Some random code to inspect the selection in the computed view

_devtools_computed_selection.js

let win = this.styleWindow;
let selection = win.getSelection();
let computedViewRanges = [];
for (let i = 0; i < selection.rangeCount; i++) {
  let range = selection.getRangeAt(i);
  if (!range.collapsed) {
    let ancestor = range.commonAncestorContainer;
    if (this.element == ancestor || this.element.contains(ancestor)) {
      console.log("valid range", range);
      computedViewRanges.push(range);
    }
  }
}

computedViewRanges.forEach(r => {
  console.log(r.toString());
});