This is a testharness.js-based test.
Found 57 FAIL, 0 TIMEOUT, 0 NOTRUN.
[FAIL] CSSFontFaceDescriptors interface: existence and properties of interface object
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface object length
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface object name
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: existence and properties of interface prototype object
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: existence and properties of interface prototype object's "constructor" property
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: existence and properties of interface prototype object's @@unscopables property
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute src
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute fontFamily
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute font-family
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute fontStyle
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute font-style
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute fontWeight
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute font-weight
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute fontStretch
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute font-stretch
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute fontWidth
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute font-width
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute unicodeRange
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute unicode-range
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute fontFeatureSettings
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute font-feature-settings
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute fontVariationSettings
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute font-variation-settings
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute fontNamedInstance
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute font-named-instance
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute fontDisplay
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute font-display
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute fontLanguageOverride
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute font-language-override
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute ascentOverride
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute ascent-override
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute descentOverride
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute descent-override
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute lineGapOverride
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFaceDescriptors interface: attribute line-gap-override
assert_own_property: self does not have own property "CSSFontFaceDescriptors" expected property "CSSFontFaceDescriptors" missing
[FAIL] CSSFontFeatureValuesRule interface: existence and properties of interface object
assert_own_property: self does not have own property "CSSFontFeatureValuesRule" expected property "CSSFontFeatureValuesRule" missing
[FAIL] CSSFontFeatureValuesRule interface object length
assert_own_property: self does not have own property "CSSFontFeatureValuesRule" expected property "CSSFontFeatureValuesRule" missing
[FAIL] CSSFontFeatureValuesRule interface object name
assert_own_property: self does not have own property "CSSFontFeatureValuesRule" expected property "CSSFontFeatureValuesRule" missing
[FAIL] CSSFontFeatureValuesRule interface: existence and properties of interface prototype object
assert_own_property: self does not have own property "CSSFontFeatureValuesRule" expected property "CSSFontFeatureValuesRule" missing
[FAIL] CSSFontFeatureValuesRule interface: existence and properties of interface prototype object's "constructor" property
assert_own_property: self does not have own property "CSSFontFeatureValuesRule" expected property "CSSFontFeatureValuesRule" missing
[FAIL] CSSFontFeatureValuesRule interface: existence and properties of interface prototype object's @@unscopables property
assert_own_property: self does not have own property "CSSFontFeatureValuesRule" expected property "CSSFontFeatureValuesRule" missing
[FAIL] CSSFontFeatureValuesRule interface: attribute fontFamily
assert_own_property: self does not have own property "CSSFontFeatureValuesRule" expected property "CSSFontFeatureValuesRule" missing
[FAIL] CSSFontFeatureValuesRule interface: attribute annotation
assert_own_property: self does not have own property "CSSFontFeatureValuesRule" expected property "CSSFontFeatureValuesRule" missing
[FAIL] CSSFontFeatureValuesRule interface: attribute ornaments
assert_own_property: self does not have own property "CSSFontFeatureValuesRule" expected property "CSSFontFeatureValuesRule" missing
[FAIL] CSSFontFeatureValuesRule interface: attribute stylistic
assert_own_property: self does not have own property "CSSFontFeatureValuesRule" expected property "CSSFontFeatureValuesRule" missing
[FAIL] CSSFontFeatureValuesRule interface: attribute swash
assert_own_property: self does not have own property "CSSFontFeatureValuesRule" expected property "CSSFontFeatureValuesRule" missing
[FAIL] CSSFontFeatureValuesRule interface: attribute characterVariant
assert_own_property: self does not have own property "CSSFontFeatureValuesRule" expected property "CSSFontFeatureValuesRule" missing
[FAIL] CSSFontFeatureValuesRule interface: attribute styleset
assert_own_property: self does not have own property "CSSFontFeatureValuesRule" expected property "CSSFontFeatureValuesRule" missing
[FAIL] CSSFontFeatureValuesRule interface: attribute historicalForms
assert_own_property: self does not have own property "CSSFontFeatureValuesRule" expected property "CSSFontFeatureValuesRule" missing
[FAIL] CSSFontFeatureValuesMap interface: existence and properties of interface object
assert_own_property: self does not have own property "CSSFontFeatureValuesMap" expected property "CSSFontFeatureValuesMap" missing
[FAIL] CSSFontFeatureValuesMap interface object length
assert_own_property: self does not have own property "CSSFontFeatureValuesMap" expected property "CSSFontFeatureValuesMap" missing
[FAIL] CSSFontFeatureValuesMap interface object name
assert_own_property: self does not have own property "CSSFontFeatureValuesMap" expected property "CSSFontFeatureValuesMap" missing
[FAIL] CSSFontFeatureValuesMap interface: existence and properties of interface prototype object
assert_own_property: self does not have own property "CSSFontFeatureValuesMap" expected property "CSSFontFeatureValuesMap" missing
[FAIL] CSSFontFeatureValuesMap interface: existence and properties of interface prototype object's "constructor" property
assert_own_property: self does not have own property "CSSFontFeatureValuesMap" expected property "CSSFontFeatureValuesMap" missing
[FAIL] CSSFontFeatureValuesMap interface: existence and properties of interface prototype object's @@unscopables property
assert_own_property: self does not have own property "CSSFontFeatureValuesMap" expected property "CSSFontFeatureValuesMap" missing
[FAIL] CSSFontFeatureValuesMap interface: maplike<CSSOMString, [object Object]>
Cannot read properties of undefined (reading 'prototype')
[FAIL] CSSFontFeatureValuesMap interface: operation set(CSSOMString, (unsigned long or sequence<unsigned long>))
assert_own_property: self does not have own property "CSSFontFeatureValuesMap" expected property "CSSFontFeatureValuesMap" missing
Harness: the test ran to completion.