Support for Schema-relative URL for remote images

[saneef]

The schema-relative or protocol relative URLs are common while porting old sites to Eleventy.

<img
  alt="A head of a tiger"
  src="//upload.wikimedia.org/wikipedia/commons/f/fd/Ghostscript_Tiger.svg"
>

Presently, when using such URL, new Image() gives the error:

Error: ENOENT: no such file or directory, stat '//upload.wikimedia.org/wikipedia/commons/f/fd/Ghostscript_Tiger.svg'

Is adding support for schema-relative URLs useful for our users?

See: saneef/eleventy-plugin-img2picture#27

[zachleat]

Relative to what? Should we make an opinionated choice here and assume https? (I’d be on board with that)

Notably, new URL("//upload.wikimedia.org/wikipedia/commons/f/fd/Ghostscript_Tiger.svg") throws an error.

[saneef]

Yes, assuming https looks sensible and safer approach.

[saneef]

It got me thinking, should this be actually part of the elevent-img. Something that new URL() would not accept as valid?

Can it be a separate utility or a plugin that people can use before eleventy-img?