CSS Error Source Element

[jabcreations]

Often when a CSS error occurs such as an invalid property name or value there is no reference to little-to-no meaningful context.

• Which element?
• Which property, value, etc?
• Was this inline or defined in a style sheet?

I propose browser vendors work to improve CSS error reporting so these issues can be reported.

Additionally while it may not be considered directly related I think it would be a great idea to allow CSS error reporting. How often do many of us encounter can-not-reproduce-error instances? If we have a JavaScript API where a CSS error report event existed we could know something went wrong, determine what went wrong and actually fix it in spite of being unable to directly reproduce the error ourselves.

[mmocny]

My interpretation of this feature request is that you would like access to this diagnostic data in real time (i.e. from a JS based API on the page?). If so, while the use case sounds reasonable, I am not sure if this is a good fit for the Reporting API specifically, which is more about out-of-band reporting back to a server for issues which cannot be diagnosed on the client by more typical RUM diagnostic methods.

Does that make sense? I am not sure where best to route your request, as I'm not sure if it belongs specifically to a performance API or more related to CSS working area broadly.

[mmocny]

Ping?

My suggestion is:

• If this is requesting better development-time / lab tooling for CSS errors, then maybe this is a feature request for individual browser teams?

• If this is actually about field-data measurement (and I'm not sure I see the need), then I think this might still not be a good fit for the Reporting API specifically (see below), and I'm not sure if there is an existing Performance timeline API for it. This might be a good fit for a proposal for WICG?

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From MDN:

The Reporting API provides a generic reporting mechanism for web applications to use to make reports available based on various platform features (for example Content Security Policy, Permissions-Policy, or feature deprecation reports) in a consistent manner.

[jabcreations]

What is the name of this standard? Reporting. What is one of the goals of standardizing reporting? Consistency. While you quoted more advanced aspects of web development the basics still remain huddling naked and cold in deep dark dank caves. The 100th floor of a building serves no purpose if there are no elevators or stairs on the first. Almost every website has numerous basic simple errors that aren't even reported and the few that are have little-to-no meaningful debugging information. If that is not something to be standardized then nothing is worth standardizing.