后端返回数据：

sourceCode格式.png

matchLinesJson格式.png

前端需展示：

1、正常解析源码，每行增加行号
2、匹配的行高亮显示
3、初始化定位到第一次高亮的行
4、垂直滚动时，行数和对应的代码同时滚动；水平滚动时，只滚动右侧代码部分

效果图.png

实现代码：

<template>
  <div class="source-code" v-loading="isLoading">
    <pre ref="sourceCode">{{ sourceCode }}</pre>
    <div class="index">
      <div ref="index">
        <span v-for="item in list" :key="item.index">{{ item.index }}</span>
      </div>
    </div>
    <div class="content" ref="content">
      <div>
        <span :class="`code${item.index}`" v-for="item in list" :key="item.index"><i :class="{ isMark: item.isMark }">{{ item.content }}</i></span>
      </div>
    </div>
  </div>
</template>
<script>
import _ from 'lodash';
export default {
  name: 'pre-html',
  props: {
    sourceCode: { // 源码
      type: String,
      default: '',
    },
    matchLinesJson: { // 匹配上的行
      type: Array,
      default: () => [],
    },
    coverage: { // 匹配程度（0-100）
      type: Number,
      default: -1,
    }
  },
  data() {
    return {
      list: [],
      isLoading: true,
      firstMarkedLine: -1,
    }
  },
  mounted() {
    this.init();
    this.$refs.content.addEventListener('scroll', this.onScroll);
  },
  beforeDestroy() {
    this.$refs.content.removeEventListener('scroll', this.onScroll);
  },
  methods: {
    init() {
      const el = this.$refs.sourceCode;
      const content = el.textContent;
      // 13回车、10换行（经测试只用解析换行）
      const linesArray = content.split(String.fromCharCode(10));
      const matchLines = this.matchLinesJson.map(d => [d.startingMatchLine, d.endingMatchLine]);
      this.list = linesArray.map((d, i) => {
        const isMark = this.coverage === 100 ? true : matchLines.some(c => (i + 1) >= c[0] && (i + 1) <= c[1]);
        if (isMark && this.firstMarkedLine < 0) {
          this.firstMarkedLine = i + 1;
        }
        return {
          content: d,
          index: i + 1,
          isMark,
        };
      });
      this.isLoading = false;
      if (this.firstMarkedLine <= 1) return;
      this.$nextTick(() => {
        const cel = document.querySelector(`.code${this.firstMarkedLine}`);
        const pEl = this.$refs.content;
        if (!cel || !pEl) return;
        const t = cel.offsetTop - 10;
        if (t > 10) {
          pEl.scrollTop = t;
        }
      });
    },
    onScroll() {
      return _.throttle(() => {
        const st = (this.$refs.content && this.$refs.content.scrollTop) || 0;
        if (!this.$refs.index) return;
        this.$refs.index.style.marginTop = -st + 'px';
      }, 50)();
    },
  },
}
</script>

<style  lang="scss" scoped>

.source-code {
  max-height: 300px;
  overflow: hidden;
  display: flex;
  position: relative;
  pre {
    position: fixed;
    visibility: hidden;
  }
  .index {
    flex: none;
    overflow: hidden;
    > div {
      min-width: 30px;
      padding: 12px 8px;
      border-right: 1px solid #eee;
    }
    span {
      display: block;
      line-height: 20px;
      font-size: 12px;
      height: 20px;
      color: #999;
    }
  }
  .content {
    flex: 1;
    width: 0;
    overflow: auto;
    > div {
      padding: 12px 8px;
      width: 100%;
    }
    span {
      display: block;
      padding: 0 4px;
      white-space: pre;
      line-height: 20px;
      font-size: 12px;
      height: 20px;
      color: #333;
    }
    i {
      font-style: normal;
      min-width: 1px;
      height: 100%;
      display: inline-block;
      vertical-align: bottom;
      &.isMark {
        background: #FFE5D1;
      }
    }
  }
}
</style>