Feature: context-sensitive lintr configuration

[russHyde]

lintr can be used in several settings: precommit, CI, interactively etc

I found that when using lintr in precommit, object-usage was throwing a lot of false positives. This arose because only the commit set gets linted, so if you are lint()ing a file that refers to an object defined elsewhere in the package, lintr assumes that object doesn't exist.

In CI, I can load the package prior to linting it - taking care of any object-usage lints.
But I can't easily load the package in precommit because that would require adding all my package's dependencies to the env where the lintr hook runs.

So I was wondering whether there is a way to conditionally specify whether a linter is active, e.g. based on environment variables:

# .lintr
linters: linters_with_defaults(
    object_usage_linter = if (Sys.getenv("THIS_IS_A_CI_RUN")) object_usage_linter() else NULL,
   ...snip ...
)

Is there a neater way to encode conditions under which the configured linters should run?

[russHyde]

Original thread (on {precommit}): lorenzwalthert/precommit#440

[MichaelChirico]

I think it's more natural to do the sort of if() branching you mentioned now that we support configs in plain R sources.

I suspect that closes this issue, leaving open for now for further comment.