[R-pkg-devel] CRAN policies with regards to runnable examples

[Jim Hester]

CRAN reviewers have somewhat recently been requesting that new
submissions have runnable examples. This is in general a good
recommendation, but the reviewers seem to apply this policy
unconditionally, and there are certain classes of packages where this
is either extremely cumbersome or impossible to do.

Two in particular are packages which wrap web APIs and packages
containing shiny applications. Even the most robust APIs will
inevitably have network failures, causing spurious failures on CRAN's
machines, and often the APIs require credentials to access, which
won't be available on the build machines. Shiny applications block the
R process and require user interaction in a browser to function, they
cannot really be run non-interactively.

In these cases it seems appropriate to put examples in a `\dontrun{}`
or `\donttest{}` block, and this is what is suggested by writing R
extensions. However CRAN reviewers have refused to accept packages
taking this approach.

If these workarounds are not acceptable what _does_ CRAN want package
authors to do in these cases?

Jim