Treat `new URL('relativePathHere', import.meta.url)` as assets.

[Jack-Works]

Suggestion

When using a file in TypeScript, new URL("./file.png", import.meta.url), TypeScript should copy this file to the output folder, like what it did for importing JSON files.

🔍 Search Terms

new URL import meta url

✅ Viability Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

📃 Motivating Example

This is useful when writing a library with assets referenced otherwise we need extra steps to copy those files.

[nmain]

https://github.com/Microsoft/TypeScript/wiki/TypeScript-Design-Goals

Non-goals
Provide an end-to-end build pipeline. Instead, make the system extensible so that external tools can use the compiler for more complex build workflows.

[Jack-Works]

https://github.com/Microsoft/TypeScript/wiki/TypeScript-Design-Goals

Non-goals
Provide an end-to-end build pipeline. Instead, make the system extensible so that external tools can use the compiler for more complex build workflows.

But why it can copy JSON files with resolveJsonModule? And I belive they'll also do this for wasm files (#39784)

[andrewbranch]

How are we supposed to know that URL is special? It’s just a constructor defined in a lib file.

[Jack-Works]

How are we supposed to know that URL is special? It’s just a constructor defined in a lib file.

It's hard coded in all of the toolchains like how they treat require.

[andrewbranch]

Therein lies the answer to

But why it can copy JSON files with resolveJsonModule?

[Jack-Works]

Therein lies the answer to

But why it can copy JSON files with resolveJsonModule?

Because in resolveJsonModule, TypeScript actually parse and generate type information for JSON module right

[andrewbranch]

Yes, and more generally, we have to process imports and exports in order for modules to work, and there is unambiguous syntax, not dependent on type definitions, that triggers an import.

[Jack-Works]

What if we have this import reflection proposal in the ECMAScript? Can TypeScript copy the asset for the following code? (tc39/proposal-source-phase-imports#16 (comment))

import u from './x.png' as 'asset-reference'
await readFile(u)