Document changes

Author: klmr

NEWS.md

@@ -74,6 +74,9 @@
 * Added check for `.lintr` configuration file in the `.github/linters` project sub folder. This is to improve 
   compatibility with Super-Linter(#1746, @tonyk7440)
 
+* The {lintr} configuration file is now searched in the system's user configuration path; the lintr config filename can
+  also be configured explicitly by setting the environment variable `R_LINTR_LINTER_FILE` (#460, @klmr)
+
 ### New linters
 
 * `unnecessary_lambda_linter()`: detect unnecessary lambdas (anonymous functions), e.g.

vignettes/lintr.Rmd

@@ -91,11 +91,12 @@ exclusions: list(
 More generally, `lintr` searches for a settings file according to following prioritized list.
 The first one found, if any, will be used.
 
-1.  If `options(lintr.linter_file)` is an absolute path, this file will be used. The default for this option is `".lintr"`.
+1.  If `options(lintr.linter_file)` is an absolute path, this file will be used. The default for this option is `".lintr"` or the value of the environment variable `R_LINTR_LINTER_FILE`, if set.
 2.  A linter file (that is a file named like `lintr.linter_file`) in the currently searched directory, i.e. the directory of the file passed to `lint()`. When run from `lint_package()`, this directory can differ for each linted file.
 3.  A linter file in a parent directory of the currently-searched directory, starting from the deepest path, moving upwards one level at a time.
 4.  A linter file in the user's `HOME` directory.
 5.  A linter file in the `.github/linters` child directory of the currently-search directory.
+6.  A linter file called `config` in the user's configuration path (given by `tools::R_user_dir("lintr", which = "config")`).
 
 If no linter file is found, only default settings take effect (see [defaults](#defaults)).