Honor create option in opener (#170)

* Honor `create` option in opener

Ported fix from fs.sshfs

All credit to @althonos

althonos/fs.sshfs@48664f2

* Switch to CreateFailed.catch_all decorator as suggested

Author: geoffjukes

fs/opener/ftpfs.py

@@ -6,9 +6,12 @@
 from __future__ import print_function
 from __future__ import unicode_literals
 
+import six
+
 import typing
 
 from .base import Opener
+from ..errors import FSError, CreateFailed
 
 if False:  # typing.TYPE_CHECKING
     from typing import List, Text, Union
@@ -23,6 +26,7 @@ class FTPOpener(Opener):
 
     protocols = ['ftp']
 
+    @CreateFailed.catch_all
     def open_fs(self,
                 fs_url,         # type: Text
                 parse_result,   # type: ParseResult
@@ -44,5 +48,8 @@ def open_fs(self,
             proxy=parse_result.params.get('proxy')
         )
         if dir_path:
+            if create:
+                ftp_fs.makedirs(dir_path, recreate=True)
             return ftp_fs.opendir(dir_path, factory=ClosingSubFS)
-        return ftp_fs
+        else:
+            return ftp_fs

tests/test_ftpfs.py

@@ -164,6 +164,34 @@ def test_opener_path(self):
         self.assertEqual(ftp_fs.gettext('bar'), 'baz')
         ftp_fs.close()
 
+    def test_create(self):
+
+        directory = os.path.join("home", self.user, "test", "directory")
+        base = 'ftp://user:1234@{}:{}/foo'.format(self.server.host, self.server.port)
+        url = "{}/{}".format(base, directory)
+
+        # Make sure unexisting directory raises `CreateFailed`
+        with self.assertRaises(errors.CreateFailed):
+            ftp_fs = open_fs(url)
+
+        # Open with `create` and try touching a file
+        with open_fs(url, create=True) as ftp_fs:
+            ftp_fs.touch("foo")
+
+        # Open the base filesystem and check the subdirectory exists
+        with open_fs(base) as ftp_fs:
+            self.assertTrue(ftp_fs.isdir(directory))
+            self.assertTrue(ftp_fs.isfile(os.path.join(directory, "foo")))
+
+        # Open without `create` and check the file exists
+        with open_fs(url) as ftp_fs:
+            self.assertTrue(ftp_fs.isfile("foo"))
+
+        # Open with create and check this does fail
+        with open_fs(url, create=True) as ftp_fs:
+            self.assertTrue(ftp_fs.isfile("foo"))
+
+
 class TestFTPFSNoMLSD(TestFTPFS):
 
     def make_fs(self):
@@ -174,3 +202,4 @@ def make_fs(self):
 
     def test_features(self):
         pass
+