For #1026. Update repair_path() to work with network paths, add test.

R/utils.R

@@ -128,8 +128,9 @@ repair_path <- function(path) {
   }
   path <- path.expand(path)
   path <- gsub("\\\\", "/", path)
-  # WSL cmdstan path is a network path and needs the leading //
-  path <- gsub("//(?!wsl)", "/", path, perl = TRUE)
+  # Network paths (such as the cmdstan path on WSL) need the leading //
+  # https://github.com/stan-dev/cmdstanr/issues/1026
+  path <- gsub("(?<!^)//", "/", path, perl = TRUE)
   # remove trailing "/"
   path <- gsub("/$","", path)
   path

tests/testthat/test-utils.R

@@ -143,6 +143,8 @@ test_that("cmdstan_diagnose works if bin/diagnose deleted file", {
 test_that("repair_path() fixes slashes", {
   # all slashes should be single "/", and no trailing slash
   expect_equal(repair_path("a//b\\c/"), "a/b/c")
+  # but leading double slash is needed for UNC paths on  (e.g. the cmdstan path on WSL)
+  expect_equal(repair_path("\\\\wsl//my-project//"), "//wsl/my-project")
 })
 
 test_that("repair_path works with zero length path or non-string path", {