Epic: Overrides Support

[darcyclarke]

Problem statement

Users want the ability to override/dependencies as they are being resolved.

Features

• a user is able to define a set of overrides in package.json that will resolve dependencies differently at specific points in the tree

Exit criteria

• RFC doc is accepted
• feature-set is fully implemented/functioning
  • overrides propagate through tree at load
  • edges are marked invalid if override is not met
  • removing a node removes its overrides
  • adding overrides to a node copies them to all of its edgesOut
  • nodeFromEdge in build-ideal-tree takes overrides into account
  • CanPlaceDep/PlaceDep verify that placing nodes does not violate overrides
• tests are written for coverage of this feature-set
• documentation has been updated for package.json (ie. adding a section specifically for overrides)

Useful Links

• RFC

[Haprog]

I think the RFC link in the description can be updated to https://github.com/npm/rfcs/blob/latest/accepted/0036-overrides.md (as the RFC PR has now been closed and moved to accepted).

[fernandopasik]

Any chance this will go any time soon into the https://github.com/npm/roadmap/projects/1 ?

[darcyclarke]

For historical reference: #377

[Haprog]

Thanks a lot to everybody involved for making this happen!

[piotr-cz]

This is included in npm v8.3.0 (2021-12-09)