Javascript 如何预防';未经处理的PromiserRejection';用户输入错误?
我有两个文件,main.js和input.js。 在input.js中,我提示用户以“1-10”(字符串)格式给我一个间隔。稍后,我剪切此字符串并从中获取2个数字,并检查数字是否正确:Javascript 如何预防';未经处理的PromiserRejection';用户输入错误?,javascript,node.js,promise,async.js,Javascript,Node.js,Promise,Async.js,我有两个文件,main.js和input.js。 在input.js中,我提示用户以“1-10”(字符串)格式给我一个间隔。稍后,我剪切此字符串并从中获取2个数字,并检查数字是否正确: let getInput = () => { return new Promise(function (resolve, reject) { readline.question(`Give me interval (e.g.: 1-10).\n`, (input) => { l
let getInput = () => {
return new Promise(function (resolve, reject) {
readline.question(`Give me interval (e.g.: 1-10).\n`, (input) => {
let fields = input.split('-');
let startNumber = Number(fields[0]);
let endNumber = Number(fields[1]);
if ((startNumber) && (endNumber) && (startNumber > 0) && (endNumber >= startNumber)) {
console.log(`ok`);
readline.close()
resolve([startNumber, endNumber]);
} else {
reject('not ok');
getInput();
}
});
});
}
在main.js中,我异步调用此函数,并将其结果保存到一个变量中:
let intervalArray = await getInput();
.
.
.
someotherstuff
我的问题是如果我提供了错误的输入(例如“0-1”或“10-9”或“-10”)
我有一个未处理的Promise错误,因此代码不会执行更多。
我的目标是当用户输入错误时,控制台中会出现“不正常,给我另一个”,程序应该等待另一个输入。如果输入正确,则继续执行。如果没有,程序应该请求另一个输入
我怎样才能做到这一点
编辑:
这是完整的代码。
Input.js:
const readline = require('readline').createInterface({
input: process.stdin,
output: process.stdout
});
let getInput = () => {
return new Promise(function (resolve, reject) {
readline.question(`tol-ig formatumban (pl.: 1-10).\n`, (data) => {
let fields = data.split('-');
let startNumber = Number(fields[0]);
let endNumber = Number(fields[1]);
if ((startNumber) && (endNumber) && (startNumber > 0) && (endNumber >= startNumber)) {
console.log(`Kereses inditasa ${startNumber}-${endNumber} oldalakon.`);
readline.close()
resolve([startNumber, endNumber]);
} else {
readline.close();
reject(new Error('not ok'));
}
});
});
}
module.exports.getInput = getInput;
和main.js:
const puppeteer = require('puppeteer');
const { getInput } = require('./input');
const { mouseMovements } = require('./mouse');
const { tuneUserAgent } = require('./userAgent');
async function listItems() {
let intervalArray = null;
while (intervalArray === null) {
try {
let intervalArray = await getInput();
} catch (err) {
// write to user not ok
}
}
const browser = await puppeteer.launch({ headless: false });
const context = await browser.createIncognitoBrowserContext();
const page = await context.newPage();
const extractPartners = async url => {
const page = await context.newPage();
await tuneUserAgent(page);
await page.goto(url, { waitUntil: 'load' });
await page.waitFor(Math.round(Math.random() * 500) + 500);
await mouseMovements(page);
const partnersOnPage = await page.evaluate(() =>
Array.from(document.querySelectorAll("div.compact"))
.map(compact => (compact.querySelector(".logo a").href.slice(-16))));
await page.close();
const nextPageNumber = parseInt(url.match(/page=(\d+)$/)[1], 10) + 1;
if (nextPageNumber > endPage) {
console.log(`Terminate recursion on: ${url}`);
return partnersOnPage;
} else {
console.log(`Scraped: ${url}`);
const nextUrl = `https://marketingplatform.google.com/about/partners/find-a-partner?page=${nextPageNumber}`;
let randomWait = (Math.round(Math.random() * 2000) + 1000);
await page.waitFor(randomWait);
return partnersOnPage.concat(await extractPartners(nextUrl));
}
};
let startPage = intervalArray[0];
let endPage = intervalArray[1];
const firstUrl =
`https://marketingplatform.google.com/about/partners/find-a-partner?page=${startPage}`;
const partners = await extractPartners(firstUrl);
await browser.close();
return Promise.resolve(partners);
};
module.exports.listItems = listItems;
你必须处理这个错误。在使用wait时,最简单的方法是使用try-catch
try {
let intervalArray = await getInput();
} catch (err) {
// write to user not ok
}
您可以将其包装在循环中,以不断请求用户输入新的输入
let intervalArray = null;
while (intervalArray === null) {
try {
let intervalArray = await getInput();
} catch (err) {
// write to user not ok
}
}
^^记住删除getInput()代码>来自新承诺的部分。也许您还需要关闭readline,因为您将再次打开它。另外,拒绝类似于抛出错误,您应该始终将基于错误的对象发送到那里
} else {
readline.close();
reject(new Error('not ok'));
}
编辑:更新后我创建了POC。readline.close()
实际上不应该在那里(看起来只是一次性使用),但是这个POC看起来很好:
toberrequired.js
const readline = require('readline').createInterface({
input: process.stdin,
output: process.stdout
});
let getInput = () => {
return new Promise(function (resolve, reject) {
readline.question(`tol-ig formatumban (pl.: 1-10).\n`, (data) => {
let fields = data.split('-');
let startNumber = Number(fields[0]);
let endNumber = Number(fields[1]);
if ((startNumber) && (endNumber) && (startNumber > 0) && (endNumber >= startNumber)) {
console.log(`Kereses inditasa ${startNumber}-${endNumber} oldalakon.`);
readline.close()
resolve([startNumber, endNumber]);
} else {
reject(new Error('not ok'));
}
});
});
}
module.exports.getInput = getInput;
const a = require('./toBeRequired');
async function x() {
let input = null;
while (input === null) {
try {
input = await a.getInput();
} catch (err) {
console.log('nooo');
}
}
}
x();
server.js
const readline = require('readline').createInterface({
input: process.stdin,
output: process.stdout
});
let getInput = () => {
return new Promise(function (resolve, reject) {
readline.question(`tol-ig formatumban (pl.: 1-10).\n`, (data) => {
let fields = data.split('-');
let startNumber = Number(fields[0]);
let endNumber = Number(fields[1]);
if ((startNumber) && (endNumber) && (startNumber > 0) && (endNumber >= startNumber)) {
console.log(`Kereses inditasa ${startNumber}-${endNumber} oldalakon.`);
readline.close()
resolve([startNumber, endNumber]);
} else {
reject(new Error('not ok'));
}
});
});
}
module.exports.getInput = getInput;
const a = require('./toBeRequired');
async function x() {
let input = null;
while (input === null) {
try {
input = await a.getInput();
} catch (err) {
console.log('nooo');
}
}
}
x();
在同一个文件夹中创建这两个文件并运行node server.js
我已经用您的解决方案更新了我的代码,但它是相同的;在输入错误的情况下,我得到了承诺错误,执行停止。@ConTroll-然后用您现在的完整解决方案更新您的问题,可能还有一些您不知道的错误。@ConTroll-现在可能是不同的错误。你可以从我的POC开始,然后继续添加内容。此外,您还应该看到error stacktrace,它应该告诉您错误的位置以及原因。
const readline = require('readline').createInterface({
input: process.stdin,
output: process.stdout
});
let getInput = () => {
return new Promise(function (resolve, reject) {
readline.question(`tol-ig formatumban (pl.: 1-10).\n`, (data) => {
let fields = data.split('-');
let startNumber = Number(fields[0]);
let endNumber = Number(fields[1]);
if ((startNumber) && (endNumber) && (startNumber > 0) && (endNumber >= startNumber)) {
console.log(`Kereses inditasa ${startNumber}-${endNumber} oldalakon.`);
readline.close()
resolve([startNumber, endNumber]);
} else {
reject(new Error('not ok'));
}
});
});
}
module.exports.getInput = getInput;
const a = require('./toBeRequired');
async function x() {
let input = null;
while (input === null) {
try {
input = await a.getInput();
} catch (err) {
console.log('nooo');
}
}
}
x();