Unable to import types in v6

[monken]

Bug Description

import type { NonNormalizedSpec } from 'vega-lite/build/src/spec';

Pre v6, I was able to import types like NonNormalizedSpec from the spec file. Since v6 (and the switch to ESM), I'm no longer able to reach these types. It would be great if the spec file could get exposed as a module again so that I can migrate to v6.

[domoritz]

Ahh, I see. Thanks for reporting. To explain, since we added explicit exports, you can't import arbitrary files anymore. There is a hack to expose every file but it's problematic since we don't want to expose all internals as public API. We could still do it but they wouldn't be stable API.

How do you suggest we expose the types? We could expose specific types but I would still want to mark them as not stable.

[monken]

I think it would be sufficient to add the https://github.com/vega/vega-lite/blob/main/src/spec/index.ts file to the exports in package.json.

https://github.com/vega/vega-lite/blob/main/package.json#L27

[domoritz]

Okay. Do you have an idea how we can mark it as exported yet unstable?

[domoritz]

Fixed in #9584. I need a careful review of the changes I made there.

[monken]

vega-lite/types_unstable is a great compromise.