Tracing misses sometimes the click event

[krausest]

Tracing misses sometimes the click event

[syduki]

It would be hard to spot this just by looking at the code, most probably it would require some debug output here and there to narrow it down.
But from the code in timeline.ts:

if (clicks.length !== 1) {
    console.log("exactly one click event is expected", fileName, events);
    throw "exactly one click event is expected";
}

we can suspect 2 causes:

1. click event not dispatched at all, i.e. puppeteer click event fails silently.
2. more than one click event dispatched, due to some bug/peculiarity of event system in some framework.

Don't you see in the console at least the framework and scenario where this is triggered, or it is a random event?

[krausest]

Such a trace might then look like that:

This feels so odd, since the browser is in a defined state after initBenchmark. The test driver has verified that the warmup was successful and the dom elements are present. Then tracing starts before runBenchmak whose actions are also validated (i.e. it's neither case 1 or 2). The tracing stops after successful verification that the dom state was modified according to the benchmark. Everything is in its place, but the trace contains almost nothing (no click event, no layout, no paint, ...)
Both puppeteer and playwright occasionally have this error, maybe I find the time to check the webdriver CDP driver.

As a workaround I built a retry for that particular error. @syduki I'll close your PR since I played with that retry on the master branch.

[syduki]

Those 1 & 2 were too optimistic, from your capture looks it is a worse case, more likely tied to CDP itself. Let's see if it improves with the webdriver.