Deno 2.0: BYONM should only be enabled when root folder has package.json

[marvinhagemeister]

For some reason it seems like having a package.json in a different workspace member affects resolution in a workspace member that doesn't have one. In this case the "Could not find matching package in package.json file" error is thrown in a workspace member that has no package.json.

Steps to reproduce

1. Clone https://github.com/zemili-group/moonrepoV3
2. Run cd apps/zemili/backend/
3. Run deno task dev

Output:

error: Could not find a matching package for 'npm:path-to-regexp@6.2.1' in a package.json file. You must specify this as a package.json dependency when the node_modules folder is not managed by Deno.
    at https://jsr.io/@oak/oak/16.1.0/deps.ts:87:8

Version: Deno 2.0.0-rc.0+42cf762

[bartlomieju]

Duplicate #23267

[marvinhagemeister]

Reopening, because this issue is not a duplicate of #23267 . That one isn't about workspaces but this one is.

[dsherret]

We should only enable byonm when the root workspace folder has a package.json.

The reason is so that adding a new workspace member that has a package.json doesn't change the behaviour.