fix for superfluous directory

Makefile

@@ -8,7 +8,7 @@ release: readme
 
 .PHONY: test
 test:
-	nosetests --with-coverage --cover-erase --cover-package=fs_s3fs fs_s3fs/tests
+	nosetests --with-coverage --cover-erase --cover-package=fs_s3fs -a "!slow" fs_s3fs/tests
 	rm .coverage
 
 .PHONY: testall

docs/index.rst

@@ -93,8 +93,7 @@ URL from an S3 object. Here's an example:
 More Information
 ================
 
-See the `PyFilesystem Docs <https://docs.pyfilesystem.org>`_ for full
-details.
+See the `PyFilesystem Docs <https://docs.pyfilesystem.org>`_ for documentation on the rest of the PyFilesystem interface.
 
 
 Indices and tables

fs_s3fs/_s3fs.py

@@ -295,7 +295,7 @@ def _path_to_key(self, path):
         _key = "{}/{}".format(
             self._prefix,
             _path
-        ).replace('/', self.delimiter)
+        ).lstrip('/').replace('/', self.delimiter)
         return _key
 
     def _path_to_dir_key(self, path):
@@ -304,7 +304,7 @@ def _path_to_dir_key(self, path):
         _key = forcedir("{}/{}".format(
             self._prefix,
             _path
-        )).replace('/', self.delimiter)
+        )).lstrip('/').replace('/', self.delimiter)
         return _key
 
     def _key_to_path(self, key):

fs_s3fs/tests/test_s3fs.py

@@ -2,13 +2,37 @@
 
 import unittest
 
+from nose.plugins.attrib import attr
+
 from fs.test import FSTestCases
 
 from fs_s3fs import S3FS
 
 import boto3
 
 
+class TestS3FS(FSTestCases, unittest.TestCase):
+    """Test S3FS implementation from dir_path."""
+    bucket_name = 'fsexample'
+    s3 = boto3.resource('s3')
+    client = boto3.client('s3')
+
+    def make_fs(self):
+        self._delete_bucket_contents()
+        return S3FS(self.bucket_name)
+
+    def _delete_bucket_contents(self):
+        response = self.client.list_objects(
+            Bucket=self.bucket_name
+        )
+        contents = response.get("Contents", ())
+        for obj in contents:
+            self.client.delete_object(
+                Bucket=self.bucket_name,
+                Key=obj["Key"]
+            )
+
+@attr('slow')
 class TestS3FSSubDir(FSTestCases, unittest.TestCase):
     """Test S3FS implementation from dir_path."""
     bucket_name = 'fsexample'
@@ -30,3 +54,17 @@ def _delete_bucket_contents(self):
                 Bucket=self.bucket_name,
                 Key=obj["Key"]
             )
+
+
+class TestS3FSHelpers(unittest.TestCase):
+
+    def test_path_to_key(self):
+        s3 = S3FS('foo')
+        self.assertEqual(s3._path_to_key('foo.bar'), 'foo.bar')
+        self.assertEqual(s3._path_to_key('foo/bar'), 'foo/bar')
+
+    def test_path_to_key_subdir(self):
+        s3 = S3FS('foo', '/dir')
+        self.assertEqual(s3._path_to_key('foo.bar'), 'dir/foo.bar')
+        self.assertEqual(s3._path_to_key('foo/bar'), 'dir/foo/bar')
+