BUG: Don't allow ContentsManager to delete root.

Doing so leaves the notebook app in a bad state.

IPython/html/services/contents/manager.py

@@ -1,468 +1,471 b''
 """A base class for contents managers."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from fnmatch import fnmatch
 import itertools
 import json
 import os
 import re
 
 from tornado.web import HTTPError
 
 from .checkpoints import Checkpoints
 from IPython.config.configurable import LoggingConfigurable
 from IPython.nbformat import sign, validate, ValidationError
 from IPython.nbformat.v4 import new_notebook
 from IPython.utils.importstring import import_item
 from IPython.utils.traitlets import (
     Any,
     Dict,
     Instance,
     List,
     TraitError,
     Type,
     Unicode,
 )
 from IPython.utils.py3compat import string_types
 
 copy_pat = re.compile(r'\-Copy\d*\.')
 
 
 class ContentsManager(LoggingConfigurable):
     """Base class for serving files and directories.
 
     This serves any text or binary file,
     as well as directories,
     with special handling for JSON notebook documents.
 
     Most APIs take a path argument,
     which is always an API-style unicode path,
     and always refers to a directory.
 
     - unicode, not url-escaped
     - '/'-separated
     - leading and trailing '/' will be stripped
     - if unspecified, path defaults to '',
       indicating the root path.
 
     """
 
     notary = Instance(sign.NotebookNotary)
     def _notary_default(self):
         return sign.NotebookNotary(parent=self)
 
     hide_globs = List(Unicode, [
             u'__pycache__', '*.pyc', '*.pyo',
             '.DS_Store', '*.so', '*.dylib', '*~',
         ], config=True, help="""
         Glob patterns to hide in file and directory listings.
     """)
 
     untitled_notebook = Unicode("Untitled", config=True,
         help="The base name used when creating untitled notebooks."
     )
 
     untitled_file = Unicode("untitled", config=True,
         help="The base name used when creating untitled files."
     )
 
     untitled_directory = Unicode("Untitled Folder", config=True,
         help="The base name used when creating untitled directories."
     )
 
     pre_save_hook = Any(None, config=True,
         help="""Python callable or importstring thereof
 
         To be called on a contents model prior to save.
 
         This can be used to process the structure,
         such as removing notebook outputs or other side effects that
         should not be saved.
 
         It will be called as (all arguments passed by keyword)::
 
             hook(path=path, model=model, contents_manager=self)
 
         - model: the model to be saved. Includes file contents.
           Modifying this dict will affect the file that is stored.
         - path: the API path of the save destination
         - contents_manager: this ContentsManager instance
         """
     )
     def _pre_save_hook_changed(self, name, old, new):
         if new and isinstance(new, string_types):
             self.pre_save_hook = import_item(self.pre_save_hook)
         elif new:
             if not callable(new):
                 raise TraitError("pre_save_hook must be callable")
 
     def run_pre_save_hook(self, model, path, **kwargs):
         """Run the pre-save hook if defined, and log errors"""
         if self.pre_save_hook:
             try:
                 self.log.debug("Running pre-save hook on %s", path)
                 self.pre_save_hook(model=model, path=path, contents_manager=self, **kwargs)
             except Exception:
                 self.log.error("Pre-save hook failed on %s", path, exc_info=True)
 
     checkpoints_class = Type(Checkpoints, config=True)
     checkpoints = Instance(Checkpoints, config=True)
     checkpoints_kwargs = Dict(config=True)
 
     def _checkpoints_default(self):
         return self.checkpoints_class(**self.checkpoints_kwargs)
 
     def _checkpoints_kwargs_default(self):
         return dict(
             parent=self,
             log=self.log,
         )
 
     # ContentsManager API part 1: methods that must be
     # implemented in subclasses.
 
     def dir_exists(self, path):
         """Does the API-style path (directory) actually exist?
 
         Like os.path.isdir
 
         Override this method in subclasses.
 
         Parameters
         ----------
         path : string
             The path to check
 
         Returns
         -------
         exists : bool
             Whether the path does indeed exist.
         """
         raise NotImplementedError
 
     def is_hidden(self, path):
         """Does the API style path correspond to a hidden directory or file?
 
         Parameters
         ----------
         path : string
             The path to check. This is an API path (`/` separated,
             relative to root dir).
 
         Returns
         -------
         hidden : bool
             Whether the path is hidden.
 
         """
         raise NotImplementedError
 
     def file_exists(self, path=''):
         """Does a file exist at the given path?
 
         Like os.path.isfile
 
         Override this method in subclasses.
 
         Parameters
         ----------
         name : string
             The name of the file you are checking.
         path : string
             The relative path to the file's directory (with '/' as separator)
 
         Returns
         -------
         exists : bool
             Whether the file exists.
         """
         raise NotImplementedError('must be implemented in a subclass')
 
     def exists(self, path):
         """Does a file or directory exist at the given path?
 
         Like os.path.exists
 
         Parameters
         ----------
         path : string
             The relative path to the file's directory (with '/' as separator)
 
         Returns
         -------
         exists : bool
             Whether the target exists.
         """
         return self.file_exists(path) or self.dir_exists(path)
 
     def get(self, path, content=True, type=None, format=None):
         """Get the model of a file or directory with or without content."""
         raise NotImplementedError('must be implemented in a subclass')
 
     def save(self, model, path):
         """Save the file or directory and return the model with no content.
 
         Save implementations should call self.run_pre_save_hook(model=model, path=path)
         prior to writing any data.
         """
         raise NotImplementedError('must be implemented in a subclass')
 
     def delete_file(self, path):
         """Delete file or directory by path."""
         raise NotImplementedError('must be implemented in a subclass')
 
     def rename_file(self, old_path, new_path):
         """Rename a file."""
         raise NotImplementedError('must be implemented in a subclass')
 
     # ContentsManager API part 2: methods that have useable default
     # implementations, but can be overridden in subclasses.
 
     def delete(self, path):
         """Delete a file/directory and any associated checkpoints."""
+        path = path.strip('/')
+        if not path:
+            raise HTTPError(400, "Can't delete root")
         self.delete_file(path)
         self.checkpoints.delete_all_checkpoints(path)
 
     def rename(self, old_path, new_path):
         """Rename a file and any checkpoints associated with that file."""
         self.rename_file(old_path, new_path)
         self.checkpoints.rename_all_checkpoints(old_path, new_path)
 
     def update(self, model, path):
         """Update the file's path
 
         For use in PATCH requests, to enable renaming a file without
         re-uploading its contents. Only used for renaming at the moment.
         """
         path = path.strip('/')
         new_path = model.get('path', path).strip('/')
         if path != new_path:
             self.rename(path, new_path)
         model = self.get(new_path, content=False)
         return model
 
     def info_string(self):
         return "Serving contents"
 
     def get_kernel_path(self, path, model=None):
         """Return the API path for the kernel
         
         KernelManagers can turn this value into a filesystem path,
         or ignore it altogether.
 
         The default value here will start kernels in the directory of the
         notebook server. FileContentsManager overrides this to use the
         directory containing the notebook.
         """
         return ''
 
     def increment_filename(self, filename, path='', insert=''):
         """Increment a filename until it is unique.
 
         Parameters
         ----------
         filename : unicode
             The name of a file, including extension
         path : unicode
             The API path of the target's directory
 
         Returns
         -------
         name : unicode
             A filename that is unique, based on the input filename.
         """
         path = path.strip('/')
         basename, ext = os.path.splitext(filename)
         for i in itertools.count():
             if i:
                 insert_i = '{}{}'.format(insert, i)
             else:
                 insert_i = ''
             name = u'{basename}{insert}{ext}'.format(basename=basename,
                 insert=insert_i, ext=ext)
             if not self.exists(u'{}/{}'.format(path, name)):
                 break
         return name
 
     def validate_notebook_model(self, model):
         """Add failed-validation message to model"""
         try:
             validate(model['content'])
         except ValidationError as e:
             model['message'] = u'Notebook Validation failed: {}:\n{}'.format(
                 e.message, json.dumps(e.instance, indent=1, default=lambda obj: '<UNKNOWN>'),
             )
         return model
     
     def new_untitled(self, path='', type='', ext=''):
         """Create a new untitled file or directory in path
         
         path must be a directory
         
         File extension can be specified.
         
         Use `new` to create files with a fully specified path (including filename).
         """
         path = path.strip('/')
         if not self.dir_exists(path):
             raise HTTPError(404, 'No such directory: %s' % path)
         
         model = {}
         if type:
             model['type'] = type
         
         if ext == '.ipynb':
             model.setdefault('type', 'notebook')
         else:
             model.setdefault('type', 'file')
         
         insert = ''
         if model['type'] == 'directory':
             untitled = self.untitled_directory
             insert = ' '
         elif model['type'] == 'notebook':
             untitled = self.untitled_notebook
             ext = '.ipynb'
         elif model['type'] == 'file':
             untitled = self.untitled_file
         else:
             raise HTTPError(400, "Unexpected model type: %r" % model['type'])
         
         name = self.increment_filename(untitled + ext, path, insert=insert)
         path = u'{0}/{1}'.format(path, name)
         return self.new(model, path)
     
     def new(self, model=None, path=''):
         """Create a new file or directory and return its model with no content.
         
         To create a new untitled entity in a directory, use `new_untitled`.
         """
         path = path.strip('/')
         if model is None:
             model = {}
         
         if path.endswith('.ipynb'):
             model.setdefault('type', 'notebook')
         else:
             model.setdefault('type', 'file')
         
         # no content, not a directory, so fill out new-file model
         if 'content' not in model and model['type'] != 'directory':
             if model['type'] == 'notebook':
                 model['content'] = new_notebook()
                 model['format'] = 'json'
             else:
                 model['content'] = ''
                 model['type'] = 'file'
                 model['format'] = 'text'
         
         model = self.save(model, path)
         return model
 
     def copy(self, from_path, to_path=None):
         """Copy an existing file and return its new model.
 
         If to_path not specified, it will be the parent directory of from_path.
         If to_path is a directory, filename will increment `from_path-Copy#.ext`.
 
         from_path must be a full path to a file.
         """
         path = from_path.strip('/')
         if to_path is not None:
             to_path = to_path.strip('/')
 
         if '/' in path:
             from_dir, from_name = path.rsplit('/', 1)
         else:
             from_dir = ''
             from_name = path
         
         model = self.get(path)
         model.pop('path', None)
         model.pop('name', None)
         if model['type'] == 'directory':
             raise HTTPError(400, "Can't copy directories")
         
         if to_path is None:
             to_path = from_dir
         if self.dir_exists(to_path):
             name = copy_pat.sub(u'.', from_name)
             to_name = self.increment_filename(name, to_path, insert='-Copy')
             to_path = u'{0}/{1}'.format(to_path, to_name)
         
         model = self.save(model, to_path)
         return model
 
     def log_info(self):
         self.log.info(self.info_string())
 
     def trust_notebook(self, path):
         """Explicitly trust a notebook
 
         Parameters
         ----------
         path : string
             The path of a notebook
         """
         model = self.get(path)
         nb = model['content']
         self.log.warn("Trusting notebook %s", path)
         self.notary.mark_cells(nb, True)
         self.save(model, path)
 
     def check_and_sign(self, nb, path=''):
         """Check for trusted cells, and sign the notebook.
 
         Called as a part of saving notebooks.
 
         Parameters
         ----------
         nb : dict
             The notebook dict
         path : string
             The notebook's path (for logging)
         """
         if self.notary.check_cells(nb):
             self.notary.sign(nb)
         else:
             self.log.warn("Saving untrusted notebook %s", path)
 
     def mark_trusted_cells(self, nb, path=''):
         """Mark cells as trusted if the notebook signature matches.
 
         Called as a part of loading notebooks.
 
         Parameters
         ----------
         nb : dict
             The notebook object (in current nbformat)
         path : string
             The notebook's path (for logging)
         """
         trusted = self.notary.check_signature(nb)
         if not trusted:
             self.log.warn("Notebook %s is not trusted", path)
         self.notary.mark_cells(nb, trusted)
 
     def should_list(self, name):
         """Should this file/directory name be displayed in a listing?"""
         return not any(fnmatch(name, glob) for glob in self.hide_globs)
 
     # Part 3: Checkpoints API
     def create_checkpoint(self, path):
         """Create a checkpoint."""
         return self.checkpoints.create_checkpoint(self, path)
 
     def restore_checkpoint(self, checkpoint_id, path):
         """
         Restore a checkpoint.
         """
         self.checkpoints.restore_checkpoint(self, checkpoint_id, path)
 
     def list_checkpoints(self, path):
         return self.checkpoints.list_checkpoints(path)
 
     def delete_checkpoint(self, checkpoint_id, path):
         return self.checkpoints.delete_checkpoint(checkpoint_id, path)

IPython/html/services/contents/tests/test_manager.py

@@ -1,497 +1,503 b''
 # coding: utf-8
 """Tests for the notebook manager."""
 from __future__ import print_function
 
 import os
 import sys
 import time
 from contextlib import contextmanager
 
 from nose import SkipTest
 from tornado.web import HTTPError
 from unittest import TestCase
 from tempfile import NamedTemporaryFile
 
 from IPython.nbformat import v4 as nbformat
 
 from IPython.utils.tempdir import TemporaryDirectory
 from IPython.utils.traitlets import TraitError
 from IPython.testing import decorators as dec
 
 from ..filemanager import FileContentsManager
 
 
 def _make_dir(contents_manager, api_path):
     """
     Make a directory.
     """
     os_path = contents_manager._get_os_path(api_path)
     try:
         os.makedirs(os_path)
     except OSError:
         print("Directory already exists: %r" % os_path)
 
 
 class TestFileContentsManager(TestCase):
 
     @contextmanager
     def assertRaisesHTTPError(self, status, msg=None):
         msg = msg or "Should have raised HTTPError(%i)" % status
         try:
             yield
         except HTTPError as e:
             self.assertEqual(e.status_code, status)
         else:
             self.fail(msg)
 
     def symlink(self, contents_manager, src, dst):
         """Make a symlink to src from dst
         
         src and dst are api_paths
         """
         src_os_path = contents_manager._get_os_path(src)
         dst_os_path = contents_manager._get_os_path(dst)
         print(src_os_path, dst_os_path, os.path.isfile(src_os_path))
         os.symlink(src_os_path, dst_os_path)
 
     def test_root_dir(self):
         with TemporaryDirectory() as td:
             fm = FileContentsManager(root_dir=td)
             self.assertEqual(fm.root_dir, td)
 
     def test_missing_root_dir(self):
         with TemporaryDirectory() as td:
             root = os.path.join(td, 'notebook', 'dir', 'is', 'missing')
             self.assertRaises(TraitError, FileContentsManager, root_dir=root)
 
     def test_invalid_root_dir(self):
         with NamedTemporaryFile() as tf:
             self.assertRaises(TraitError, FileContentsManager, root_dir=tf.name)
 
     def test_get_os_path(self):
         # full filesystem path should be returned with correct operating system
         # separators.
         with TemporaryDirectory() as td:
             root = td
             fm = FileContentsManager(root_dir=root)
             path = fm._get_os_path('/path/to/notebook/test.ipynb')
             rel_path_list =  '/path/to/notebook/test.ipynb'.split('/')
             fs_path = os.path.join(fm.root_dir, *rel_path_list)
             self.assertEqual(path, fs_path)
 
             fm = FileContentsManager(root_dir=root)
             path = fm._get_os_path('test.ipynb')
             fs_path = os.path.join(fm.root_dir, 'test.ipynb')
             self.assertEqual(path, fs_path)
 
             fm = FileContentsManager(root_dir=root)
             path = fm._get_os_path('////test.ipynb')
             fs_path = os.path.join(fm.root_dir, 'test.ipynb')
             self.assertEqual(path, fs_path)
 
     def test_checkpoint_subdir(self):
         subd = u'sub ∂ir'
         cp_name = 'test-cp.ipynb'
         with TemporaryDirectory() as td:
             root = td
             os.mkdir(os.path.join(td, subd))
             fm = FileContentsManager(root_dir=root)
             cpm = fm.checkpoints
             cp_dir = cpm.checkpoint_path(
                 'cp', 'test.ipynb'
             )
             cp_subdir = cpm.checkpoint_path(
                 'cp', '/%s/test.ipynb' % subd
             )
         self.assertNotEqual(cp_dir, cp_subdir)
         self.assertEqual(cp_dir, os.path.join(root, cpm.checkpoint_dir, cp_name))
         self.assertEqual(cp_subdir, os.path.join(root, subd, cpm.checkpoint_dir, cp_name))
     
     @dec.skip_win32
     def test_bad_symlink(self):
         with TemporaryDirectory() as td:
             cm = FileContentsManager(root_dir=td)
             path = 'test bad symlink'
             _make_dir(cm, path)
 
             file_model = cm.new_untitled(path=path, ext='.txt')
 
             # create a broken symlink
             self.symlink(cm, "target", '%s/%s' % (path, 'bad symlink'))
             model = cm.get(path)
             self.assertEqual(model['content'], [file_model])
     
     @dec.skip_win32
     def test_good_symlink(self):
         with TemporaryDirectory() as td:
             cm = FileContentsManager(root_dir=td)
             parent = 'test good symlink'
             name = 'good symlink'
             path = '{0}/{1}'.format(parent, name)
             _make_dir(cm, parent)
 
             file_model = cm.new(path=parent + '/zfoo.txt')
 
             # create a good symlink
             self.symlink(cm, file_model['path'], path)
             symlink_model = cm.get(path, content=False)
             dir_model = cm.get(parent)
             self.assertEqual(
                 sorted(dir_model['content'], key=lambda x: x['name']),
                 [symlink_model, file_model],
             )
     
     def test_403(self):
         if hasattr(os, 'getuid'):
             if os.getuid() == 0:
                 raise SkipTest("Can't test permissions as root")
         if sys.platform.startswith('win'):
             raise SkipTest("Can't test permissions on Windows")
         
         with TemporaryDirectory() as td:
             cm = FileContentsManager(root_dir=td)
             model = cm.new_untitled(type='file')
             os_path = cm._get_os_path(model['path'])
         
             os.chmod(os_path, 0o400)
             try:
                 with cm.open(os_path, 'w') as f:
                     f.write(u"don't care")
             except HTTPError as e:
                 self.assertEqual(e.status_code, 403)
             else:
                 self.fail("Should have raised HTTPError(403)")
 
     def test_escape_root(self):
         with TemporaryDirectory() as td:
             cm = FileContentsManager(root_dir=td)
             # make foo, bar next to root
             with open(os.path.join(cm.root_dir, '..', 'foo'), 'w') as f:
                 f.write('foo')
             with open(os.path.join(cm.root_dir, '..', 'bar'), 'w') as f:
                 f.write('bar')
 
             with self.assertRaisesHTTPError(404):
                 cm.get('..')
             with self.assertRaisesHTTPError(404):
                 cm.get('foo/../../../bar')
             with self.assertRaisesHTTPError(404):
                 cm.delete('../foo')
             with self.assertRaisesHTTPError(404):
                 cm.rename('../foo', '../bar')
             with self.assertRaisesHTTPError(404):
                 cm.save(model={
                     'type': 'file',
                     'content': u'',
                     'format': 'text',
                 }, path='../foo')
 
 
 class TestContentsManager(TestCase):
     
     def setUp(self):
         self._temp_dir = TemporaryDirectory()
         self.td = self._temp_dir.name
         self.contents_manager = FileContentsManager(
             root_dir=self.td,
         )
 
     def tearDown(self):
         self._temp_dir.cleanup()
     
     def make_dir(self, api_path):
         """make a subdirectory at api_path
         
         override in subclasses if contents are not on the filesystem.
         """
         _make_dir(self.contents_manager, api_path)
 
     def add_code_cell(self, nb):
         output = nbformat.new_output("display_data", {'application/javascript': "alert('hi');"})
         cell = nbformat.new_code_cell("print('hi')", outputs=[output])
         nb.cells.append(cell)
 
     def new_notebook(self):
         cm = self.contents_manager
         model = cm.new_untitled(type='notebook')
         name = model['name']
         path = model['path']
 
         full_model = cm.get(path)
         nb = full_model['content']
         nb['metadata']['counter'] = int(1e6 * time.time())
         self.add_code_cell(nb)
 
         cm.save(full_model, path)
         return nb, name, path
 
     def test_new_untitled(self):
         cm = self.contents_manager
         # Test in root directory
         model = cm.new_untitled(type='notebook')
         assert isinstance(model, dict)
         self.assertIn('name', model)
         self.assertIn('path', model)
         self.assertIn('type', model)
         self.assertEqual(model['type'], 'notebook')
         self.assertEqual(model['name'], 'Untitled.ipynb')
         self.assertEqual(model['path'], 'Untitled.ipynb')
 
         # Test in sub-directory
         model = cm.new_untitled(type='directory')
         assert isinstance(model, dict)
         self.assertIn('name', model)
         self.assertIn('path', model)
         self.assertIn('type', model)
         self.assertEqual(model['type'], 'directory')
         self.assertEqual(model['name'], 'Untitled Folder')
         self.assertEqual(model['path'], 'Untitled Folder')
         sub_dir = model['path']
         
         model = cm.new_untitled(path=sub_dir)
         assert isinstance(model, dict)
         self.assertIn('name', model)
         self.assertIn('path', model)
         self.assertIn('type', model)
         self.assertEqual(model['type'], 'file')
         self.assertEqual(model['name'], 'untitled')
         self.assertEqual(model['path'], '%s/untitled' % sub_dir)
 
     def test_get(self):
         cm = self.contents_manager
         # Create a notebook
         model = cm.new_untitled(type='notebook')
         name = model['name']
         path = model['path']
 
         # Check that we 'get' on the notebook we just created
         model2 = cm.get(path)
         assert isinstance(model2, dict)
         self.assertIn('name', model2)
         self.assertIn('path', model2)
         self.assertEqual(model['name'], name)
         self.assertEqual(model['path'], path)
 
         nb_as_file = cm.get(path, content=True, type='file')
         self.assertEqual(nb_as_file['path'], path)
         self.assertEqual(nb_as_file['type'], 'file')
         self.assertEqual(nb_as_file['format'], 'text')
         self.assertNotIsInstance(nb_as_file['content'], dict)
 
         nb_as_bin_file = cm.get(path, content=True, type='file', format='base64')
         self.assertEqual(nb_as_bin_file['format'], 'base64')
 
         # Test in sub-directory
         sub_dir = '/foo/'
         self.make_dir('foo')
         model = cm.new_untitled(path=sub_dir, ext='.ipynb')
         model2 = cm.get(sub_dir + name)
         assert isinstance(model2, dict)
         self.assertIn('name', model2)
         self.assertIn('path', model2)
         self.assertIn('content', model2)
         self.assertEqual(model2['name'], 'Untitled.ipynb')
         self.assertEqual(model2['path'], '{0}/{1}'.format(sub_dir.strip('/'), name))
 
         # Test with a regular file.
         file_model_path = cm.new_untitled(path=sub_dir, ext='.txt')['path']
         file_model = cm.get(file_model_path)
         self.assertDictContainsSubset(
             {
                 'content': u'',
                 'format': u'text',
                 'mimetype': u'text/plain',
                 'name': u'untitled.txt',
                 'path': u'foo/untitled.txt',
                 'type': u'file',
                 'writable': True,
             },
             file_model,
         )
         self.assertIn('created', file_model)
         self.assertIn('last_modified', file_model)
 
         # Test getting directory model
 
         # Create a sub-sub directory to test getting directory contents with a
         # subdir.
         self.make_dir('foo/bar')
         dirmodel = cm.get('foo')
         self.assertEqual(dirmodel['type'], 'directory')
         self.assertIsInstance(dirmodel['content'], list)
         self.assertEqual(len(dirmodel['content']), 3)
         self.assertEqual(dirmodel['path'], 'foo')
         self.assertEqual(dirmodel['name'], 'foo')
 
         # Directory contents should match the contents of each individual entry
         # when requested with content=False.
         model2_no_content = cm.get(sub_dir + name, content=False)
         file_model_no_content = cm.get(u'foo/untitled.txt', content=False)
         sub_sub_dir_no_content = cm.get('foo/bar', content=False)
         self.assertEqual(sub_sub_dir_no_content['path'], 'foo/bar')
         self.assertEqual(sub_sub_dir_no_content['name'], 'bar')
 
         for entry in dirmodel['content']:
             # Order isn't guaranteed by the spec, so this is a hacky way of
             # verifying that all entries are matched.
             if entry['path'] == sub_sub_dir_no_content['path']:
                 self.assertEqual(entry, sub_sub_dir_no_content)
             elif entry['path'] == model2_no_content['path']:
                 self.assertEqual(entry, model2_no_content)
             elif entry['path'] == file_model_no_content['path']:
                 self.assertEqual(entry, file_model_no_content)
             else:
                 self.fail("Unexpected directory entry: %s" % entry())
 
         with self.assertRaises(HTTPError):
             cm.get('foo', type='file')
 
     def test_update(self):
         cm = self.contents_manager
         # Create a notebook
         model = cm.new_untitled(type='notebook')
         name = model['name']
         path = model['path']
 
         # Change the name in the model for rename
         model['path'] = 'test.ipynb'
         model = cm.update(model, path)
         assert isinstance(model, dict)
         self.assertIn('name', model)
         self.assertIn('path', model)
         self.assertEqual(model['name'], 'test.ipynb')
 
         # Make sure the old name is gone
         self.assertRaises(HTTPError, cm.get, path)
 
         # Test in sub-directory
         # Create a directory and notebook in that directory
         sub_dir = '/foo/'
         self.make_dir('foo')
         model = cm.new_untitled(path=sub_dir, type='notebook')
         path = model['path']
 
         # Change the name in the model for rename
         d = path.rsplit('/', 1)[0]
         new_path = model['path'] = d + '/test_in_sub.ipynb'
         model = cm.update(model, path)
         assert isinstance(model, dict)
         self.assertIn('name', model)
         self.assertIn('path', model)
         self.assertEqual(model['name'], 'test_in_sub.ipynb')
         self.assertEqual(model['path'], new_path)
 
         # Make sure the old name is gone
         self.assertRaises(HTTPError, cm.get, path)
 
     def test_save(self):
         cm = self.contents_manager
         # Create a notebook
         model = cm.new_untitled(type='notebook')
         name = model['name']
         path = model['path']
 
         # Get the model with 'content'
         full_model = cm.get(path)
 
         # Save the notebook
         model = cm.save(full_model, path)
         assert isinstance(model, dict)
         self.assertIn('name', model)
         self.assertIn('path', model)
         self.assertEqual(model['name'], name)
         self.assertEqual(model['path'], path)
 
         # Test in sub-directory
         # Create a directory and notebook in that directory
         sub_dir = '/foo/'
         self.make_dir('foo')
         model = cm.new_untitled(path=sub_dir, type='notebook')
         name = model['name']
         path = model['path']
         model = cm.get(path)
 
         # Change the name in the model for rename
         model = cm.save(model, path)
         assert isinstance(model, dict)
         self.assertIn('name', model)
         self.assertIn('path', model)
         self.assertEqual(model['name'], 'Untitled.ipynb')
         self.assertEqual(model['path'], 'foo/Untitled.ipynb')
 
     def test_delete(self):
         cm = self.contents_manager
         # Create a notebook
         nb, name, path = self.new_notebook()
 
         # Delete the notebook
         cm.delete(path)
 
         # Check that deleting a non-existent path raises an error.
         self.assertRaises(HTTPError, cm.delete, path)
 
         # Check that a 'get' on the deleted notebook raises and error
         self.assertRaises(HTTPError, cm.get, path)
 
+    def test_delete_root(self):
+        cm = self.contents_manager
+        with self.assertRaises(HTTPError) as err:
+            cm.delete('')
+        self.assertEqual(err.exception.status_code, 400)
+
     def test_copy(self):
         cm = self.contents_manager
         parent = u'å b'
         name = u'nb √.ipynb'
         path = u'{0}/{1}'.format(parent, name)
         self.make_dir(parent)
 
         orig = cm.new(path=path)
         # copy with unspecified name
         copy = cm.copy(path)
         self.assertEqual(copy['name'], orig['name'].replace('.ipynb', '-Copy1.ipynb'))
 
         # copy with specified name
         copy2 = cm.copy(path, u'å b/copy 2.ipynb')
         self.assertEqual(copy2['name'], u'copy 2.ipynb')
         self.assertEqual(copy2['path'], u'å b/copy 2.ipynb')
         # copy with specified path
         copy2 = cm.copy(path, u'/')
         self.assertEqual(copy2['name'], name)
         self.assertEqual(copy2['path'], name)
 
     def test_trust_notebook(self):
         cm = self.contents_manager
         nb, name, path = self.new_notebook()
 
         untrusted = cm.get(path)['content']
         assert not cm.notary.check_cells(untrusted)
 
         # print(untrusted)
         cm.trust_notebook(path)
         trusted = cm.get(path)['content']
         # print(trusted)
         assert cm.notary.check_cells(trusted)
 
     def test_mark_trusted_cells(self):
         cm = self.contents_manager
         nb, name, path = self.new_notebook()
 
         cm.mark_trusted_cells(nb, path)
         for cell in nb.cells:
             if cell.cell_type == 'code':
                 assert not cell.metadata.trusted
 
         cm.trust_notebook(path)
         nb = cm.get(path)['content']
         for cell in nb.cells:
             if cell.cell_type == 'code':
                 assert cell.metadata.trusted
 
     def test_check_and_sign(self):
         cm = self.contents_manager
         nb, name, path = self.new_notebook()
 
         cm.mark_trusted_cells(nb, path)
         cm.check_and_sign(nb, path)
         assert not cm.notary.check_signature(nb)
 
         cm.trust_notebook(path)
         nb = cm.get(path)['content']
         cm.mark_trusted_cells(nb, path)
         cm.check_and_sign(nb, path)
         assert cm.notary.check_signature(nb)