This is a testharness.js-based test.
[FAIL] RTL text in LTR paragraph: extend right 2 chars
  assert_equals: focusOffset after extend expected 2 but got 6
[FAIL] RTL text in LTR paragraph: extend left 2 chars
  assert_equals: focusOffset after extend expected 4 but got 0
[FAIL] LTR text in RTL paragraph: extend right 2 chars
  assert_equals: focusOffset after extend expected 5 but got 1
[FAIL] LTR text in RTL paragraph: extend left 2 chars
  assert_equals: focusOffset after extend expected 3 but got 7
[FAIL] LTR-RTL context in LTR paragraph: extend right 3 chars
  assert_equals: focusOffset after extend expected 11 but got 7
[FAIL] LTR-RTL context in LTR paragraph: extend left 3 chars
  assert_equals: focusOffset after extend expected 4 but got 8
[FAIL] RTL-LTR context in LTR paragraph: extend right 3 chars
  assert_equals: focusOffset after extend expected 14 but got 10
[FAIL] RTL-LTR context in LTR paragraph: extend left 3 chars
  assert_equals: focusOffset after extend expected 7 but got 11
[FAIL] Mixed context in auto-dir paragraph: extend right 3 chars
  assert_equals: focusOffset after extend expected 5 but got 14
[FAIL] Mixed context in auto-dir paragraph: extend left 3 chars
  assert_equals: focusOffset after extend expected 17 but got 8
Harness: the test ran to completion.