Fix Path.explode

src/path.ml

@@ -411,13 +411,17 @@ let split_first_component t =
     None
 
 let explode t =
-  if is_local t then
+  if is_root t then
+    Some []
+  else if is_local t then
     Some (String.split t ~on:'/')
   else
     None
 
 let explode_exn t =
-  if is_local t then
+  if is_root t then
+    []
+  else if is_local t then
     String.split t ~on:'/'
   else
     Sexp.code_error "Path.explode_exn" ["path", Atom t]

test/unit-tests/path.mlt

@@ -47,3 +47,23 @@ Path.(descendant (r "foo") ~of_:Path.root)
 [%%expect{|
 - : Jbuilder.Path.t option = Some foo
 |}]
+
+Path.explode (Path.of_string "a/b/c");
+[%%expect{|
+- : string list option = Some ["a"; "b"; "c"]
+|}]
+
+Path.explode (Path.of_string "a/b");
+[%%expect{|
+- : string list option = Some ["a"; "b"]
+|}]
+
+Path.explode (Path.of_string "a");
+[%%expect{|
+- : string list option = Some ["a"]
+|}]
+
+Path.explode (Path.of_string "");
+[%%expect{|
+- : string list option = Some []
+|}]