javascript - puppeteer: wait N seconds before continuing to the next line

Question

In puppeteer I would like to wait a defined time before going to the next line of code.

I've tried to put a setTimeout in an evaluate function but it seems to be simply ignored

console.log('before waiting');
await page.evaluate(async() => {
  setTimeout(function(){
      console.log('waiting');
  }, 4000)
});
console.log('after waiting');

This code don't wait and just write before waiting and after waiting

Do you know how to do this?

Answer 1

You can use a little promise function,

function delay(time) {
   return new Promise(function(resolve) { 
       setTimeout(resolve, time)
   });
}

Then, call it whenever you want a delay.

console.log('before waiting');
await delay(4000);
console.log('after waiting');

If you must use puppeteer use the builtin waitForTimeout function.

await page.waitForTimeout(4000)

If you still want to use page.evaluate, resolve it after 4 seconds. You are not resolving anything.

await page.evaluate(async() => {
    await new Promise(function(resolve) { 
           setTimeout(resolve, 1000)
    });
});

But I guess you can simply use the first two examples.