EmberData | Deprecate Legacy Imports

Summary

Deprecates import DS from "ember-data"; and individual imports within the ember-data package in favor of the imports provided by RFC#395 packages

Motivation

These imports are just a legacy remnant we no longer need.

Detailed design

Lint rules and a codemod already exist to migrate users to using packages, and have been available now for over a year.

The ember-data-packages plugin for ember-cli-babel would be updated so that users would receive a deprecation when importing from the legacy paths. If required for legacy global or DS import a runtime deprecation would be added as well.

To resolve, users would need only to run the codemod to convert to using packages.

The deprecation would target 5.0 and would become enabled no-sooner than 4.1 (although it may be made available before then).

How we teach this

Users have already been encouraged to migrate, documentation has already been updated to reflect the package based imports, and lint rules and codemods already exist. Deprecating and removal at this point is just a formality as the last stage of fading out the old world.

Drawbacks

Someone somewhere probably is doing something bad.

Alternatives

Leave them to waste away.