Do not fatal if manifest is missing (type hinting)

[kadamwhite]

(extracted from a comment on #40)

Probably the biggest risk / gotcha I run into regularly with Asset Loader right now is that if you try to enqueue a file and there is no manifest on disk, get_asset_manifest() returns null which is not a string which causes a 500.

Argument 1 passed to Asset_Loader\enqueue_asset() must be of the type string, null given

This is a rough edge we should probably smooth off, by one or more of

• removing the type constraint
• making the manifest function return an empty string instead of null
• and possibly log a warning within (enqueue|register)_asset if the manifest is missing

I'm personally most in favor of removing the constraint and possibly adding an error, but curious for thoughts. @Sephsekla et al

[Sephsekla]

I think the biggest issue is that it's inconsistent with the behaviour of wp_enqueue_script tbh. In a way I kinda like the fatal, since you'll immediately know about it if a critical asset is missing.

What do you think about some kind of strict mode flag/argument which lets a user decide whether it fatally errors?

[kadamwhite]

Not particularly font of strict modes, it's another layer you need to keep in mind on top of environment, WP_Debug, etc. 🤔

My rough stance here is that there's many things that can cause a build to fail, and I wouldn't want the site to fatal if a plugin was activated without a build process in place or in a situation where assets didn't get omitted as expected. On the sort of sites we work on, as an example, if we were adding a blocks plugin I'd consider it much more desirable to have the site load sans those blocks than to fail to load entirely.

[Sephsekla]

Not particularly font of strict modes, it's another layer you need to keep in mind on top of environment, WP_Debug, etc. 🤔

OK so maybe an explicit argument in the functions?

function enqueue_asset( string $manifest_path, string $target_asset, array $options = [], bool $strict_require = false );

For something like GDPR cookie code for example, it might be desired behaviour to break rather than miss the script.

[kadamwhite]

Fixed in #59