Puppeteer page.contentを再帰的反復で取得してページネートリストのすべての結果を取得

Question

私は人形でデータのページリストのすべての結果を取得したいと思います。

私はサイクルのために作る場合、私はこのエラーを与える：

(node:54961) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): Error: Protocol error (Runtime.evaluate): Cannot find context with specified id undefined 

(node:54961) DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code. 

これは私のコードです：

const puppeteer = require('puppeteer'); 
var sleep = require('sleep'); 

function getRandomInt(min, max) { 
    return Math.floor(Math.random() * (max - min + 1)) + min; 
} 

(async() => { 
const browser = await puppeteer.launch({headless: false}); 
const page = await browser.newPage(); 

console.log('start'); 
page.on('console', (...args) => console.log('PAGE LOG:', ...args)); 

await page.goto('pageUrl'); 
var num = 0; 
for(var i=0; i< 10; i++){ 
    var content = await page.content(); 
    console.log('we have content of page '+num); 
    var fs = require('fs'); 
    fs.writeFileSync("htmls/"+num+".html", content); 
    console.log("The file of page "+num+" was saved!"); 

    var sleepSecond = getRandomInt(20,40); 
    console.log("We are waiting "+ sleepSecond + " seconds"); 
    sleep.sleep(sleepSecond); 

    var inputElement = await page.$('a.next'); 
    await inputElement.click(); 
    console.log('Click on next'); 
    sleepSecond = getRandomInt(40,80); 
    console.log("We are waiting "+ sleepSecond + " seconds"); 
    sleep.sleep(sleepSecond); 
    num +=15; 
} 

browser.close(); 
})(); 

それでは、どのようにこのエラーを解決し、どのように再帰的なサイクルでサイクルに変換？

Answer 1

try/catchですべてをラップして解決しました。私は見つけ出した.then() & .catch()の例ですが、このpostにはほとんど簡単すぎる例がありました。

(async() => { 
    try { 
     const browser = await puppeteer.launch({headless: false}); 
     const page = await browser.newPage(); 
     console.log('start'); 
     page.on('console', (...args) => console.log('PAGE LOG:', ...args)); 
     await page.goto('pageUrl'); 
     var num = 0; 
     for(var i=0; i< 10; i++){ 
      var content = await page.content(); 
      console.log('we have content of page '+num); 
      var fs = require('fs'); 
      fs.writeFileSync("htmls/"+num+".html", content); 
      console.log("The file of page "+num+" was saved!"); 

      var sleepSecond = getRandomInt(20,40); 
      console.log("We are waiting "+ sleepSecond + " seconds"); 
      sleep.sleep(sleepSecond); 

      var inputElement = await page.$('a.next'); 
      await inputElement.click(); 
      console.log('Click on next'); 
      sleepSecond = getRandomInt(40,80); 
      console.log("We are waiting "+ sleepSecond + " seconds"); 
      sleep.sleep(sleepSecond); 
      num +=15; 
     } 
     browser.close(); 
    } catch(e) { 
     console.log(e); 
    } 
})();