Inconsistent naming between .resolve() and .fulfilled()

Hello,

I noticed an inconsistency between the aliases of the “return a resolved promise, immediately” method: One is named .resolve(), and the other .fulfilled(). I would expect .resolve() to be called .resolved() (or .fulfilled() -> .fulfill()). By contrast, the “return a rejected promise” method exists as both .rejected() and .reject().

I’ve tried to do .resolved() on more than one occasion, so I thought I’d post this. It isn’t a huge deal, but seeing as this is a beautiful and (otherwise) very consistent library, it might be worth it to create the .fulfill() and .resolved() aliases.

[spion]

Here is the state tree of Promises:

          Pending
Promise /
        \            Locked-in 
          Resolved /
                   \           Fulfilled
                     Settled /
                             \ 
                               Rejected

• Pending - value not known yet, can be changed via resolve or reject
• Resolved - resolve and reject not working anymore
  • Locked-in - … and value not known yet, but it will be the same as the value of another promise
  • Settled - … and value is known
    • Fulfilled - … and value is a fulfilment value (i.e. a normal value, i.e. of “Right” type)
    • Rejected - … and value is a rejection value (i.e. a catchable error, i.e. of “Left” type)

Therefore, fulfil is simply the wrong word. Because the method takes a promise as an argument, and that promise may be rejected with an error (and therefore not fulfilled) resolved is the right word to use - it will either lock-in the promise to another, or settle it with a normal (“Right”) value.

The first version of bluebird used a different terminology, then @domenic made a push to standardise the basic words to be consistent with other libraries, but there are some remaining materials here and there that still use the original method names…

edit: I updated the article to resolve this (no pun intended). Thanks!

[bergus]

@spion Oh of course it’s there: http://www.ecma-international.org/ecma-262/6.0/#sec-promise-objects - and I even have cited that section in my SO answer. I just forgot they used the term “locked in” in the standard.