How do I use my own import map while vendoring?

[jimisaacs]

As far as I can tell, there's only one import map allowed as input in every command.

Would if you could pass --import-map to deno vendor, so that the generated import map output is merged the one specified as input?

[jimisaacs]

It would be nice if it did this, but also walked the input import map to still vendor remote modules specified in the input import map. Though the entries of the input import map remain unchanged, though still merged with the generated import map.

This means that if the input import map just so happened to specify every remote module it could, then the final generated import map would look the same as the source one.

[jimisaacs]

I actually didn't try it until just now, I think this is what it does

Edit: See followup

[jimisaacs]

I might have spoke too soon.

I have this import map at src/import_map.json:

{
  "imports": {
    "oak": "https://deno.land/x/[email protected]/mod.ts",
    "react": "https://esm.sh/react@18",
    "react-dom/server": "https://esm.sh/react-dom@18/server"
  }
}

and deno vendor main.ts --import_map=src/import_map.json generated this:

{
  "imports": {
    "https://cdn.esm.sh/": "./cdn.esm.sh/",
    "https://deno.land/": "./deno.land/",
    "https://esm.sh/": "./esm.sh/",
    "https://raw.githubusercontent.com/": "./raw.githubusercontent.com/"
  },
  "scopes": {
    "./cdn.esm.sh/": {
      "/v78/[email protected]/deno/react.js": "./cdn.esm.sh/v78/[email protected]/deno/react.js"
    },
    "./deno.land/": {
      "oak": "./deno.land/x/[email protected]/mod.ts"
    },
    "./esm.sh/": {
      "react": "./esm.sh/[email protected]",
      "react-dom/server": "./esm.sh/react-dom@18/server.js"
    }
  }
}

Then when I run:

deno run --allow-net --allow-read --import-map ./vendor/import_map.json --cached-only main.ts

I get:

...
error: Relative import path "oak" not prefixed with / or ./ or ../ and not in import map from ...
...

[jimisaacs]

Ok, from the previous example, I would expect the generated import_map.json to look like this, which works:

{
  "imports": {
    "oak": "https://deno.land/x/[email protected]/mod.ts",
    "react": "https://esm.sh/react@18",
    "react-dom/server": "https://esm.sh/react-dom@18/server",
    "https://cdn.esm.sh/": "./cdn.esm.sh/",
    "https://deno.land/": "./deno.land/",
    "https://esm.sh/": "./esm.sh/",
    "https://raw.githubusercontent.com/": "./raw.githubusercontent.com/"
  },
  "scopes": {
    "./cdn.esm.sh/": {
      "/v78/[email protected]/deno/react.js": "./cdn.esm.sh/v78/[email protected]/deno/react.js"
    }
  }
}

This feels like it could be a pretty straight forward transformation to be honest. It just keeps the existing mappings from the source input map, and resolves and adds to it to keep it local, as if the value of those mappings were what are actually used in source.

[jimisaacs]

Found #13697, so this feels like a dupe

[jimisaacs]

Hmm, seems my last throught is broken with --no-remote, which seems odd. I guess it makes sense if it is determining whether to to continue based on the shape of the strings in the imports section, versus how they resolve with an import_map 🤔

[jimisaacs]

still it's close, as I think it might just need to walk the vendor generated map to get a the value starting with the origin.

[jimisaacs]

I ended up writing this for now:
https://github.com/jimisaacs/source_vendor_import_map_fix_up

[dsherret]

This is essentially #13697. Follow there for updates.