⚡ perf(vscode): 代码阅读预览按卡片订阅状态：中文名、调用树棵数、单击高亮、问答一条消息只重画受影响的卡片和文字，新文档里内容没变的块沿用原来的对象不重画，没展开又没说过的块不画问答区

vscode/webview-ui/src/codeReader/occurrences.test.ts

@@ -46,6 +46,27 @@ describe('occurrences：哪些段画高亮', () => {
     expect(segmentOccurrence({ text: '\'./util\'', role: 'string', offset: 9 }, occurrences)).toBe('normal')
   })
 
+  it('出现很多、乱序、有长有短还互相重叠时，结果和逐处比一样', () => {
+    const brute = (segment: Segment, occurrences: readonly Occurrence[]): string | undefined => {
+      const hits = occurrences.filter(occurrence => occurrence.start < segment.offset! + segment.text.length && segment.offset! < occurrence.end)
+      return hits.length === 0 ? undefined : hits.some(hit => hit.kind === 'write') ? 'strong' : 'normal'
+    }
+    let seed = 7
+    const random = (n: number): number => {
+      seed = (seed * 1103515245 + 12345) % 2147483648
+      return seed % n
+    }
+    const kinds: Occurrence['kind'][] = ['read', 'write', 'text']
+    const occurrences = Array.from({ length: 300 }, () => {
+      const start = random(2000)
+      return at(start, start + 1 + random(12), kinds[random(3)])
+    })
+    for (let offset = 0; offset < 2020; offset += 3) {
+      const segment = name('x'.repeat(1 + (offset % 7)), offset)
+      expect(segmentOccurrence(segment, occurrences), `offset ${offset}`).toBe(brute(segment, occurrences))
+    }
+  })
+
   it('写入用强高亮色，读取和按文字认出的用普通高亮色；同一段碰上两种按写入画', () => {
     expect(occurrenceStyle('write')).toBe('strong')
     expect(occurrenceStyle('read')).toBe('normal')