Use DESCRIPTION instead of dependencies.R

[kamilzyla]

Currently we use implicit renv snapshots with dependencies.R + .renvignore to achieve a similar effect to explicit snapshots with a DESCRIPTION file. Explicit snapshots would be a more natural and preferable approach, but the seemed not to work in deployment to RSConnect when box was used. It might possible to use them after all - see research below.

Research by Jakub

Initial tests: both renv and packrat read it out of the box.

renv works with a DESCRIPTIOPN file that includes only Imports section. packrat requires also Package.

Need to be tested with RSConnect Deployment.

Note: DESCRIPTION can be manipulated using desc package.

[kamilzyla]

The PR #230 offers a complete implementation for this feature, but we decided to postpone it as the solution has some side effects which need to be considered. A project with a DESCRIPTION containing Package: line is treated as an R package by renv. It then puts the library outside the project which can cause issues when trying to run rhino::init() for the second time in the same directory. It might also break CI caching (fixable) and seems less desirable in general (libraries left behind after a project, how do I purge a library).

Possible solutions:

1. Keep the library in the project with RENV_PATHS_LIBRARY.
2. Remove the library before init().
3. Pick the “2. Re-initialize” option during init().
4. Initialize bare.