Jacek Caban (@jacek) commented about dlls/mshtml/tests/es5.js:
+ ok(arr.byteOffset === 0, name + "(9.1).byteOffset = " + arr.byteOffset); + ok(arr.length === 9, name + "(9.1).length = " + arr.length); + ok(arr.buffer.byteLength === arr.byteLength, name + "(9.1).buffer.byteLength = " + arr.buffer.byteLength); + for(var j = 0; j < 9; j++) + ok(arr[j] === 0, "arr[" + j + "] = " + arr[j]); + arr[5] = 42; + ok(arr[5] === 42, name + "(9.1)[5] = " + arr[5]); + arr[9] = 50; + ok(arr[9] === undefined, name + "(9.1)[9] = " + arr[9]); + + arrType.prototype[6] = "foo"; + r = arrType.prototype[6]; + ok(r === undefined, name + ".prototype[6] = " + r); + ok(arr[6] === 0, name + "(9.1)[6] after set in prototype = " + arr[6]); + arr[6] = 0; + ok(Object.prototype.hasOwnProperty.call(arr, "6"), "'6' not a property of " + name + "(9.1)[6]"); That's `arr.hasOwnProperty(...)`, there is more of those.
-- https://gitlab.winehq.org/wine/wine/-/merge_requests/9275#note_119821