Fix absolutePath to correctly handle absolute paths

R/utils.R

@@ -293,6 +293,18 @@ dirRemove <- function(path) {
 # difference is that a canonical path follows symlinks and doesn't have any
 # `..`, while an absolute path here is simply one that starts with `/`.
 absolutePath <- function(path) {
+  if (!is.character(path) || length(path) != 1 || path == "") {
+    stop("path must be a single non-empty string.")
+  }
+  if (substr(path, 1, 1) == "/") {
+    return(path)
+  }
+  if (isWindows()) {
+    # C:/abcd or c:\abcd
+    if (grepl("^[A-Za-z]:[/\\]", path)) {
+      return(path)
+    }
+  }
   norm_path <- normalizePath(path, mustWork = FALSE)
   if (path == norm_path) {
     file.path(getwd(), path)
@@ -1711,14 +1723,14 @@ createVarPromiseDomain <- function(env, name, value) {
   force(env)
   force(name)
   force(value)
-  
+
   promises::new_promise_domain(
     wrapOnFulfilled = function(onFulfilled) {
       function(...) {
         orig <- env[[name]]
         env[[name]] <- value
         on.exit(env[[name]] <- orig)
-        
+
         onFulfilled(...)
       }
     },
@@ -1727,7 +1739,7 @@ createVarPromiseDomain <- function(env, name, value) {
         orig <- env[[name]]
         env[[name]] <- value
         on.exit(env[[name]] <- orig)
-        
+
         onRejected(...)
       }
     },
@@ -1739,4 +1751,4 @@ createVarPromiseDomain <- function(env, name, value) {
       force(expr)
     }
   )
-}
+}

tests/testthat/test-utils.R

@@ -191,3 +191,44 @@ test_that("Callbacks fire in predictable order", {
   cb$invoke()
   expect_equal(x, c(1, 2, 3))
 })
+
+
+test_that("absolutePath works as expected", {
+  # Relative paths that don't exist
+  expect_identical(absolutePath("foo9484"), file.path(getwd(), "foo9484"))
+  expect_identical(absolutePath("foo9484/bar"), file.path(getwd(), "foo9484/bar"))
+
+  # Absolute path that exists and does NOT have a symlink
+  expect_identical(absolutePath("/"), "/")
+  # Find a path that is not a symlink and test it.
+  # Use paste0 instead of file.path("/", ...) or dir(full.names=T) because
+  # those can result in two leading slashes.
+  paths <- paste0("/", dir("/"))
+  symlink_idx <- (Sys.readlink(paths) != "")
+  paths <- paths[!symlink_idx]
+  if (length(paths) != 0) {
+    test_path <- paths[1]
+    expect_identical(absolutePath(test_path), test_path)
+  }
+
+  # On Windows, absolute paths can start with a drive letter.
+  if (isWindows()) {
+    expect_identical(absolutePath("z:/foo9484"), "z:/foo9484")
+    expect_identical(absolutePath("c:\\foo9484"), "c:\\foo9484")
+    expect_identical(absolutePath("d:\\"), "d:\\")
+    expect_identical(absolutePath("d:/"), "d:/")
+  }
+
+  # Absolute path that doesn't exist
+  expect_identical(absolutePath("/foo9484"), "/foo9484")
+  expect_identical(absolutePath("/foo9484/bar"), "/foo9484/bar")
+
+  # Invalid input
+  expect_error(absolutePath(NULL))
+  expect_error(absolutePath(NA))
+  expect_error(absolutePath(character(0)))
+  expect_error(absolutePath(""))
+  expect_error(absolutePath(12))
+  expect_error(absolutePath(c("a", "b")))
+  expect_error(absolutePath(list("abc")))
+})