javascript - Regarding Promises/A+ Specification, is a promise ever allowed to never resolve or reject?

Question

In the Promises/A+ standard, I am wondering if a promise needs to resolve or reject eventually. By this I mean a promise X with the property that under no condition whatsoever will X get resolved or rejected.

Promises/A+ states

1. When pending, a promise:

   i. may transition to either the fulfilled or rejected state.

It is the may part that is the ambigious too me. I do not know whether to read it as saying "It may transition but may not" or that it will transition eventually and it may transition to fulfilled or rejected.

Answer 1

No, the spec does not mandate this. There is no restriction on how long a promise should take to settle. And that includes an infinitely long time - known as a never-resolving/never-settling promise or forever-pending promise. (see also promise terminology)
The term may is used deliberately here, and does carry the conventional meaning.

There even exist promise implementations that offer a Promise.never primitive (e.g. in creed) to optimise the memory consumption for the case when you know that your promise won't settle.