This is a testharness.js-based test.
[FAIL] Property position-visibility value 'anchors-valid'
  assert_true: 'anchors-valid' is a supported value for position-visibility. expected true got false
[FAIL] Property position-visibility value 'anchors-valid anchors-visible'
  assert_true: 'anchors-valid anchors-visible' is a supported value for position-visibility. expected true got false
[FAIL] Property position-visibility value 'anchors-valid no-overflow'
  assert_true: 'anchors-valid no-overflow' is a supported value for position-visibility. expected true got false
[FAIL] Property position-visibility value 'anchors-visible anchors-valid'
  assert_true: 'anchors-visible anchors-valid' is a supported value for position-visibility. expected true got false
[FAIL] Property position-visibility value 'no-overflow anchors-valid'
  assert_true: 'no-overflow anchors-valid' is a supported value for position-visibility. expected true got false
[FAIL] Property position-visibility value 'anchors-valid anchors-visible no-overflow'
  assert_true: 'anchors-valid anchors-visible no-overflow' is a supported value for position-visibility. expected true got false
[FAIL] Property position-visibility value 'anchors-valid no-overflow anchors-visible'
  assert_true: 'anchors-valid no-overflow anchors-visible' is a supported value for position-visibility. expected true got false
[FAIL] Property position-visibility value 'anchors-visible anchors-valid no-overflow'
  assert_true: 'anchors-visible anchors-valid no-overflow' is a supported value for position-visibility. expected true got false
[FAIL] Property position-visibility value 'anchors-visible no-overflow anchors-valid'
  assert_true: 'anchors-visible no-overflow anchors-valid' is a supported value for position-visibility. expected true got false
[FAIL] Property position-visibility value 'no-overflow anchors-valid anchors-visible'
  assert_true: 'no-overflow anchors-valid anchors-visible' is a supported value for position-visibility. expected true got false
[FAIL] Property position-visibility value 'no-overflow anchors-visible anchors-valid'
  assert_true: 'no-overflow anchors-visible anchors-valid' is a supported value for position-visibility. expected true got false
Harness: the test ran to completion.