feat(cli): allow import maps from url

[futurist]

This PR should resolved #5522 .

One thing related to the cache, the import map file has the same behavior with module files.

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[futurist]

The tests of last commit shows a pending problem:

how to calculate the base_url of "scopes" in importmap?

The ignored test _033_import_map_http_local_entry will fail, let's see why:

Currently the base_url is from importmap arg,

See:

The URL of the import map is the base URL for its values.

deno/cli/import_map.rs

Line 70 in 9090023

ImportMap::from_json(&file_url, &json_string).map_err(ErrBox::from)

So the below command:

$ deno run --quiet --reload --allow-net \
     --importmap=http://127.0.0.1:4545/cli/tests/importmaps/import_map.json \
     --unstable importmaps/test.ts

The content of test.ts:

......
import "./scope/scoped.ts";

produces the scope url of ./scope/scoped.ts from importmap view:

http://127.0.0.1:4545/cli/tests/importmaps/scope/scoped.ts

but in the test.ts file's view, the url of scope/scoped.ts has file:// schema, just like a local file, which doesn't match the scope of importmap above, thus the "scopes" rule in import_map.json omitted.

I think this should be think carefully and decide the right algorithm.

Or, the test ignored should be really ignored and keep the current algorithm?

[bartlomieju]

Thanks for opening the PR @futurist.

The tests of last commit shows a pending problem:

how to calculate the base_url of "scopes" in importmap?

This indeed sounds like a bug, we should fix it by following spec proposal. I've written import map support last year and since it hasn't received much attention. Can you take a stab at fixing this problem?

Please merge with latest master

[ry]

@futurist Thanks for this patch - sorry it never got merged. I'm closing this because it's stale.

In general we are not convinced that import maps really solve any problems and we're considering removing them entirely. This explains why this well-implemented patch was not reviewed - we're hesitating on any features related to import maps. I apologize for not communicating that.

In any case, the feature seems reasonable. I am open to adding this feature if you really want it. Just with the understanding that import-maps remains unstable and it could very likely get cut. Hit me up on discord if you want to talk about it.