[Feature] add a timeout parameter to locator.count()

[TimeInvestor]

For now, locator.count() returns immediately. If the element(s) take time to load, then the count is not accurate.
It would be nice if users could specify a wait time (or timeout) for the function.

Context: I am using if(locator.count()) > 0) to check element existence in my Page Object since there lacks a straightforward way to achive such goal.

[mxschmitt]

You can use toHaveCount which has automatic retries etc. see here: https://playwright.dev/docs/test-assertions#expectlocatortohavecountcount

Does this work for you?

[aslushnikov]

@TimeInvestor you might also find expect(locator).toBeVisible() to be very useful for this usecase

[TimeInvestor]

@mxschmitt expect(locator).toHaveCount(count) is not helpful in my case as I don't know how many elements to expect and my code don't care that either. I just want to check if elements of a selector exist or not (i.e. visible). If none exists, then I need to take some action.

@aslushnikov expect(locator).toBeVisible() will fail the test, right? which is not what I want.

[aslushnikov]

will fail the test, right? which is not what I want.

@TimeInvestor Well it will, if there's no visible element. In this case, what you need is expect(locator).toExist()?

[ltsuda]

@aslushnikov maybe @TimeInvestor could use this in the next version?
#9200

[TimeInvestor]

will fail the test, right? which is not what I want.

@TimeInvestor Well it will, if there's no visible element. In this case, what you need is expect(locator).toExist()?

I don't plan to use expect(...) as what I need is not to assert something, but to check if element(s) exist or not. If yes, do something; if not, do something else.

[TimeInvestor]

@aslushnikov maybe @TimeInvestor could use this in the next version? #9200

The locator.waitFor(..) sounds promising. It defenitely will benefit my test automation project. But for this case, I am not sure if it will be helpful. What will happen for locator.waitFor(...) when an element does not exist? Will it throw an error or returns null?

[ltsuda]

@aslushnikov maybe @TimeInvestor could use this in the next version? #9200

The locator.waitFor(..) sounds promising. It defenitely will benefit my test automation project. But for this case, I am not sure if it will be helpful. What will happen for locator.waitFor(...) when an element does not exist? Will it throw an error or returns null?

I'm sorry, I think it will throw an error so it might not help your case.

[yury-s]

But for this case, I am not sure if it will be helpful. What will happen for locator.waitFor(...) when an element does not exist? Will it throw an error or returns null?

See locator.waitFor which is already available in @next. If the condition is not met before specified timeout it will throw but that should work for your case, something like this:

try {
  // The locator will resolve when there is at least one such element
  await locator.first().waitFor({ timeout: 5_000 });
  // run the code for the case of count > 0
} catch (e) {
  // handle the case when the count is 0.
}

You can also add extra check that the error is actually a timeout error.

[mskonst]

I had the same problem. I had two buttons to appear and I didn't know what button was currently on the page. I used count() to know whether the locators for this button existed. And count () returned 0 for the existed locator. So I added the delay in one sec before the locator's counting.

import { delay } from './utils';

await delay(1000, null);
const locator = page.locator('[aria-label="Delete\ the\ API\ key"]');
const count = await locator.count();
console.log('count ', count);

and got

> count 1

delay() function I implemented in and imported from the file utils.ts:

export function delay<T>(milliseconds: number, value: T): Promise<T> {
    return new Promise(function(resolve) { 
        setTimeout(resolve.bind(null, value), milliseconds)
    });
}