address @efiop's suggestions

dvc/remote/s3.py

@@ -213,11 +213,11 @@ class RemoteS3(RemoteBASE):
         return path_info.path == fname or fname.startswith(dir_path.path)
 
     def makedirs(self, path_info):
-        # We need to support creating empty directories, on S3, that means
+        # We need to support creating empty directories, which means
         # creating an object with an empty body and a trailing slash `/`.
         #
         # We are not creating directory objects for every parent prefix,
-        # it doesn't make sense.
+        # as it is not required.
         dir_path = path_info / ""
         self.s3.put_object(Bucket=path_info.bucket, Key=dir_path.path, Body="")
 

tests/unit/remote/test_s3.py

@@ -103,8 +103,8 @@ def test_copy_preserve_etag_across_buckets(remote):
     assert from_etag == to_etag
 
 
-def makedirs(remote):
-    empty_dir = remote.path_info / "empty_dir"
+def test_makedirs(remote):
+    empty_dir = remote.path_info / "empty_dir" / ""
     remote.remove(empty_dir)
     assert not remote.exists(empty_dir)
     remote.makedirs(empty_dir)