lib/file: fix border-use-cases of String::basename

and add nitunit tests to improve documentation

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/lib/standard/file.nit b/lib/standard/file.nit
index b23e86c..9786f92 100644 (file)
--- a/lib/standard/file.nit
+++ b/lib/standard/file.nit
@@ -240,12 +240,24 @@ redef class String
        end
 
        # Extract the basename of a path and remove the extension
+       #
+       #     assert "/path/to/a_file.ext".basename(".ext")         == "a_file"
+       #     assert "path/to/a_file.ext".basename(".ext")          == "a_file"
+       #     assert "path/to".basename(".ext")                     == "to"
+       #     assert "path/to/".basename(".ext")                    == "to"
+       #     assert "path".basename("")                        == "path"
+       #     assert "/path".basename("")                       == "path"
+       #     assert "/".basename("")                           == "/"
+       #     assert "".basename("")                            == ""
        fun basename(ext: String): String
        do
-               var pos = last_index_of_from('/', _length - 1)
+               var l = _length - 1 # Index of the last char
+               while l > 0 and self.chars[l] == '/' do l -= 1 # remove all trailing `/`
+               if l == 0 then return "/"
+               var pos = last_index_of_from('/', l)
                var n = self
                if pos >= 0 then
-                       n = substring_from(pos+1)
+                       n = substring(pos+1, l-pos)
                end
                return n.strip_extension(ext)
        end