<!DOCTYPE html>
<meta charset="utf-8">
<title>Selection.modify() tests</title>
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>

<div>Test, these are <strong id="strong"> strong </strong> <em id="em"> italic </em> normal.</div>

<pre id="preLinefeed">
foo
bar
</pre>

<pre id="preBr">
foo<br>bar
</pre>

<pre id="preLinefeedBr">
foo
<br>
bar
</pre>

<script>
const selection = getSelection();
test(() => {
  selection.collapse(strong.childNodes[0], 4);
  selection.modify("extend", "backward", "word")
  assert_equals(selection.focusNode, strong.childNodes[0]);
  assert_equals(selection.focusOffset, 1);
  selection.collapse(em.childNodes[0], 4);
  selection.modify("extend", "backward", "word")
  assert_equals(selection.focusNode, em.childNodes[0]);
  assert_equals(selection.focusOffset, 1);
}, "Stop at previous word boundary when whitespaces are trimmed");

test(() => {
  const preLinefeed = document.getElementById("preLinefeed");
  const textChild = preLinefeed.childNodes[0];
  selection.collapse(textChild, 3);
  selection.modify("move", "forward", "character");
  assert_equals(selection.focusNode, textChild);
  assert_equals(selection.focusOffset, 4);
}, "Jump linefeed forward");

test(() => {
  const preLinefeed = document.getElementById("preLinefeed");
  const textChild = preLinefeed.childNodes[0];
  selection.collapse(textChild, 4);
  selection.modify("move", "backward", "character");
  assert_equals(selection.focusNode, textChild);
  assert_equals(selection.focusOffset, 3);
}, "Jump linefeed backward");

test(() => {
  const preBr = document.getElementById("preBr");
  const [firstTextChild, br, secondTextChild] = preBr.childNodes;
  selection.collapse(firstTextChild, 3);
  selection.modify("move", "forward", "character");
  assert_equals(selection.focusNode, secondTextChild);
  assert_equals(selection.focusOffset, 0);
}, "Jump <br> forward");

test(() => {
  const preBr = document.getElementById("preBr");
  const [firstTextChild, br, secondTextChild] = preBr.childNodes;
  selection.collapse(secondTextChild, 0);
  selection.modify("move", "backward", "character");
  assert_equals(selection.focusNode, firstTextChild);
  assert_equals(selection.focusOffset, 3);
}, "Jump <br> backward");

test(() => {
  const preLinefeedBr = document.getElementById("preLinefeedBr");
  selection.collapse(preLinefeedBr, 1);
  selection.modify("move", "forward", "character");
  const secondTextChild = preLinefeedBr.childNodes[2];
  assert_equals(selection.focusNode, secondTextChild);
  assert_equals(selection.focusOffset, 0);
}, "Jump <br> forward which follows a linefeed");

test(() => {
  const preLinefeedBr = document.getElementById("preLinefeedBr");
  selection.collapse(preLinefeedBr, 2);
  selection.modify("move", "backward", "character");
  const textChild = preLinefeedBr.childNodes[0];
  assert_equals(selection.focusNode, textChild);
  assert_equals(selection.focusOffset, textChild.textContent.length);
}, "Jump <br> backward which follows a linefeed");
</script>