添加 rich-text.test 示例，测试动态修改内容组件高度是否正确

(cherry picked from commit 67a9abbc)

pages/component/rich-text/rich-text.test.js

+const PAGE_PATH = '/pages/component/rich-text/rich-text'
+
+describe('rich-text-test', () => {
+
+  // 先屏蔽 android 及 web 平台
+  if (process.env.uniTestPlatformInfo.startsWith('android') || process.env.uniTestPlatformInfo.startsWith('web')) {
+    it('other platform', () => {
+      expect(1).toBe(1)
+    })
+    return
+  }
+
+  let page
+  beforeAll(async () => {
+    page = await program.reLaunch(PAGE_PATH)
+    await page.waitFor(1000);
+  })
+
+
+  it('richt-text-height', async () => {
+    let beforeValue = await page.data('richTextHeight')
+    await page.callMethod('changeText')
+    await page.waitFor(500)
+    await page.callMethod('changeText')
+    await page.waitFor(500)
+    let afterValue = await page.data('richTextHeight')
+    console.log('beforeValue:', beforeValue)
+    console.log('afterValue:', afterValue)
+    expect(beforeValue).toBe(afterValue)
+  })
+
+})

pages/component/rich-text/rich-text.uvue

@@ -16,14 +16,48 @@
         <text class="uni-subtitle-text">selectable</text>
       </view>
       <view class="text-box">
-        <rich-text :selectable="true"
-          nodes="<span>hello uni-app x!</span><br/><span>uni-app x，终极跨平台方案</span>"></rich-text>
+        <rich-text id="richtext" @click="changeText" style="border: 1px; border-style: solid; border-color: red;" :selectable="true"
+          :nodes="text"></rich-text>
       </view>
     </view>
   </view>
 </template>
 
 <script>
+  export default {
+    data() {
+      return {
+        text: "<span>hello uni-app x!</span><br/><span>uni-app x，终极跨平台方案</span>",
+        richTextHeight: 0,
+        richTextElement: null as UniElement | null
+      }
+    },
+    onReady() {
+      this.richTextElement = uni.getElementById('richtext') as UniElement
+      setTimeout(() => {
+        this.updateRichTextHeight()
+      }, 500)
+    },
+    methods: {
+      changeText() {
+        if (this.text === "<span>hello uni-app x!</span><br/><span>uni-app x，终极跨平台方案</span>") {
+          this.text = "<h1>hello uni-app x!</h1><br/><h2>uni-app x，终极跨平台方案</h2>"
+        } else {
+          this.text = "<span>hello uni-app x!</span><br/><span>uni-app x，终极跨平台方案</span>"
+        }
+        setTimeout(() => {
+          this.updateRichTextHeight()
+        }, 200)
+      },
+      updateRichTextHeight() {
+        if (this.richTextElement != null) {
+          const elRect = this.richTextElement!.getBoundingClientRect()
+          this.richTextHeight = elRect.height
+          console.log('richTextHeight:', this.richTextHeight)
+        }
+      }
+    }
+  }
 </script>
 
 <style>