How to use the element-ui/src/utils/dom.hasClass function in element-ui

handleCellMouseEnter(event, row) {
      const table = this.table;
      const cell = getCell(event);

      if (cell) {
        const column = getColumnByCell(table, cell);
        const hoverState = table.hoverState = {cell, column, row};
        table.$emit('cell-mouse-enter', hoverState.row, hoverState.column, hoverState.cell, event);
      }

      // 判断是否text-overflow, 如果是就显示tooltip
      const cellChild = event.target.querySelector('.cell');

      if (hasClass(cellChild, 'el-tooltip') && cellChild.scrollWidth > cellChild.offsetWidth && this.$refs.tooltip) {
        const tooltip = this.$refs.tooltip;

        this.tooltipContent = cell.textContent || cell.innerText;
        tooltip.referenceElm = cell;
        tooltip.$refs.popper && (tooltip.$refs.popper.style.display = 'none');
        tooltip.doDestroy();
        tooltip.setExpectedState(true);
        this.activateTooltip(tooltip);
      }
    },

handleCellMouseEnter(event, row) {
      const table = this.table;
      const cell = getCell(event);

      if (cell) {
        const column = getColumnByCell(table, cell);
        const hoverState = table.hoverState = {cell, column, row};
        table.$emit('cell-mouse-enter', hoverState.row, hoverState.column, hoverState.cell, event);
      }

      // 判断是否text-overflow, 如果是就显示tooltip
      const cellChild = event.target.querySelector('.cell');

      if (hasClass(cellChild, 'el-tooltip') && cellChild.scrollWidth > cellChild.offsetWidth) {
        const tooltip = this.$refs.tooltip;

        this.tooltipContent = cell.innerText;
        tooltip.referenceElm = cell;
        tooltip.$refs.popper && (tooltip.$refs.popper.style.display = 'none');
        tooltip.doDestroy();
        tooltip.setExpectedState(true);
        this.activateTooltip(tooltip);
      }
    },

handleCellMouseEnter(event, row) {
      const table = this.table;
      const cell = getCell(event);

      if (cell) {
        const column = getColumnByCell(table, cell);
        const hoverState = table.hoverState = {cell, column, row};
        table.$emit('cell-mouse-enter', hoverState.row, hoverState.column, hoverState.cell, event);
      }

      // 判断是否text-overflow, 如果是就显示tooltip
      const cellChild = event.target.querySelector('.cell');
      if (!(hasClass(cellChild, 'el-tooltip') && cellChild.childNodes.length)) {
        return;
      }
      // use range width instead of scrollWidth to determine whether the text is overflowing
      // to address a potential FireFox bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1074543#c3
      const range = document.createRange();
      range.setStart(cellChild, 0);
      range.setEnd(cellChild, cellChild.childNodes.length);
      const rangeWidth = range.getBoundingClientRect().width;
      const padding = (parseInt(getStyle(cellChild, 'paddingLeft'), 10) || 0) +
        (parseInt(getStyle(cellChild, 'paddingRight'), 10) || 0);
      if ((rangeWidth + padding > cellChild.offsetWidth || cellChild.scrollWidth > cellChild.offsetWidth) && this.$refs.tooltip) {
        const tooltip = this.$refs.tooltip;
        // TODO 会引起整个 Table 的重新渲染，需要优化
        this.tooltipContent = cell.innerText || cell.textContent;
        tooltip.referenceElm = cell;
        tooltip.$refs.popper && (tooltip.$refs.popper.style.display = 'none');

setCurrentValue(value, event) {
        if (this.rateDisabled) {
          return;
        }
        /* istanbul ignore if */
        if (this.allowHalf) {
          let target = event.target;
          if (hasClass(target, 'el-rate__item')) {
            target = target.querySelector('.el-rate__icon');
          }
          if (hasClass(target, 'el-rate__decimal')) {
            target = target.parentNode;
          }
          this.pointerAtLeftHalf = event.offsetX * 2 <= target.clientWidth;
          this.currentValue = this.pointerAtLeftHalf ? value - 0.5 : value;
        } else {
          this.currentValue = value;
        }
        this.hoverIndex = value;
      },

      const rows = [].filter.call(tr, row => hasClass(row, 'el-table__row'));
      const oldRow = rows[data.indexOf(oldVal)];

handleFilterClick(event, column) {
      event.stopPropagation();
      const target = event.target;
      let cell = target.tagName === 'TH' ? target : target.parentNode;
      if (hasClass(cell, 'noclick')) return;
      cell = cell.querySelector('.el-table__column-filter-trigger') || cell;
      const table = this.$parent;

      let filterPanel = this.filterPanels[column.id];

      if (filterPanel && column.filterOpened) {
        filterPanel.showPopper = false;
        return;
      }

      if (!filterPanel) {
        filterPanel = new Vue(FilterPanel);
        this.filterPanels[column.id] = filterPanel;
        if (column.filterPlacement) {
          filterPanel.placement = column.filterPlacement;
        }

handleSortClick(event, column, givenOrder) {
      event.stopPropagation();
      let order = column.order === givenOrder ? null : givenOrder || this.toggleOrder(column);

      let target = event.target;
      while (target && target.tagName !== "TH") {
        target = target.parentNode;
      }

      if (target && target.tagName === "TH") {
        if (hasClass(target, "noclick")) {
          removeClass(target, "noclick");
          return;
        }
      }

      if (!column.sortable) return;

      const states = this.store.states;
      let sortProp = states.sortProp;
      let sortOrder;
      const sortingColumn = states.sortingColumn;

      if (sortingColumn !== column || (sortingColumn === column && sortingColumn.order === null)) {
        if (sortingColumn) {
          sortingColumn.order = null;
        }

if (!column || !column.resizable) return;

      if (!this.dragging && this.border) {
        let rect = target.getBoundingClientRect();

        const bodyStyle = document.body.style;
        if (rect.width > 12 && rect.right - event.pageX < 8) {
          bodyStyle.cursor = 'col-resize';
          if (hasClass(target, 'is-sortable')) {
            target.style.cursor = 'col-resize';
          }
          this.draggingColumn = column;
        } else if (!this.dragging) {
          bodyStyle.cursor = '';
          if (hasClass(target, 'is-sortable')) {
            target.style.cursor = 'pointer';
          }
          this.draggingColumn = null;
        }
      }
    },

handleSortClick (event, column, givenOrder) {
      event.stopPropagation();
      let order = givenOrder || this.toggleOrder(column.order);

      let target = event.target;
      while (target && target.tagName !== 'TH') {
        target = target.parentNode;
      }

      if (target && target.tagName === 'TH') {
        if (hasClass(target, 'noclick')) {
          removeClass(target, 'noclick');
          return;
        }
      }

      if (!column.sortable) return;

      const states = this.store.states;
      let sortProp = states.sortProp;
      let sortOrder;
      const sortingColumn = states.sortingColumn;

      if (sortingColumn !== column || (sortingColumn === column && sortingColumn.order === null)) {
        if (sortingColumn) {
          sortingColumn.order = null;
        }

if (!column || !column.resizable) return;

      if (!this.dragging && this.border) {
        let rect = target.getBoundingClientRect();

        const bodyStyle = document.body.style;
        if (rect.width > 12 && rect.right - event.pageX < 8) {
          bodyStyle.cursor = 'col-resize';
          if (hasClass(target, 'is-sortable')) {
            target.style.cursor = 'col-resize';
          }
          this.draggingColumn = column;
        } else if (!this.dragging) {
          bodyStyle.cursor = '';
          if (hasClass(target, 'is-sortable')) {
            target.style.cursor = 'pointer';
          }
          this.draggingColumn = null;
        }
      }
    },