support importing/exporting .d.ts files

[pi0]

🐛 The bug
What isn't working? Describe what the bug is.

🛠️ To reproduce

• Create src/types.d.ts
• Inside src/index.ts:

export * from './types'

siroc build:

[UNRESOLVED_IMPORT] Could not resolve './types' from src/index.ts

🌈 Expected behaviour

Types exportable from .d.ts files

ℹ️ Additional context

We can fix this issue by renaming types to types.ts or using export type {} from './types' (with .d.ts). Downside of first is that it is not semantic and types are not usable in typescript config and for second, when there are lots of types, named exports are hard. BTW not sure even this is something fixable by siroc but tought mentioning if there is a workaround.

[danielroe]

Interesting question. I'm not sure we should be able to import/export dts files. I think we should always be operating with .ts files and generating the dts files in the build stage.

[danielroe]

https://devblogs.microsoft.com/typescript/announcing-typescript-4-2/#d-ts-extensions-cannot-be-used-in-import-paths

[pi0]

@danielroe of course we should never include .d.ts in import path to match runtime. Issue is that with siroc we cannot export from .d.ts files even when there is no extension in import path and forced to use .ts :)

Interesting question. I'm not sure we should be able to import/export dts files. I think we should always be operating with .ts files and generating the dts files in the build stage.

This is not always best option. src/dts files are can be usable for linked demo and tests in their tsconfig. Otherwise we need to force a dry build step or add duplicate shims