Deduping fetches

[jakearchibald]

If I fetch('import:whatever') twice, does it go to the network twice or dedupe in the way import('whatever') would?

Also:

const module1 = import('whatever');
const module2 = import('import:whatever');

Are the modules equal in the above example?

[matthewp]

Interesting question. I would expect import: to only affect resolution, and not have everything be stored in the module map. However, there are some scenarios where you might want the deduplication (inside a css @import is one I'm thinking of). So I could see import: being a nice way to opt different resources into the module fetching algorithm.

[domenic]

If I fetch('import:whatever') twice, does it go to the network twice or dedupe in the way import('whatever') would?

The current intention is that it would go to the network (or memory cache, or wherever) twice. The import map only controls the specifier -> fetchable URL translation (including import:someSpecifier -> HTTPS URL). This is vaguely written down in https://github.com/domenic/import-maps/blob/master/spec.md#import-url-fetches; we could keep this open until it gets more concrete, though.

Also:

import('import:whatever') will not work, as import:whatever is not a fetch-schemed URL. See tests in the reference implementation.