refactor(chart): enforce 400-line source limit

src/test/setup.ts

@@ -22,8 +22,8 @@ export class ResizeObserverMock {
     this.target = target
   })
 
-  unobserve = vi.fn()
-  disconnect = vi.fn()
+  unobserve: () => void = vi.fn()
+  disconnect: () => void = vi.fn()
 
   resize(width: number, height = 400) {
     if (!this.target) return

src/test/waveformChart.ts

@@ -0,0 +1,63 @@
+import { flushPromises, mount } from '@vue/test-utils'
+
+import WaveformChart from '../components/WaveformChart.vue'
+import type { WaveformData } from '../components/waveform'
+import { resizeObservers } from './setup'
+
+export async function mountSizedChart(data: WaveformData, extraProps = {}) {
+  const wrapper = mount(WaveformChart, {
+    props: { data, ...extraProps },
+  })
+  resizeObservers.at(-1)?.resize(800, 360)
+  await flushPromises()
+  return wrapper
+}
+
+export function gridSeries(count: number): WaveformData {
+  return {
+    kind: 'series',
+    series: Array.from({ length: count }, (_, index) => ({
+      id: `channel-${index}`,
+      name: `通道 ${index + 1}`,
+      data: {
+        kind: 'points',
+        points: [
+          { x: 0, y: index },
+          { x: 1, y: index + 1 },
+        ],
+      },
+    })),
+  }
+}
+
+export function visibilitySeries(): WaveformData {
+  return {
+    kind: 'series',
+    series: [
+      {
+        id: 'low',
+        trackId: 'shared-frame',
+        name: '低量程',
+        data: {
+          kind: 'points',
+          points: [
+            { x: 0, y: 0 },
+            { x: 1, y: 10 },
+          ],
+        },
+      },
+      {
+        id: 'high',
+        trackId: 'shared-frame',
+        name: '高量程',
+        data: {
+          kind: 'points',
+          points: [
+            { x: 10, y: 1000 },
+            { x: 20, y: 2000 },
+          ],
+        },
+      },
+    ],
+  }
+}