javascript chainable promise example

chainable.js

let method1 = function() {
  console.log("method1")
  return true
}

let method2 = function() {
  console.log("method2")
  return true
}

let method3 = function() {
  console.log("method3")
  return true
}

let chainableMethod1 = function() {
  return new Promise(function(resolve, reject) {

    let result = method1()
    if (result) {
      return resolve("method1")
    }
    else {
      return reject("method1")
    }

  });
}

let chainableMethod2 = function() {
  return new Promise(function(resolve, reject) {

    let result = method2()
    if (result) {
      return resolve("method2")
    }
    else {
      return reject("method2")
    }

  });
}

let chainableMethod3 = function() {
  return new Promise(function(resolve, reject) {

    let result = method3()
    if (result) {
      return resolve("method3")
    }
    else {
      return reject("method3")
    }

  });
}

chainableMethod1()
  .then(chainableMethod2)
  .then(chainableMethod3)
  .then(function(res){
    console.log("done")
  })
  .catch(function(err) {
    console.log('error:', err)
  })