//Great solution from Web Dev Simplified: https://www.youtube.com/watch?v=1l4wHWQCCIc (modified slightly so it passes tests here)const STATE = {  FULFILLED: "fulfilled",  REJECTED: "rejected",  PENDING: "pending",}class MyPromise {  #thenCbs = []  #catchCbs = []  #state = STATE.PENDING  #value  #onSuccessBind = this.#onSuccess.bind(this)  #onFailBind = this.#onFail.bind(this)  constructor(executor) {    try {      executor(this.#onSuccessBind, this.#onFailBind)    } catch (e) {      this.#onFail(e)    }  }  #runCallbacks() {    if (this.#state === STATE.FULFILLED) {      this.#thenCbs.forEach(callback => {        callback(this.#value)      })      this.#thenCbs = []    }    if (this.#state === STATE.REJECTED) {      this.#catchCbs.forEach(callback => {        callback(this.#value)      })      this.#catchCbs = []    }  }  #onSuccess(value) {    queueMicrotask(() => {      if (this.#state !== STATE.PENDING) return      if (value instanceof MyPromise) {        value.then(this.#onSuccessBind, this.#onFailBind)        return      }      this.#value = value      this.#state = STATE.FULFILLED      this.#runCallbacks()    })  }  #onFail(value) {    queueMicrotask(() => {      if (this.#state !== STATE.PENDING) return      if (value instanceof MyPromise) {        value.then(this.#onSuccessBind, this.#onFailBind)        return      }      if (this.#catchCbs.length === 0) {        console.error('error' + value)      }      this.#value = value      this.#state = STATE.REJECTED      this.#runCallbacks()    })  }  then(thenCb, catchCb) {    return new MyPromise((resolve, reject) => {      this.#thenCbs.push(result => {        if (thenCb == null) {          resolve(result)          return        }        try {          resolve(thenCb(result))        } catch (error) {          reject(error)        }      })      this.#catchCbs.push(result => {        if (catchCb == null) {          reject(result)          return        }        try {          resolve(catchCb(result))        } catch (error) {          reject(error)        }      })      this.#runCallbacks()    })  }  catch(cb) {    return this.then(undefined, cb)  }  finally(cb) {    return this.then(      result => {        cb()        return result      },      result => {        cb()        throw result      }    )  }  static resolve(value) {    return new Promise(resolve => {      resolve(value)    })  }  static reject(value) {    return new Promise((resolve, reject) => {      reject(value)    })  }  static all(promises) {    const results = []    let completedPromises = 0    return new MyPromise((resolve, reject) => {      for (let i = 0; i < promises.length; i++) {        const promise = promises[i]        promise          .then(value => {            completedPromises++            results[i] = value            if (completedPromises === promises.length) {              resolve(results)            }          })          .catch(reject)      }    })  }  static allSettled(promises) {    const results = []    let completedPromises = 0    return new MyPromise(resolve => {      for (let i = 0; i < promises.length; i++) {        const promise = promises[i]        promise          .then(value => {            results[i] = { status: STATE.FULFILLED, value }          })          .catch(reason => {            results[i] = { status: STATE.REJECTED, reason }          })          .finally(() => {            completedPromises++            if (completedPromises === promises.length) {              resolve(results)            }          })      }    })  }  static race(promises) {    return new MyPromise((resolve, reject) => {      promises.forEach(promise => {        promise.then(resolve).catch(reject)      })    })  }  static any(promises) {    const errors = []    let rejectedPromises = 0    return new MyPromise((resolve, reject) => {      for (let i = 0; i < promises.length; i++) {        const promise = promises[i]        promise.then(resolve).catch(value => {          rejectedPromises++          errors[i] = value          if (rejectedPromises === promises.length) {            reject(new AggregateError(errors, "All promises were rejected"))          }        })      }    })  }}