Text methods report a clear error on an empty or missing value

Text handling brought closer to the standard. Calling a text method with nothing to work on, when the value is empty or missing, now reports a clear error the way every other browser does, instead of quietly treating it as the words null or undefined and carrying on with the wrong result. The same clear error is reported for the special symbol values that cannot be turned into text. Every other value keeps working exactly as before. Code that was already correct is unchanged. The JavaScript language aspect moves 98 to 99; the overall platform score stays at 70.

Parity with the reference browser

74overall, as of v0.1.355

Web APIs / DOM surface53

Security architecture66

GPU / graphics acceleration68

DevTools / extensions72

Networking85

Media85

Accessibility85

Real-world site compatibility99

HTML parsing100

CSS parsing + selectors100

Layout: block / flex / grid / tables / writing-modes100

Paint + visual100

JavaScript language100

JavaScript performance (JIT)100

HTML parsing100

What changed 3 changes

Rendering	Text methods reject an empty or missing value. Calling a built-in text method on a value that is empty or missing now reports a clear error the moment it happens, as the standard requires, rather than silently treating the value as the literal words null or undefined and returning a misleading result.
Rendering	Symbol values are rejected the same way. Passing one of the special symbol values, which cannot be turned into text, as the thing a text method works on now reports the same clear error instead of producing a placeholder string.
Rendering	Every valid value still works. Ordinary text, numbers, true-or-false values, and wrapped text are all still accepted and processed exactly as before, so only the genuinely invalid cases are affected.