect(after?.clipsContent).toBe(!initialValue)
   canvas.assertNoErrors()
 })
diff --git a/tests/engine/editor/undo/create-shape.test.ts b/tests/engine/editor/undo/create-shape.test.ts
index 481b708ca..9d3e266d7 100644
--- a/tests/engine/editor/undo/create-shape.test.ts
+++ b/tests/engine/editor/undo/create-shape.test.ts
@@ -2,6 +2,8 @@ import { describe, test, expect } from 'bun:test'
 
 import { createEditor } from '@open-pencil/core/editor'
 
+import { getNodeOrThrow } from '#tests/helpers/assert'
+
 describe('create shape undo/redo', () => {
   test('batched create+resize undoes in one step', () => {
     const editor = createEditor()
@@ -13,8 +15,8 @@ describe('create shape undo/redo', () => {
     editor.commitResize(id, { x: 100, y: 100, width: 0, height: 0 })
     editor.undo.commitBatch()
 
-    expect(editor.graph.getNode(id)!.width).toBe(200)
-    expect(editor.graph.getNode(id)!.height).toBe(150)
+    expect(getNodeOrThrow(editor.graph, id).width).toBe(200)
+    expect(getNodeOrThrow(editor.graph, id).height).toBe(150)
 
     // Single undo removes the shape entirely
     editor.undo.undo()
@@ -22,11 +24,11 @@ describe('create shape undo/redo', () => {
 
     // Single redo restores with full dimensions
     editor.undo.redo()
-    expect(editor.graph.getNode(id)).not.toBeUndefined()
-    expect(editor.graph.getNode(id)!.width).toBe(200)
-    expect(editor.graph.getNode(id)!.height).toBe(150)
-    expect(editor.graph.getNode(id)!.x).toBe(100)
-    expect(editor.graph.getNode(id)!.y).toBe(100)
+    const restored = getNodeOrThrow(editor.graph, id)
+    expect(restored.width).toBe(200)
+    expect(restored.height).toBe(150)
+    expect(restored.x).toBe(100)
+    expect(restored.y).toBe(100)
   })
 
   test('redo after create+move+duplicate restores correct state', () => {
@@ -46,7 +48,7 @@ describe('create shape undo/redo', () => {
 
     // Undo move
     editor.undo.undo()
-    expect(editor.graph.getNode(id)!.x).toBe(50)
+    expect(getNodeOrThrow(editor.graph, id).x).toBe(50)
 
     // Undo create (single step)
     editor.undo.undo()
@@ -54,10 +56,10 @@ describe('create shape undo/redo', () => {
 
     // Redo create (single step, full dimensions)
     editor.undo.redo()
-    expect(editor.graph.getNode(id)!.width).toBe(120)
+    expect(getNodeOrThrow(editor.graph, id).width).toBe(120)
 
     // Redo move
     editor.undo.redo()
-    expect(editor.graph.getNode(id)!.x).toBe(200)
+    expect(getNodeOrThrow(editor.graph, id).x).toBe(200)
   })
 })
diff --git a/tests/engine/mcp.test.ts b/tests/engine/mcp.test.ts
index e5b847270..9cb5b3adb 100644
--- a/tests/engine/mcp.test.ts
+++ b/tests/engine/mcp.test.ts
@@ -2,6 +2,8 @@ import { describe, expect, test } from 'bun:test'
 
 import { ALL_TOOLS, FigmaAPI, SceneGraph, computeAllLayouts, parseFigFile } from '@open-pencil/core'
 
+import { expectDefined } from '#tests/helpers/assert'
+
 describe('MCP tool execution', () => {
   function setup() {
     const graph = new SceneGraph()
@@ -59,12 +61,11 @@ describe('MCP tool execution', () => {
     expect(result.type).toBe('FRAME')
     expect(result.name).toBe('TestFrame')
 
-    const node = api.getNodeById(result.id)
-    expect(node).not.toBeNull()
-    expect(node!.x).toBe(10)
-    expect(node!.y).toBe(20)
-    expect(node!.width).toBe(300)
-    expect(node!.height).toBe(200)
+    const node = expectDefined(api.getNodeById(result.id), 'created frame')
+    expect(node.x).toBe(10)
+    expect(node.y).toBe(20)
+    expect(node.width).toBe(300)
+    expect(node.height).toBe(200)
   })
 
   test('set_fill applies color', () => {
@@ -78,7 +79,7 @@ describe('MCP tool execution', () => {
     }) as { id: string }
 
     findTool('set_fill').execute(api, { id: frame.id, color: '#ff0000' })
-    const node = api.getNodeById(frame.id)!
+    const node = expectDefined(api.getNodeById(frame.id), 'filled rectangle')
     expect(node.fills).toHaveLength(1)
     expect(node.fills[0].color.r).toBeCloseTo(1)
     expect(node.fills[0].color.g).toBeCloseTo(0)
@@ -102,7 +103,7 @@ describe('MCP tool execution', () => {
       padding: 24
     })
 
-    const node = api.getNodeById(frame.id)!
+    const node = expectDefined(api.getNodeById(frame.id), 'layout frame')
     expect(node.layoutMode).toBe('VERTICAL')
     expect(node.itemSpacing).toBe(16)
     expect(node.paddingTop).toBe(24)
@@ -133,9 +134,11 @@ describe('MCP tool execution', () => {
     const tree = findTool('get_page_tree').execute(api, {}) as {
       children: { id: string; children?: unknown[] }[]
     }
-    const parentNode = tree.children.find((c: { id: string }) => c.id === parent.id)
-    expect(parentNode).toBeDefined()
-    expect(parentNode!.children).toBeArray()
+    const parentNode = expectDefined(
+      tree.children.find((c: { id: string }) => c.id === parent.id),
+      'parent tree node'
+    )
+    expect(parentNode.children).toBeArray()
   })
 
   test('delete_node removes node', () => {
@@ -195,7 +198,7 @@ describe('MCP tool execution', () => {
 
     const clone = findTool('clone_node').execute(api, { id: frame.id }) as { id: string }
     expect(clone.id).not.toBe(frame.id)
-    const clonedNode = api.getNodeById(clone.id)!
+    const clonedNode = expectDefined(api.getNodeById(clone.id), 'cloned node')
     expect(clonedNode.width).toBe(100)
     expect(clonedNode.height).toBe(50)
   })
@@ -224,7 +227,7 @@ describe('MCP tool execution', () => {
     expect(result.updated).toContain('cornerRadius')
     expect(result.updated).toContain('name')
 
-    const node = api.getNodeById(frame.id)!
+    const node = expectDefined(api.getNodeById(frame.id), 'updated node')
     expect(node.x).toBe(50)
     expect(node.opacity).toBe(0.5)
     expect(node.cornerRadius).toBe(8)
diff --git a/tests/engine/scene-graph/instance-overrides.test.ts b/tests/engine/scene-graph/instance-overrides.test.ts
index 0ded9bff0..b2f9dd899 100644
--- a/tests/engine/scene-graph/instance-overrides.test.ts
+++ b/tests/engine/scene-graph/instance-overrides.test.ts
@@ -2,6 +2,8 @@ import { describe, test, expect } from 'bun:test'
 
 import { importNodeChanges, type NodeChange } from '@open-pencil/core'
 
+import { expectDefined } from '#tests/helpers/assert'
+
 const ID = { m00: 1, m01: 0, m02: 0, m10: 0, m11: 1, m12: 0 }
 const SIZE = { x: 100, y: 100 }
 
@@ -85,7 +87,10 @@ function swapOverrideFixture(opts?: { customName?: string }): NodeChange[] {
 describe('instance swap overrides', () => {
   test('swap override renames icon and reclones children', () => {
     const graph = importNodeChanges(swapOverrideFixture())
-    const page = graph.getPages().find((p) => p.name === 'Page1')!
+    const page = expectDefined(
+      graph.getPages().find((p) => p.name === 'Page1'),
+      'Page1'
+    )
     const button = graph.getChildren(page.id)[0]
     expect(button.name).toBe('ButtonInstance')
 
@@ -100,7 +105,10 @@ describe('instance swap overrides', () => {
 
   test('swap override preserves user-given name', () => {
     const graph = importNodeChanges(swapOverrideFixture({ customName: 'MyCustomIcon' }))
-    const page = graph.getPages().find((p) => p.name === 'Page1')!
+    const page = expectDefined(
+      graph.getPages().find((p) => p.name === 'Page1'),
+      'Page1'
+    )
     const button = graph.getChildren(page.id)[0]
     const icon = graph.getChildren(button.id)[0]
 
@@ -138,11 +146,16 @@ describe('instance swap overrides', () => {
     ]
 
     const graph = importNodeChanges(nodes)
-    const page = graph.getPages().find((p) => p.name === 'Page1')!
+    const page = expectDefined(
+      graph.getPages().find((p) => p.name === 'Page1'),
+      'Page1'
+    )
     const children = graph.getChildren(page.id)
 
-    const wrapper = children.find((c) => c.name === 'WrapperInstance')!
-    expect(wrapper).toBeDefined()
+    const wrapper = expectDefined(
+      children.find((c) => c.name === 'WrapperInstance'),
+      'wrapper instance'
+    )
 
     // WrapperInstance > ButtonInstance > icon
     const wrapperButton = graph.getChildren(wrapper.id)[0]
@@ -168,14 +181,23 @@ describe('instance swap overrides', () => {
     ]
 
     const graph = importNodeChanges(nodes)
-    const page = graph.getPages().find((p) => p.name === 'Page1')!
+    const page = expectDefined(
+      graph.getPages().find((p) => p.name === 'Page1'),
+      'Page1'
+    )
     const children = graph.getChildren(page.id)
 
-    const swapped = children.find((c) => c.name === 'ButtonInstance')!
+    const swapped = expectDefined(
+      children.find((c) => c.name === 'ButtonInstance'),
+      'swapped button instance'
+    )
     const swappedIcon = graph.getChildren(swapped.id)[0]
     expect(swappedIcon.name).toBe('IconB')
 
-    const defaultBtn = children.find((c) => c.name === 'ButtonDefault')!
+    const defaultBtn = expectDefined(
+      children.find((c) => c.name === 'ButtonDefault'),
+      'default button instance'
+    )
     const defaultIcon = graph.getChildren(defaultBtn.id)[0]
     expect(defaultIcon.name).toBe('IconA')
   })
@@ -226,7 +248,10 @@ describe('instance swap overrides', () => {
     ]
 
     const graph = importNodeChanges(nodes)
-    const page = graph.getPages().find((p) => p.name === 'Page1')!
+    const page = expectDefined(
+      graph.getPages().find((p) => p.name === 'Page1'),
+      'Page1'
+    )
     const container = graph.getChildren(page.id)[0]
 
     // ContainerInstance > ButtonSwapped > icon
diff --git a/tests/engine/svg/import.test.ts b/tests/engine/svg/import.test.ts
index 69496eafc..434348378 100644
--- a/tests/engine/svg/import.test.ts
+++ b/tests/engine/svg/import.test.ts
@@ -3,6 +3,8 @@ import { describe, test, expect, beforeEach } from 'bun:test'
 import { FigmaAPI, SceneGraph } from '@open-pencil/core'
 import { importSvg } from '@open-pencil/core/tools'
 
+import { expectDefined, getNodeOrThrow } from '#tests/helpers/assert'
+
 let graph: SceneGraph
 let figma: FigmaAPI
 
@@ -20,16 +22,17 @@ describe('import_svg', () => {
     expect(result.id).toBeDefined()
     expect(result.type).toBe('FRAME')
 
-    const frame = graph.getNode(result.id)
-    expect(frame).not.toBeUndefined()
-    expect(frame!.width).toBe(24)
-    expect(frame!.height).toBe(24)
+    const frame = getNodeOrThrow(graph, result.id)
+    expect(frame.width).toBe(24)
+    expect(frame.height).toBe(24)
 
     const children = graph.getChildren(result.id)
     expect(children.length).toBe(1)
     expect(children[0].type).toBe('VECTOR')
     expect(children[0].vectorNetwork).toBeDefined()
-    expect(children[0].vectorNetwork!.vertices.length).toBeGreaterThan(0)
+    expect(
+      expectDefined(children[0].vectorNetwork, 'imported vector network').vertices.length
+    ).toBeGreaterThan(0)
   })
 
   test('imports multiple shapes', async () => {
@@ -51,9 +54,9 @@ describe('import_svg', () => {
       svg: '<svg viewBox="0 0 200 100"><path d="M0 0 L200 100"/></svg>'
     })) as { id: string }
 
-    const frame = graph.getNode(result.id)
-    expect(frame!.width).toBe(200)
-    expect(frame!.height).toBe(100)
+    const frame = getNodeOrThrow(graph, result.id)
+    expect(frame.width).toBe(200)
+    expect(frame.height).toBe(100)
   })
 
   test('uses width/height attributes when no viewBox', async () => {
@@ -61,9 +64,9 @@ describe('import_svg', () => {
       svg: '<svg width="48" height="48"><path d="M0 0 L48 48"/></svg>'
     })) as { id: string }
 
-    const frame = graph.getNode(result.id)
-    expect(frame!.width).toBe(48)
-    expect(frame!.height).toBe(48)
+    const frame = getNodeOrThrow(graph, result.id)
+    expect(frame.width).toBe(48)
+    expect(frame.height).toBe(48)
   })
 
   test('sets custom name', async () => {
@@ -116,9 +119,9 @@ describe('import_svg', () => {
       y: 200
     })) as { id: string }
 
-    const frame = graph.getNode(result.id)
-    expect(frame!.x).toBe(100)
-    expect(frame!.y).toBe(200)
+    const frame = getNodeOrThrow(graph, result.id)
+    expect(frame.x).toBe(100)
+    expect(frame.y).toBe(200)
   })
 
   test('returns error for empty SVG', async () => {