core(tags blocking first-paint): exclude script type=module

[thisizkp]

Fixes #3359

[patrickhulce]

thanks for the contribution @thisizkp! would you mind adding a module entry to our smoketests?

lighthouse/lighthouse-cli/test/fixtures/dobetterweb/dbw_tester.html

Lines 35 to 36 in 76e51f3

	<!-- FAIL: block rendering -->
	<script src="./dbw_tester.js"></script>

[patrickhulce]

Why was this added?

[thisizkp]

to detect the inline modules, type="module" may not be always followed by the src attribute.

<script type="module">
import module from '../example.js';
module.test();
</script>

[patrickhulce]

sure, but I mean we're trying to ignore modules so we'd be pulling them in just to ignore them

[patrickhulce]

let's do tag.getAttribute('type') !== 'module'

[thisizkp]

is this just for readability or anything I'm missing over?
I just wrote like this to make it consistent with the above checks

[patrickhulce]

well the others are like that only because there not using an operator, so yeah just easier to read :)

[thisizkp]

@patrickhulce did those minor fixes, not sure about adding module entry to smoke tests. Can you help me out with any pointers to docs, examples or any resources about doing that?

[patrickhulce]

The two lines I referenced are the best example. Basically you want to copy those two lines in that file, add type="module", and change the comment to say it should pass because it's a module and is not blocking

lighthouse/lighthouse-cli/test/fixtures/dobetterweb/dbw_tester.html

Lines 35 to 36 in 76e51f3

	<!-- FAIL: block rendering -->
	<script src="./dbw_tester.js"></script>

[thisizkp]

Oh, I was thinking may be I should create a new file separately to test module thing and I'm not sure about what to test out in those files. Thanks for that 👍

[thisizkp]

@patrickhulce After that mentioned change I did (locally), smoke tests are failing. Need some more time to fix that issue. Will try and get back to you If I get stuck.

[thisizkp]

After adding this line

<script type="module" src="dbw_tester.js?module"></script>

Smoke tests are failing for uses-http2 and mutation-events. I'm puzzled about how this change can affect that. Any help

[patrickhulce]

You haven't pushed your changes so I'm not sure exactly what's failing 😄 but you've added a new URL so you'll probably need to update the uses-http2 expectation to include 1 more request.

lighthouse/lighthouse-cli/test/smokehouse/dobetterweb/dbw-expectations.js

Lines 35 to 43 in fbe3fda

	'uses-http2': {
	score: false,
	extendedInfo: {
	value: {
	results: {
	length: 15,
	},
	},
	},

(bump line 40 to 16)

mutation events is probably reporting the mutation events fired in dbw_tester.js so let's just change the URL to something that'll 404 like src="sample-module.js", keep it simpler for you :)

[thisizkp]

but if it's just a 404, the test will not give accurate results right?

[patrickhulce]

a blocking script that 404s is still a blocking script so it should work fine for our purposes (you can add src="sample-module.js?delay=500" to make sure it takes a while to return) and it shouldn't impact any of the other expectations other than uses-http2

[thisizkp]

blocked at this - <script type="module" src="./sample-module.js?delay=500"></script> line is being triggered twice.

lighthouse/lighthouse-cli/test/smokehouse/dobetterweb/dbw-expectations.js

Lines 35 to 43 in fbe3fda

	'uses-http2': {
	score: false,
	extendedInfo: {
	value: {
	results: {
	length: 15,
	},
	},
	},

If I bump up this number to 17 instead of 16, it works. But I'm curious about what is triggering it.

[patrickhulce]

If I bump up this number to 17 instead of 16, it works. But I'm curious about what is triggering it.

Seems like chrome double requests 404 modules, so I went ahead and fixed up the smoketests since I've had you churn enough 😄

[patrickhulce]

thanks for helping us out here @thisizkp! 🎉 🎂

[thisizkp]

thank you for helping me out, got stuck so many times... but somehow finally merged 🎉