move `_format.ts` into root

[scarf005]

Is your feature request related to a problem? Please describe.

followup of https://github.com/denoland/deno_std/pull/3886#issuecomment-1835302006. currently assert/_format.ts and expect/_format.ts is identical but duplicated across modules.

Describe the solution you'd like

create private top-level module, _format.ts and _format_test.ts

Describe alternatives you've considered

• symlinks would probably not work on web.
• keep the status quo, however this increases cognitive complexity and makes it harder to sync both files.

[iuioiua]

Agreed. For context, we're in the process of preparing the Standard Library to be compatible with Deno's workspaces functionality. We had to copy this file as workspaces don't yet support internal utilities across sub-modules.

Either way, let's keep this open for when it does.

References:

• https://github.com/denoland/deno_std/issues/3880
• https://github.com/denoland/deno_std/pull/3884

[scarf005]

thanks for the context. should I open a draft PR, just in case?

[iuioiua]

Ah, perhaps not yet. @lucacasonato, could you please update this issue once the suggested functionality is supported?