javascript - Puppeteer: interact with dom in waitForSelector handler -

when use puppeteer js web crawler, in waitforselector handler can use console.log without trouble:

page   .waitforselector('input[value=update]')   .then(() => {     console.log('this is');     console.log('it');   }); 

but have error when want interact dom:

page   .waitforselector('input[value=update]')   .then(() => {     const inputvalidate = await page.$('input[value=update]');   }); 

this code triggers error:

const inputvalidate = await page.$('input[value=update]'); ^^^^

syntaxerror: unexpected identifier @ createscript (vm.js:74:10) @ object.runinthiscontext (vm.js:116:10) @ module._compile (module.js:537:28) @ object.module._extensions..js (module.js:584:10) @ module.load (module.js:507:32) @ trymoduleload (module.js:470:12) @ function.module._load (module.js:462:3) @ function.module.runmain (module.js:609:10) @ startup (bootstrap_node.js:158:16) @ bootstrap_node.js:598:3

do know how intercat dom in waitforselector handler without trigger error?

page   .waitforselector('input[value=update]')   .then(async() => {     const inputvalidate = await page.$('input[value=update]');   });