is it still useful?

[zzzgit]

const Promi = Promise
module.exports = {
    resolved: function (value) {
        return Promi.resolve(333)
    },
    rejected: function (reason) {
        return Promi.resolve(new Error("444"))
    },
    deferred: function () {
        let res, rej;
        const prom = new Promi((resolve, reject)=>{res = resolve; rej=reject})
        return {
            promise: prom,
            resolve(value){
                res(value)
            },
            reject(reason){
                rej(reason)
            }
        }
    }
};

Even node.js's built-in Promise can't pass these test cases.

many many errors I got....

[poelstra]

Duh, your resolved and rejected functions return custom values, instead of the values passed in by the test.

This one works as expected:

const adapter = {
	deferred: () => {
		let resolve;
		let reject;
		const promise = new Promise((res, rej) => { resolve = res; reject = rej; });
		return {
			promise,
			reject,
			resolve,
		};
	},
	rejected: (reason) => Promise.reject(reason),
	resolved: (value) => Promise.resolve(value),
};

[zzzgit]

const Pinky = Promise
module.exports = {
	resolved: function(value) {
		return Pinky.resolve(value)
	},
	rejected: function(reason) {
		return Pinky.resolve(reason)
	},
	deferred: function() {
		// eslint-disable-next-line @typescript-eslint/no-unused-vars
		let res; let rej
		const prom = new Pinky((resolve, reject) => {
			res = resolve; rej = reject
		})
		return {
			promise: prom,
			resolve: res,
			reject: rej,
		}
	},
}

OK, even though I have changed my code as you mentioned, I still got many errors.

[TotooriaHyperion]

node 14.16.0 passed all the tests.
node 16.13.0 randomly failed around 10~16 tests.

  1)  Uncaught error outside test suite:
     Uncaught UnhandledPromiseRejection: This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason "#<Object>".
  

  2)  Uncaught error outside test suite:
     Uncaught UnhandledPromiseRejection: This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason "#<Object>".
  

  3) 2.3.3: Otherwise, if `x` is an object or function, 2.3.3.3: If `then` is a function, call it with `x` as `this`, first argument `resolvePromise`, and second argument `rejectPromise` 2.3.3.3.1: If/when `resolvePromise` is called with value `y`, run `[[Resolve]](promise, y)` `y` is a thenable for a thenable `y` is an asynchronously-fulfilled custom thenable for an already-rejected promise `then` calls `resolvePromise` synchronously via return from a fulfilled promise:
     Uncaught UnhandledPromiseRejection: This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason "#<Object>".
  

  4) 2.3.3: Otherwise, if `x` is an object or function, 2.3.3.3: If `then` is a function, call it with `x` as `this`, first argument `resolvePromise`, and second argument `rejectPromise` 2.3.3.3.1: If/when `resolvePromise` is called with value `y`, run `[[Resolve]](promise, y)` `y` is a thenable for a thenable `y` is an asynchronously-fulfilled custom thenable for an already-rejected promise `then` calls `resolvePromise` asynchronously via return from a fulfilled promise:
     Uncaught UnhandledPromiseRejection: This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason "#<Object>".
  

  5) 2.3.3: Otherwise, if `x` is an object or function, 2.3.3.3: If `then` is a function, call it with `x` as `this`, first argument `resolvePromise`, and second argument `rejectPromise` Uncaught error outside test suite:
     Uncaught TypeError: Cannot read properties of undefined (reading 'currentRetry')
      at processImmediate (node:internal/timers:464:21)

  6) 2.3.3: Otherwise, if `x` is an object or function, 2.3.3.3: If `then` is a function, call it with `x` as `this`, first argument `resolvePromise`, and second argument `rejectPromise` 2.3.3.3.1: If/when `resolvePromise` is called with value `y`, run `[[Resolve]](promise, y)` `y` is a thenable for a thenable `y` is an eventually-fulfilled promise for an already-rejected promise `then` calls `resolvePromise` synchronously via return from a fulfilled promise:
     Uncaught UnhandledPromiseRejection: This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason "#<Object>".
  

  7) 2.3.3: Otherwise, if `x` is an object or function, 2.3.3.3: If `then` is a function, call it with `x` as `this`, first argument `resolvePromise`, and second argument `rejectPromise` 2.3.3.3.1: If/when `resolvePromise` is called with value `y`, run `[[Resolve]](promise, y)` `y` is a thenable for a thenable `y` is an eventually-fulfilled promise for an already-rejected promise `then` calls `resolvePromise` synchronously via return from a rejected promise:
     Uncaught UnhandledPromiseRejection: This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason "#<Object>".
  

  8) 2.3.3: Otherwise, if `x` is an object or function, 2.3.3.3: If `then` is a function, call it with `x` as `this`, first argument `resolvePromise`, and second argument `rejectPromise` 2.3.3.3.1: If/when `resolvePromise` is called with value `y`, run `[[Resolve]](promise, y)` `y` is a thenable for a thenable `y` is an eventually-fulfilled promise for an already-rejected promise `then` calls `resolvePromise` asynchronously via return from a fulfilled promise:
     Uncaught UnhandledPromiseRejection: This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason "#<Object>".
  

  9) 2.3.3: Otherwise, if `x` is an object or function, 2.3.3.3: If `then` is a function, call it with `x` as `this`, first argument `resolvePromise`, and second argument `rejectPromise` 2.3.3.3.1: If/when `resolvePromise` is called with value `y`, run `[[Resolve]](promise, y)` `y` is a thenable for a thenable `y` is an eventually-fulfilled promise for an already-rejected promise `then` calls `resolvePromise` asynchronously via return from a rejected promise:
     Uncaught UnhandledPromiseRejection: This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason "#<Object>".
  

  10)  Uncaught error outside test suite:
     Uncaught TypeError: Cannot read properties of undefined (reading 'currentRetry')
      at processImmediate (node:internal/timers:464:21)

  11) 2.3.3: Otherwise, if `x` is an object or function, 2.3.3.3: If `then` is a function, call it with `x` as `this`, first argument `resolvePromise`, and second argument `rejectPromise` 2.3.3.3.3: If both `resolvePromise` and `rejectPromise` are called, or multiple calls to the same argument are made, the first call takes precedence, and any further calls are ignored. calling `resolvePromise` synchronously then `rejectPromise` asynchronously Uncaught error outside test suite:
     Uncaught TypeError: Cannot set properties of undefined (setting 'state')
      at onPromiseRejected (node_modules/promises-aplus-tests/lib/tests/2.3.3.js:108:13)

  12) 2.3.3: Otherwise, if `x` is an object or function, 2.3.3.3: If `then` is a function, call it with `x` as `this`, first argument `resolvePromise`, and second argument `rejectPromise` Uncaught error outside test suite:
     Uncaught TypeError: Cannot read properties of undefined (reading 'currentRetry')
      at processImmediate (node:internal/timers:464:21)

  13) 2.3.3: Otherwise, if `x` is an object or function, Uncaught error outside test suite:
     Uncaught TypeError: Cannot read properties of undefined (reading 'currentRetry')
      at processImmediate (node:internal/timers:464:21)

[seandunaway]

% node --version
v20.3.0

794 passing (11s)
14 failing

same 2.3.3 failures

[FaberVitale]

It seems that the test suite fails since node 15 because of the unhandledrejection changes.

globalThis.Promise passes all tests in node 20 & node 18 if an unhandledrejection listener is added in the adapter.

// adapter.js
module.exports = {
  deferred() {
    let resolve, reject;

    const promise = new Promise((res, rej) => {
      resolve = res;
      reject = rej;
    });

    return {
      promise,
      resolve,
      reject,
    };
  },
};

require('process').on('unhandledRejection', (err) => { console.debug('unhandledRejection', err) });

  872 passing (13s)