Folder structure is not being preserved in `unbundle` mode

[Thao-Tran]

Reproduction link or steps

Opened #817 with a failing test case as an example.

What is expected?

With the folder structure of the following

src
  |- utils
    |- bar.ts

and the option entry: 'src/**/*.ts' and unbundle: true, the output directory should be

dist
  |- utils
    |- bar.ts

What is actually happening?

The output directory is

dist
 |- bar.ts

Any additional comments?

I currently have a workaround where entry: { '*': 'src/**/*.ts'} gives the expected output structure, but it'd be nice if this can be part of the main unbundle functionality.

[sxzz]

Our current strategy is to determine the project's root directory by using the maximum common path.

We need to know where your root directory is located; we cannot detect it using only a single wildcard.

[sxzz]

This has been fixed by adding a new root option. You can now explicitly set the root directory to control the output structure:

import { defineConfig } from 'tsdown'

export default defineConfig({
  entry: 'src/**/*.ts',
  unbundle: true,
  root: '.', // preserves the `src/` prefix in output
})

Or via CLI:

tsdown --unbundle --root .

By default, root is computed as the common base directory of all entry files (in your case src/), which is why the directory structure was being flattened. Setting root: '.' makes the output preserve the full path relative to the project root.

[Thao-Tran]

@sxzz That makes sense, thanks for the quick fix!