feat: Check all subdirs in find_root() instead of only the first existing one

R/root.R

@@ -90,45 +90,65 @@ print.root_criterion <- function(x, ...) {
 #' @export
 find_root <- function(criterion, path = ".") {
   criterion <- as_root_criterion(criterion)
+  path <- normalizePath(path, winslash = "/", mustWork = TRUE)
+  start_paths <- path[dir.exists(path)]
 
-  start_path <- get_start_path(path, criterion$subdir)
-  path <- start_path
-
-  for (i in seq_len(.MAX_DEPTH)) {
-    for (f in criterion$testfun) {
-      if (f(path)) {
-        return(path)
-      }
+  if (length(criterion$subdir) > 0L) {
+    sub_paths <- file.path(path, criterion$subdir)
+    sub_paths <- sub_paths[dir.exists(sub_paths)]
+    if (length(sub_paths) > 0L) {
+      start_paths <- sub_paths
     }
+  }
 
-    if (is_fs_root(path)) {
-      stop("No root directory found in ", start_path, " or its parent directories. ",
-        paste(format(criterion), collapse = "\n"),
-        call. = FALSE
-      )
-    }
+  root <- NULL
+  max_depth_reached <- FALSE
+  max_depth_path <- NULL
 
-    path <- dirname(path)
-  }
+  for (start_path in start_paths) {
+    cur_path <- start_path
 
-  stop("Maximum search of ", .MAX_DEPTH, " exceeded. Last path: ", path, call. = FALSE)
-}
+    for (i in seq_len(.MAX_DEPTH)) {
+      for (fn in criterion$testfun) {
+        if (fn(cur_path)) {
+          root <- cur_path
+          break
+        }
+      }
 
-.MAX_DEPTH <- 100L
+      if (length(root) > 0L || is_fs_root(cur_path)) {
+        break
+      }
 
-get_start_path <- function(path, subdirs) {
-  path <- normalizePath(path, winslash = "/", mustWork = TRUE)
+      if (i == .MAX_DEPTH) {
+        max_depth_reached <- TRUE
+        max_depth_path <- cur_path
+      }
+
+      cur_path <- dirname(cur_path)
+    }
 
-  for (subdir in subdirs) {
-    subdir_path <- file.path(path, subdir)
-    if (dir.exists(subdir_path)) {
-      return(subdir_path)
+    if (length(root) > 0L) {
+      break
     }
   }
 
-  path
+  if (length(root) > 0L) {
+    return(root)
+  }
+
+  if (max_depth_reached) {
+    stop("Maximum search of ", .MAX_DEPTH, " exceeded. Last path: ", max_depth_path, call. = FALSE)
+  }
+
+  stop("No root directory found in ", paste0(start_paths, collapse = ", "), " or ", ifelse(length(start_paths) > 1L, "their", "its"), " parent directories. ",
+       paste(format(criterion), collapse = "\n"),
+       call. = FALSE
+  )
 }
 
+.MAX_DEPTH <- 100L
+
 # Borrowed from devtools
 is_fs_root <- function(path) {
   identical(

tests/testthat/test-root.R

@@ -297,3 +297,32 @@ test_that("stops if depth reached", {
   # Checks that search for root terminates for very deep hierarchies
   expect_error(find_root_mocked(""), "Maximum search of [0-9]+ exceeded")
 })
+
+test_that("all criterion subdirs are checked", {
+  wd <- normalizePath(getwd(), winslash = "/")
+  criterion <- root_criterion(
+    testfun = function(path) file.exists(file.path(path, "target")) && basename(dirname(dirname(path))) == "check_subdirs",
+    desc = "has file `target` and basename of grandparent dir is `check_subdirs`",
+    subdir = c("a", "b")
+  )
+
+  expect_equal(
+    find_root(criterion, "check_subdirs/1"),
+    file.path(wd, "check_subdirs/1/a")
+  )
+
+  expect_equal(
+    find_root(criterion, "check_subdirs/2"),
+    file.path(wd, "check_subdirs/2/b")
+  )
+
+  expect_error(
+    find_root(criterion, "check_subdirs/3"),
+    "No root directory found"
+  )
+
+  expect_error(
+    find_root(criterion, "check_subdirs/4"),
+    "No root directory found"
+  )
+})