import get from 'lodash-es/get.js'
import genPm from './genPm.mjs'
import isfun from './isfun.mjs'
import ispm from './ispm.mjs'
/**
* 將Promise函式的resolve與reject皆轉為resolve
*
* 回傳之Promise只會resolve且不產生未處理之rejection：fn同步拋錯(含拋出null)與其Promise被reject皆為error，掛載then或讀取拒絕值時拋錯者(如標籤為Promise卻無可用之then、已撤銷之Proxy、會拋錯之getter)亦為error。惟fn回傳永不settle之Promise或永不呼叫回呼之thenable時亦不settle，需逾時者以pmTimeout包裝
*
* 取消依拒絕值之形狀判定(其reason為'cancelled')，原拒絕值不保留，同步拋出之值不判取消。拒絕值來自外部(應用端、伺服器)而不屬wsemi之取消家族(pmQueue之takeLast、pmThrottle、pmInvResolve)時，勿以本函數分類，否則形似{ reason: 'cancelled' }之外部值會被改判為取消
*
* Unit Test: {@link https://github.com/yuda-lyu/wsemi/blob/master/test/pmConvertResolve.test.mjs Github}
* @memberOf wsemi
* @param {Function} fn 輸入函數，可支援async與sync函數
* @returns {Function} 回傳包裝函數，呼叫後回傳Promise，只會resolve物件資料，物件欄位有state與msg，state可有success、error與cancelled。success之msg為回傳值或resolve值，error之msg為拋出值或reject值(判定拋錯時為該錯誤)，cancelled代表reject回傳{ reason: 'cancelled' }，其msg為空字串；fn非函數時於本函數呼叫當下同步拋出Error('fn is not a function')
* @example
*
* async function topAsync() {
*
* async function test1() {
* return new Promise((resolve, reject) => {
* let ms = []
*
* function fun1(c) {
* return new Promise((resolve, reject) => {
* setTimeout(function() {
* console.log('resolve fun1: ' + c)
* ms.push('resolve fun1: ' + c)
* resolve('fun1: ' + c)
* }, 1)
* })
* }
*
* pmConvertResolve(fun1)('abc')
* .then((msg) => {
* console.log('t1 then: ', msg)
* ms.push({ mode: 't1 then', msg })
* })
* .catch((msg) => {
* console.log('t1 catch: ', msg)
* ms.push({ mode: 't1 catch', msg })
* })
* .finally(() => {
* resolve(ms)
* })
*
* })
* }
* console.log('test1')
* let r1 = await test1()
* console.log(JSON.stringify(r1))
* // test1
* // resolve fun1: abc
* // t1 then: { state: 'success', msg: 'fun1: abc' }
* // ["resolve fun1: abc",{"mode":"t1 then","msg":{"state":"success","msg":"fun1: abc"}}]
*
* async function test2() {
* return new Promise((resolve, reject) => {
* let ms = []
*
* function fun1(c) {
* return new Promise((resolve, reject) => {
* setTimeout(function() {
* console.log('reject fun1: ' + c)
* ms.push('reject fun1: ' + c)
* reject('fun1: ' + c)
* }, 1)
* })
* }
*
* pmConvertResolve(fun1)('abc')
* .then((msg) => {
* console.log('t1 then: ', msg)
* ms.push({ mode: 't1 then', msg })
* })
* .catch((msg) => {
* console.log('t1 catch: ', msg)
* ms.push({ mode: 't1 catch', msg })
* })
* .finally(() => {
* resolve(ms)
* })
*
* })
* }
* console.log('test2')
* let r2 = await test2()
* console.log(JSON.stringify(r2))
* // test2
* // reject fun1: abc
* // { state: 'error', msg: 'fun1: abc' }
* // ["reject fun1: abc",{"mode":"t1 then","msg":{"state":"error","msg":"fun1: abc"}}]
*
* async function test3() {
* return new Promise((resolve, reject) => {
* let ms = []
*
* function fun1(p1, p2) {
* return new Promise((resolve, reject) => {
* setTimeout(function() {
* console.log('resolve fun1: ' + p1 + ', ' + p2)
* ms.push('resolve fun1: ' + p1 + ', ' + p2)
* resolve('fun1: ' + p1 + ', ' + p2)
* }, 1)
* })
* }
*
* pmConvertResolve(fun1)('abc', 'def')
* .then((msg) => {
* console.log('t1 then: ', msg)
* ms.push({ mode: 't1 then', msg })
* })
* .catch((msg) => {
* console.log('t1 catch: ', msg)
* ms.push({ mode: 't1 catch', msg })
* })
* .finally(() => {
* resolve(ms)
* })
*
* })
* }
* console.log('test3')
* let r3 = await test3()
* console.log(JSON.stringify(r3))
* // test3
* // resolve fun1: abc, def
* // t1 then: { state: 'success', msg: 'fun1: abc, def' }
* // ["resolve fun1: abc, def",{"mode":"t1 then","msg":{"state":"success","msg":"fun1: abc, def"}}]
*
* async function test4() {
* return new Promise((resolve, reject) => {
* let ms = []
*
* async function fun1(p1, p2) {
* console.log('resolve fun1: ' + p1 + ', ' + p2)
* return 'fun1: ' + p1 + ', ' + p2
* }
*
* pmConvertResolve(fun1)('abc', 'def')
* .then((msg) => {
* console.log('t1 then: ', msg)
* ms.push({ mode: 't1 then', msg })
* })
* .catch((msg) => {
* console.log('t1 catch: ', msg)
* ms.push({ mode: 't1 catch', msg })
* })
* .finally(() => {
* resolve(ms)
* })
*
* })
* }
* console.log('test4')
* let r4 = await test4()
* console.log(JSON.stringify(r4))
* // test4
* // t1 then: { state: 'success', msg: 'fun1: abc, def' }
* // ["resolve fun1: abc, def",{"mode":"t1 then","msg":{"state":"success","msg":"fun1: abc, def"}}]
*
* }
* topAsync().catch(() => {})
*
*/
function pmConvertResolve(fn) {
//check
if (!isfun(fn)) {
throw new Error(`fn is not a function`)
}
return function() {
let pm = genPm()
//call, 同步拋錯一律為error, 不以拋出值是否為null判定有無拋錯(拋出null亦為error), 同步拋出之值不判取消
let ret
try {
ret = fn.apply(this, arguments)
}
catch (err) {
pm.resolve({
state: 'error',
msg: err,
})
return pm
}
//onReject, 依拒絕值之形狀判取消, 讀取拋錯者(已撤銷之Proxy、會拋錯之getter或陷阱)視為一般錯誤且msg為原拒絕值, 使本回呼必不拋錯
let onReject = (msg) => {
let isCancelled = false
try {
isCancelled = get(msg, 'reason') === 'cancelled'
}
catch (err) {}
if (isCancelled) {
pm.resolve({
state: 'cancelled',
msg: '',
})
}
else {
pm.resolve({
state: 'error',
msg,
})
}
}
//判定與掛載, 判定是否為Promise或掛載then時拋錯者(如標籤為Promise卻無可用之then)視為error且msg為該錯誤
//只呼叫一次then並同時給成功與失敗回呼: 二回呼皆不拋錯, 不依賴then回傳物件之catch(覆寫catch之子類別、then回傳非Promise之thenable皆可正確判定)
try {
if (ispm(ret)) {
ret.then((msg) => {
pm.resolve({
state: 'success',
msg,
})
}, onReject)
}
else {
pm.resolve({
state: 'success',
msg: ret,
})
}
}
catch (err) {
pm.resolve({
state: 'error',
msg: err,
})
}
return pm
}
}
export default pmConvertResolve