<!doctype html>
<html>
<head>
<meta charset="utf-8">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
"use strict";

promise_test(async () => {
  await new Promise(resolve => document.addEventListener("DOMContentLoaded", resolve));

  getSelection().removeAllRanges();
  const range = document.createRange();
  range.setStart(document.querySelector("span"), 0);
  getSelection().addRange(range);
  getSelection().addRange(range);
  assert_equals(getSelection().rangeCount, 1, "Adding same collapsed range twice should not clone the range");
  assert_equals(getSelection().getRangeAt(0), range, "The first range should be the added range");
  assert_equals(getSelection().focusNode, document.querySelector("span"), "Focus node should be the <span>");
  assert_equals(getSelection().focusOffset, 0, "Focus offset should be 0");
  assert_true(getSelection().isCollapsed, "Selection should be collapsed");
}, "Adding same collapsed range should not change selections");

promise_test(async () => {
  getSelection().removeAllRanges();
  const range = document.createRange();
  range.selectNodeContents(document.querySelector("div"));
  getSelection().addRange(range);
  getSelection().addRange(range);
  assert_equals(getSelection().rangeCount, 1, "Adding same range twice should not clone the range");
  assert_equals(getSelection().getRangeAt(0), range, "The first range should be the added range");
  assert_equals(getSelection().anchorNode, document.querySelector("div"), "Anchor node should be the <div>");
  assert_equals(getSelection().anchorOffset, 0, "Anchor offset should be 0");
  assert_equals(getSelection().focusNode, document.querySelector("div"), "Focus node should be the <div>");
  assert_equals(getSelection().focusOffset, 1, "Focus offset should be 1");
}, "Adding non-collapsed range after updating the range should not change selections");

promise_test(async () => {
  getSelection().removeAllRanges();
  const range = document.createRange();
  range.collapse(document.querySelector("span"), 0);
  getSelection().addRange(range);
  range.selectNodeContents(document.querySelector("div"));
  getSelection().addRange(range);
  assert_equals(getSelection().rangeCount, 1, "Adding same range twice should not clone the range");
  assert_equals(getSelection().getRangeAt(0), range, "The first range should be the added range");
  assert_equals(getSelection().anchorNode, document.querySelector("div"), "Anchor node should be the <div>");
  assert_equals(getSelection().anchorOffset, 0, "Anchor offset should be 0");
  assert_equals(getSelection().focusNode, document.querySelector("div"), "Focus node should be the <div>");
  assert_equals(getSelection().focusOffset, 1, "Focus offset should be 1");
}, "Adding same collapsed range after updating the range should not change selections");
</script>
</head>
<body><div><span></span></div></body>
</html>
