[BUG] Does not provide fallback content when JavaScript is not available

[ghost]

Bug report

Provide the steps to reproduce

1. Run LH on

What is the current behavior?

If I use this code (example code):

<noscript>
	<iframe src="noscript.html" frameborder="0" style="height: 100%; width: 100%;"></iframe>
	<noframes>You maybe have disabled JavaScript and Frames, please enable JavaScript or frames in You browser. More info: <br>
		<a href="http://tutorial.com/how-to-enable-js">How to enable JavaScript</a> <br>
		<a href="http://tutorial.com/how-to-enable-frames">How to enable frames</a>
	</noframes>
</noscript>

What is the expected behavior?

do not report warning

Environment Information

• Affected Channels:
  *Chrome: 67.0.3396.99
  a337fbf3c2ab8ebc6b64b0bfdce73a20e2e2252b-refs/branch-heads/3396@{Add ignore pattern, Change template file name. #790}
• Operating System: Windows 10

V8 6.7.288.46
Related issues

[patrickhulce]

I suppose it's arguable if an iframe is sufficient content when script is not enabled. Traversing the entire frame tree to find text is a lot of complexity to add for a minimally useful audit.

Aside: curious why not just redirect to the noscript page if the iframe is the only intended content?

[ghost]

that code was only for example,... but I think, it does not report warning when someone use code similiar to that in example. Maybe lighthouse need only look if noscript tag is in webpage, and if it isn't empty.

[sekisanchi]

Phishtank needs this improvement, I guess.

[patrickhulce]

Maybe lighthouse need only look if noscript tag is in webpage, and if it isn't empty.

That's a good idea 👍 the only point of the audit is to force the developer to consider the noscript case :)