Return uncolored for malformed LS_COLORS

We could try to patch up the empty case as shown in the issue, but I
think it is better to just bail and give up coloring if something seems
wrong. I decided not to issue a warning for this case, if it comes up
again we can think about adding one.

Fixes #135

NEWS.md

@@ -1,3 +1,8 @@
+# Development
+
+* `colourise_fs_path()` now returns paths uncolored if the colors argument /
+  `LS_COLORS` is malformed (#135).
+
 # fs 1.2.6
 
 * This is a small bugfix only release.

R/fs_path.R

@@ -112,6 +112,14 @@ colourise_fs_path <- function(x, ..., colors = Sys.getenv("LS_COLORS", gnu_ls_de
 
   vals <- strsplit(colors, ":")[[1]]
   nms <- strsplit(vals, "=")
+
+  if (!(
+      length(vals) == length(nms) &&
+      all(lengths(nms) == 2)
+      )) {
+    return(x)
+  }
+
   map <- setNames(
     vapply(nms, `[[`, character(1), 2),
     vapply(nms, `[[`, character(1), 1))

R/utils.R

@@ -121,3 +121,7 @@ assert <- function(msg, ..., class = "invalid_argument") {
 fs_error <- function(msg, class = "invalid_argument") {
   structure(class = c(class, "fs_error", "error", "condition"), list(message = msg))
 }
+
+lengths <- function(x) {
+  vapply(x, length, integer(1))
+}

tests/testthat/test-fs_path.R

@@ -53,6 +53,13 @@ describe("colourise_fs_path", {
       expect_equal(colourise_fs_path("file.Rmd"), "\033[32mfile.Rmd\033[0m")
     })
   })
+
+  it ("returns uncolored result if LS_COLORS is malformed", {
+    # This has an empty leading :
+    withr::local_envvar(c("LS_COLORS" = ":di=1;38;5;39:ex=1;38;5;34:ln=1;38;5;45:*.py=1;38;5;220:*.pdf=1;38;5;202:*.tex=1;38;5;196"))
+
+    expect_equal(colourise_fs_path("foo"), "foo")
+  })
 })
 
 describe("multicol", {