Bugfix: Save cache in the requested directory (r-lib#213)

R/cache.R

@@ -1,6 +1,6 @@
 #' Clear the lintr cache
 #'
-#' @param file filename whose cache to clear.  If you pass \code{NULL} it will
+#' @param file filename whose cache to clear.  If you pass \code{NULL}, it will
 #' delete all of the caches.
 #' @param path directory to store caches.  Reads option 'lintr.cache_directory'
 #' as the default.

R/expect_lint.R

@@ -9,7 +9,7 @@
 #'   \item named-vector check if the lint's field matches the named field.
 #'   \item list-vectors check if the given lint matches (use if more than one lint is returned for the content)
 #' }
-#' @param ... one or more linters to use for the check
+#' @param ... arguments passed to \code{\link{lint}} including e.g. the linters or cache to use.
 #' @param file if not \code{NULL} read content from a file rather than from \code{content}
 expect_lint <- function(content, checks, ..., file = NULL) {
 

R/lint.R

@@ -15,8 +15,8 @@ NULL
 #' @param filename the given filename to lint.
 #' @param linters a list of linter functions to apply see \code{\link{linters}}
 #' for a full list of default and available linters.
-#' @param cache toggle caching of lint results, if passed a character vector
-#' uses that file as the cache.
+#' @param cache given a logical, toggle caching of lint results. If passed a
+#' character string, store the cache in this directory.
 #' @param ... additional arguments passed to \code{\link{exclude}}.
 #' @param parse_settings whether to try and parse the settings
 #' @export
@@ -96,7 +96,7 @@ lint <- function(filename, linters = NULL, cache = FALSE, ..., parse_settings =
 
   if (isTRUE(cache)) {
     cache_file(lint_cache, filename, linters, lints)
-    save_cache(lint_cache, filename)
+    save_cache(lint_cache, filename, cache_dir)
   }
 
   res <- exclude(lints, ...)

tests/testthat/test-cache.R

@@ -307,3 +307,15 @@ test_that("it returns the correct line if it is after the current line", {
 
   expect_equal(find_new_line(3, "test3", t1), 3)
 })
+
+
+test_that("lint() uses the provided cache directory", {
+  dir <- "temp_lintr_cache"
+  unlink(dir, recursive = TRUE)
+  expect_false(dir.exists(dir))
+  expect_lint("a <- 1", NULL, assignment_linter, cache=dir) # create the cache
+  expect_true(dir.exists(dir))
+  expect_lint("a <- 1", NULL, assignment_linter, cache=dir) # read the cache
+  expect_true(dir.exists(dir))
+  unlink(dir, recursive = TRUE)
+})