[kbolino]

Assuming assert existed, it would almost certainly be judging its value for being falsy, while the ?? operator judges its LHS for being nullish, which is a narrower category. For strings, this affects whether the empty string is acceptable or not.

[xscott]

> Assuming assert existed

It's a function you could write for yourself and give it whatever semantics you feel is best. No changes to the language required for this one.

[fainpul]

  console.assert(maybeNull != null, 'variable not set')

[kbolino]

Fair, this is a good example of when != is actually the right choice (instead of !==). However, on web browsers, this will log an assertion failure to the console, but it will not throw an exception. It's also not suitable for the original context, where the non-null value was extracted into a variable.