Merge lp:~frankban/charms/precise/juju-gui/guiserver-views into lp:~juju-gui/charms/precise/juju-gui/trunk

[Francesco Banconi]

Bundle deployment views.

This branch includes the implementation of the
bundle views. Their goal is to handle the bundle
deployment request/response process.

Views interact with the Deployer instance
(not yet implemented) in order to schedule,
run and observe bundle deployments.

https://codereview.appspot.com/12927049/

[Francesco Banconi (frankban)]

Reviewers: mp+181020_code.launchpad.net,

Message:
Please take a look.

Description:
Bundle deployment views.

This branch includes the implementation of the
bundle views. Their goal is to handle the bundle
deployment request/response process.

Views interact with the Deployer instance
(not yet implemented) in order to schedule,
run and observe bundle deployments.

https://code.launchpad.net/~frankban/charms/precise/juju-gui/guiserver-views/+merge/181020

(do not edit description out of merge proposal)

Please review this at https://codereview.appspot.com/12927049/

Affected files:
   A [revision details]
   M revision
   M server/guiserver/bundles/__init__.py
   A server/guiserver/bundles/utils.py
   A server/guiserver/bundles/views.py
   A server/guiserver/tests/bundles/test_utils.py
   A server/guiserver/tests/bundles/test_views.py
   M server/guiserver/tests/helpers.py

[Brad Crittenden (bac)]

LGTM. Nice tests and well-organized helpers / factoring.

https://codereview.appspot.com/12927049/diff/1/server/guiserver/bundles/utils.py
File server/guiserver/bundles/utils.py (right):

https://codereview.appspot.com/12927049/diff/1/server/guiserver/bundles/utils.py#newcode36
server/guiserver/bundles/utils.py:36: raise response(error='unauthorized
access: unknown user')
The error message is a little misleading. "unknown user" implies we
have a user but don't recognize her when in fact there is no logged in
user.

How about:

error='unauthorized access: no user logged in.' ?

https://codereview.appspot.com/12927049/diff/1/server/guiserver/bundles/views.py
File server/guiserver/bundles/views.py (right):

https://codereview.appspot.com/12927049/diff/1/server/guiserver/bundles/views.py#newcode37
server/guiserver/bundles/views.py:37: creating this kind of responses:
s/creating this kind of responses/create these responses

https://codereview.appspot.com/12927049/diff/1/server/guiserver/bundles/views.py#newcode173
server/guiserver/bundles/views.py:173: raise response(error='invalid
request: invalid data parameters')
Perhaps list the params in the error message?

https://codereview.appspot.com/12927049/

[lp:~frankban/charms/precise/juju-gui/guiserver-views]

109. By Francesco Banconi on 2013-08-20

Changes as per review.

[Francesco Banconi (frankban)]

*** Submitted:

Bundle deployment views.

This branch includes the implementation of the
bundle views. Their goal is to handle the bundle
deployment request/response process.

Views interact with the Deployer instance
(not yet implemented) in order to schedule,
run and observe bundle deployments.

R=bac, benji
CC=
https://codereview.appspot.com/12927049

https://codereview.appspot.com/12927049/diff/1/server/guiserver/bundles/utils.py
File server/guiserver/bundles/utils.py (right):

https://codereview.appspot.com/12927049/diff/1/server/guiserver/bundles/utils.py#newcode36
server/guiserver/bundles/utils.py:36: raise response(error='unauthorized
access: unknown user')
On 2013/08/20 13:24:09, bac wrote:
> The error message is a little misleading. "unknown user" implies we
have a user
> but don't recognize her when in fact there is no logged in user.

> How about:

> error='unauthorized access: no user logged in.' ?

You are right, changed the message.

https://codereview.appspot.com/12927049/diff/1/server/guiserver/bundles/views.py
File server/guiserver/bundles/views.py (right):

https://codereview.appspot.com/12927049/diff/1/server/guiserver/bundles/views.py#newcode37
server/guiserver/bundles/views.py:37: creating this kind of responses:
On 2013/08/20 13:24:09, bac wrote:
> s/creating this kind of responses/create these responses

Done.

https://codereview.appspot.com/12927049/diff/1/server/guiserver/bundles/views.py#newcode60
server/guiserver/bundles/views.py:60: (the latter will be eventually
fixed switching to a newer version of Python).
On 2013/08/20 13:28:10, benji wrote:
> I was wondering about why we didn't use Python 3 for this server. Is
there a
> Tornado requirement for Python 2?

No, Tornado is fully compatible with Python3. And I guess it should be
quite easy to port the GUI server to Python3. The problem here is that
juju-deployer only supports Python2, and therefore, for now, we cannot
upgrade.

https://codereview.appspot.com/12927049/diff/1/server/guiserver/bundles/views.py#newcode148
server/guiserver/bundles/views.py:148: deployment being observed. If
unseen changes are available, a response is
On 2013/08/20 13:28:10, benji wrote:
> "unsent" might be slightly clearer than "unseen".

Done.

https://codereview.appspot.com/12927049/diff/1/server/guiserver/bundles/views.py#newcode149
server/guiserver/bundles/views.py:149: suddenly returned containing the
changes. Otherwise, this views suspends
On 2013/08/20 13:28:10, benji wrote:
> I think "immediately" would be a bit better than "suddenly".

Done.

https://codereview.appspot.com/12927049/diff/1/server/guiserver/bundles/views.py#newcode173
server/guiserver/bundles/views.py:173: raise response(error='invalid
request: invalid data parameters')
On 2013/08/20 13:24:09, bac wrote:
> Perhaps list the params in the error message?

Done.

https://codereview.appspot.com/12927049/

[Francesco Banconi (frankban)]

Thank you both for the reviews.

https://codereview.appspot.com/12927049/

=== modified file 'revision'
--- revision	2013-08-19 08:50:17 +0000
+++ revision	2013-08-20 14:10:33 +0000
@@ -1,1 +1,1 @@
-71
+72

=== modified file 'server/guiserver/bundles/__init__.py'
--- server/guiserver/bundles/__init__.py	2013-08-19 08:41:44 +0000
+++ server/guiserver/bundles/__init__.py	2013-08-20 14:10:33 +0000
@@ -27,7 +27,8 @@
         - validate(user, name, bundle) -> Future (str or None);
         - import_bundle(user, name, bundle) -> int (a deployment id);
         - watch(deployment_id) -> int or None (a watcher id);
-        - next(watcher_id) -> Future (changes or None).
+        - next(watcher_id) -> Future (changes or None);
+        - status() -> list (of changes).
 
       The following arguments are passed to the validate and import_bundle
       interface methods:

=== added file 'server/guiserver/bundles/utils.py'
--- server/guiserver/bundles/utils.py	1970-01-01 00:00:00 +0000
+++ server/guiserver/bundles/utils.py	2013-08-20 14:10:33 +0000
@@ -0,0 +1,54 @@
+# This file is part of the Juju GUI, which lets users view and manage Juju
+# environments within a graphical interface (https://launchpad.net/juju-gui).
+# Copyright (C) 2013 Canonical Ltd.
+#
+# This program is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License version 3, as published by
+# the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranties of MERCHANTABILITY,
+# SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Bundle deployment utility functions."""
+
+from functools import wraps
+import logging
+
+from tornado import gen
+
+
+def require_authenticated_user(view):
+    """Require the user to be authenticated when executing the decorated view.
+
+    This function can be used to decorate bundle views. Each view receives
+    a request and a deployer, and the user instance is stored in request.user.
+    If the user is not authenticated an error response is raised when calling
+    the view. Otherwise, the view is executed normally.
+    """
+    @wraps(view)
+    def decorated(request, deployer):
+        if not request.user.is_authenticated:
+            raise response(error='unauthorized access: no user logged in')
+        return view(request, deployer)
+    return decorated
+
+
+def response(info=None, error=None):
+    """Create a response containing the given (optional) info and error values.
+
+    This function is intended to be used by bundles views.
+    Return a gen.Return instance, so that the result of this method can easily
+    be raised from coroutines.
+    """
+    if info is None:
+        info = {}
+    data = {'Response': info}
+    if error is not None:
+        logging.error('deployer: {}'.format(error))
+        data['Error'] = error
+    return gen.Return(data)

=== added file 'server/guiserver/bundles/views.py'
--- server/guiserver/bundles/views.py	1970-01-01 00:00:00 +0000
+++ server/guiserver/bundles/views.py	2013-08-20 14:10:33 +0000
@@ -0,0 +1,177 @@
+# This file is part of the Juju GUI, which lets users view and manage Juju
+# environments within a graphical interface (https://launchpad.net/juju-gui).
+# Copyright (C) 2013 Canonical Ltd.
+#
+# This program is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License version 3, as published by
+# the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranties of MERCHANTABILITY,
+# SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Bundle deployment views.
+
+This module includes the views used to create responses for bundle deployments
+related requests. The bundles protocol, described in the bundles package
+docstring, mimics the request/response paradigm over a WebSocket. Views are
+simple functions that, given a request, return a response to be sent back to
+the API client. Each view receives the following arguments:
+
+    - request: a request object with two attributes:
+      - request.params: a dict representing the parameters sent by the client;
+      - request.user: the current user (an instance of guiserver.auth.User);
+    - deployer: a Deployer instance, ready to be used to schedule/start/observe
+      bundle deployments.
+
+The response returned by views must be a Future containing the response data as
+a dict-like object, e.g.:
+
+    {'Response': {}, 'Error': 'this field is optional'}
+
+The response function defined in the guiserver.bundles.utils module helps
+create these responses:
+
+    from guiserver.bundles.utils import response
+
+    @gen.coroutine
+    def succeeding_view(request, deployer)
+        raise response('Success!')
+
+    @gen.coroutine
+    def failing_view(request, deployer)
+        raise response(error='Boo!')
+
+Use the require_authenticated_user decorator if the view requires a logged in
+user, e.g.:
+
+    @gen.coroutine
+    @require_authenticated_user
+    def protected_view(request, deployer):
+        # This function body is executed only if the user is authenticated.
+
+As seen in the examples above, views are also coroutines: they must be
+decorated with tornado.gen.coroutine, they can suspend their own execution
+using "yield", and they must return their results using "raise response(...)"
+(the latter will be eventually fixed switching to a newer version of Python).
+"""
+
+from tornado import gen
+import yaml
+
+from guiserver.bundles.utils import (
+    require_authenticated_user,
+    response,
+)
+
+
+def _validate_import_params(params):
+    """Parse the request data and return a (name, bundle) tuple.
+
+    In the tuple:
+      - name is the name of the bundle to be imported;
+      - bundle is the YAML decoded bundle object.
+
+    Raise a ValueError if data represents an invalid request.
+    """
+    name = params.get('Name')
+    contents = params.get('YAML')
+    if not (name and contents):
+        raise ValueError('invalid data parameters')
+    try:
+        bundles = yaml.load(contents, Loader=yaml.SafeLoader)
+    except Exception as err:
+        raise ValueError('invalid YAML contents: {}'.format(err))
+    bundle = bundles.get(name)
+    if bundle is None:
+        raise ValueError('bundle {} not found'.format(name))
+    return name, bundle
+
+
[e-mail]
+@require_authenticated_user
+def import_bundle(request, deployer):
+    """Start or schedule a bundle deployment.
+
+    If the request is valid, the response will contain the DeploymentId
+    assigned to the bundle deployment.
+
+    Request: 'Import'.
+    Parameters example: {'Name': 'bundle-name', 'YAML': 'bundles'}.
+    """
+    # Validate the request parameters.
+    try:
+        name, bundle = _validate_import_params(request.params)
+    except ValueError as err:
+        raise response(error='invalid request: {}'.format(err))
+    # Validate the bundle against the current state of the Juju environment.
+    err = yield deployer.validate(request.user, name, bundle)
+    if err is not None:
+        raise response(error='invalid request: {}'.format(err))
+    # Add the bundle deployment to the Deployer queue.
+    deployment_id = deployer.import_bundle(request.user, name, bundle)
+    raise response({'DeploymentId': deployment_id})
+
+
[e-mail]
+@require_authenticated_user
+def watch(request, deployer):
+    """Handle requests for watching a given deployment.
+
+    The deployment is identified in the request by the DeploymentId parameter.
+    If the request is valid, the response will contain the WatcherId
+    to be used to observe the deployment progress.
+
+    Request: 'Watch'.
+    Parameters example: {'DeploymentId': 42}.
+    """
+    deployment_id = request.params.get('DeploymentId')
+    if deployment_id is None:
+        raise response(error='invalid request: invalid data parameters')
+    # Retrieve a watcher identifier from the Deployer.
+    watcher_id = deployer.watch(deployment_id)
+    if watcher_id is None:
+        raise response(error='invalid request: deployment not found')
+    raise response({'WatcherId': watcher_id})
+
+
[e-mail]
+@require_authenticated_user
+def next(request, deployer):
+    """Wait until a new deployment event is available to be sent to the client.
+
+    The request params must include a WatcherId value, used to identify the
+    deployment being observed. If unsent changes are available, a response is
+    immediately returned containing the changes. Otherwise, this views suspends
+    its execution until a new change is notified by the Deployer.
+
+    Request: 'Next'.
+    Parameters example: {'WatcherId': 47}.
+    """
+    watcher_id = request.params.get('WatcherId')
+    if watcher_id is None:
+        raise response(error='invalid request: invalid data parameters')
+    # Wait for the Deployer to send changes.
+    changes = yield deployer.next(watcher_id)
+    if changes is None:
+        raise response(error='invalid request: invalid watcher identifier')
+    raise response({'Changes': changes})
+
+
[e-mail]
+@require_authenticated_user
+def status(request, deployer):
+    """Return the current status of all the bundle deployments.
+
+    The 'Status' request does not receive parameters.
+    """
+    if request.params:
+        params = ', '.join(request.params)
+        error = 'invalid request: invalid data parameters: {}'.format(params)
+        raise response(error=error)
+    last_changes = deployer.status()
+    raise response({'LastChanges': last_changes})

=== added file 'server/guiserver/tests/bundles/test_utils.py'
--- server/guiserver/tests/bundles/test_utils.py	1970-01-01 00:00:00 +0000
+++ server/guiserver/tests/bundles/test_utils.py	2013-08-20 14:10:33 +0000
@@ -0,0 +1,108 @@
+# This file is part of the Juju GUI, which lets users view and manage Juju
+# environments within a graphical interface (https://launchpad.net/juju-gui).
+# Copyright (C) 2013 Canonical Ltd.
+#
+# This program is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License version 3, as published by
+# the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranties of MERCHANTABILITY,
+# SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Tests for the deployment utility functions."""
+
+import unittest
+
+from tornado import gen
+from tornado.testing import(
+    AsyncTestCase,
+    ExpectLog,
+    gen_test,
+    LogTrapTestCase,
+)
+
+from guiserver.bundles import utils
+from guiserver.tests import helpers
+
+
+class TestRequireAuthenticatedUser(
+        helpers.BundlesTestMixin, LogTrapTestCase, AsyncTestCase):
+
+    deployer = 'fake-deployer'
+
+    def make_view(self):
+        """Return a view to be used for tests.
+
+        The resulting callable must be called with a request object as first
+        argument and with self.deployer as second argument.
+        """
+        @gen.coroutine
+        @utils.require_authenticated_user
+        def myview(request, deployer):
+            """An example testing view."""
+            self.assertEqual(self.deployer, deployer)
+            raise utils.response(info='ok')
+        return myview
+
+    @gen_test
+    def test_authenticated(self):
+        # The view is executed normally if the user is authenticated.
+        view = self.make_view()
+        request = self.make_view_request(is_authenticated=True)
+        response = yield view(request, self.deployer)
+        self.assertEqual({'Response': 'ok'}, response)
+
+    @gen_test
+    def test_not_authenticated(self):
+        # The view returns an error response if the user is not authenticated.
+        view = self.make_view()
+        request = self.make_view_request(is_authenticated=False)
+        response = yield view(request, self.deployer)
+        expected = {
+            'Response': {},
+            'Error': 'unauthorized access: no user logged in',
+        }
+        self.assertEqual(expected, response)
+
+    def test_wrap(self):
+        # The decorated view looks like the wrapped function.
+        view = self.make_view()
+        self.assertEqual('myview', view.__name__)
+        self.assertEqual('An example testing view.', view.__doc__)
+
+
+class TestResponse(LogTrapTestCase, unittest.TestCase):
+
+    def assert_response(self, expected, response):
+        """Ensure the given gen.Return instance contains the expected response.
+        """
+        self.assertIsInstance(response, gen.Return)
+        self.assertEqual(expected, response.value)
+
+    def test_empty(self):
+        # An empty response is correctly generated.
+        expected = {'Response': {}}
+        response = utils.response()
+        self.assert_response(expected, response)
+
+    def test_success(self):
+        # A success response is correctly generated.
+        expected = {'Response': {'foo': 'bar'}}
+        response = utils.response({'foo': 'bar'})
+        self.assert_response(expected, response)
+
+    def test_failure(self):
+        # A failure response is correctly generated.
+        expected = {'Error': 'an error occurred', 'Response': {}}
+        response = utils.response(error='an error occurred')
+        self.assert_response(expected, response)
+
+    def test_log_failure(self):
+        # An error log is written when a failure response is generated.
+        with ExpectLog('', 'deployer: an error occurred', required=True):
+            utils.response(error='an error occurred')

=== added file 'server/guiserver/tests/bundles/test_views.py'
--- server/guiserver/tests/bundles/test_views.py	1970-01-01 00:00:00 +0000
+++ server/guiserver/tests/bundles/test_views.py	2013-08-20 14:10:33 +0000
@@ -0,0 +1,259 @@
+# This file is part of the Juju GUI, which lets users view and manage Juju
+# environments within a graphical interface (https://launchpad.net/juju-gui).
+# Copyright (C) 2013 Canonical Ltd.
+#
+# This program is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License version 3, as published by
+# the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranties of MERCHANTABILITY,
+# SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Tests for the bundle deployment views."""
+
+import mock
+from tornado import concurrent
+from tornado.testing import(
+    AsyncTestCase,
+    ExpectLog,
+    gen_test,
+    LogTrapTestCase,
+)
+
+from guiserver.bundles import views
+from guiserver.tests import helpers
+
+
+class ViewsTestMixin(object):
+    """Base helpers and common tests for all the view tests.
+
+    Subclasses must define a get_view() method returning the view function to
+    be tested. Subclasses can also override the invalid_params and
+    invalid_params_error attributes, used to test the view in the case the
+    passed parameters are not valid.
+    """
+
+    invalid_params = {'No-such': 'parameter'}
+    invalid_params_error = 'invalid request: invalid data parameters'
+
+    def setUp(self):
+        super(ViewsTestMixin, self).setUp()
+        self.view = self.get_view()
+        self.deployer = mock.Mock()
+
+    def make_future(self, result):
+        """Create and return a Future containing the given result."""
+        future = concurrent.Future()
+        future.set_result(result)
+        return future
+
+    @gen_test
+    def test_not_authenticated(self):
+        # An error response is returned if the user is not authenticated.
+        request = self.make_view_request(is_authenticated=False)
+        expected_log = 'deployer: unauthorized access: no user logged in'
+        with ExpectLog('', expected_log, required=True):
+            response = yield self.view(request, self.deployer)
+        expected_response = {
+            'Response': {},
+            'Error': 'unauthorized access: no user logged in',
+        }
+        self.assertEqual(expected_response, response)
+        # The Deployer methods have not been called.
+        self.assertEqual(0, len(self.deployer.mock_calls))
+
+    @gen_test
+    def test_invalid_parameters(self):
+        # An error response is returned if the parameters in the request are
+        # not valid.
+        request = self.make_view_request(params=self.invalid_params)
+        expected_log = 'deployer: {}'.format(self.invalid_params_error)
+        with ExpectLog('', expected_log, required=True):
+            response = yield self.view(request, self.deployer)
+        expected_response = {
+            'Response': {},
+            'Error': self.invalid_params_error,
+        }
+        self.assertEqual(expected_response, response)
+        # The Deployer methods have not been called.
+        self.assertEqual(0, len(self.deployer.mock_calls))
+
+
+class TestImportBundle(
+        ViewsTestMixin, helpers.BundlesTestMixin, LogTrapTestCase,
+        AsyncTestCase):
+
+    def get_view(self):
+        return views.import_bundle
+
+    @gen_test
+    def test_invalid_yaml(self):
+        # An error response is returned if an invalid YAML encoded string is
+        # passed.
+        params = {'Name': 'bundle-name', 'YAML': 42}
+        request = self.make_view_request(params=params)
+        response = yield self.view(request, self.deployer)
+        expected_response = {
+            'Response': {},
+            'Error': 'invalid request: invalid YAML contents: '
+                     "'int' object has no attribute 'read'",
+        }
+        self.assertEqual(expected_response, response)
+        # The Deployer methods have not been called.
+        self.assertEqual(0, len(self.deployer.mock_calls))
+
+    @gen_test
+    def test_bundle_not_found(self):
+        # An error response is returned if the requested bundle name is not
+        # found in the bundle YAML contents.
+        params = {'Name': 'no-such-bundle', 'YAML': 'mybundle: mycontents'}
+        request = self.make_view_request(params=params)
+        response = yield self.view(request, self.deployer)
+        expected_response = {
+            'Response': {},
+            'Error': 'invalid request: bundle no-such-bundle not found',
+        }
+        self.assertEqual(expected_response, response)
+        # The Deployer methods have not been called.
+        self.assertEqual(0, len(self.deployer.mock_calls))
+
+    @gen_test
+    def test_invalid_bundle(self):
+        # An error response is returned if the bundle cannot be imported in the
+        # current Juju environment.
+        params = {'Name': 'mybundle', 'YAML': 'mybundle: mycontents'}
+        request = self.make_view_request(params=params)
+        # Simulate an error returned by the Deployer validate method.
+        self.deployer.validate.return_value = self.make_future('an error')
+        # Execute the view.
+        response = yield self.view(request, self.deployer)
+        expected_response = {
+            'Response': {},
+            'Error': 'invalid request: an error',
+        }
+        self.assertEqual(expected_response, response)
+        # The Deployer validate method has been called.
+        self.deployer.validate.assert_called_once_with(
+            request.user, 'mybundle', 'mycontents')
+
+    @gen_test
+    def test_success(self):
+        # The response includes the deployment identifier.
+        params = {'Name': 'mybundle', 'YAML': 'mybundle: mycontents'}
+        request = self.make_view_request(params=params)
+        # Set up the Deployer mock.
+        self.deployer.validate.return_value = self.make_future(None)
+        self.deployer.import_bundle.return_value = 42
+        # Execute the view.
+        response = yield self.view(request, self.deployer)
+        expected_response = {'Response': {'DeploymentId': 42}}
+        self.assertEqual(expected_response, response)
+        # Ensure the Deployer methods have been correctly called.
+        args = (request.user, 'mybundle', 'mycontents')
+        self.deployer.validate.assert_called_once_with(*args)
+        self.deployer.import_bundle.assert_called_once_with(*args)
+
+
+class TestWatch(
+        ViewsTestMixin, helpers.BundlesTestMixin, LogTrapTestCase,
+        AsyncTestCase):
+
+    def get_view(self):
+        return views.watch
+
+    @gen_test
+    def test_deployment_not_found(self):
+        # An error response is returned if the deployment identifier is not
+        # valid.
+        request = self.make_view_request(params={'DeploymentId': 42})
+        # Set up the Deployer mock.
+        self.deployer.watch.return_value = None
+        # Execute the view.
+        response = yield self.view(request, self.deployer)
+        expected_response = {
+            'Response': {},
+            'Error': 'invalid request: deployment not found',
+        }
+        self.assertEqual(expected_response, response)
+        # Ensure the Deployer methods have been correctly called.
+        self.deployer.watch.assert_called_once_with(42)
+
+    @gen_test
+    def test_success(self):
+        # The response includes the watcher identifier.
+        request = self.make_view_request(params={'DeploymentId': 42})
+        # Set up the Deployer mock.
+        self.deployer.watch.return_value = 47
+        # Execute the view.
+        response = yield self.view(request, self.deployer)
+        expected_response = {'Response': {'WatcherId': 47}}
+        self.assertEqual(expected_response, response)
+        # Ensure the Deployer methods have been correctly called.
+        self.deployer.watch.assert_called_once_with(42)
+
+
+class TestNext(
+        ViewsTestMixin, helpers.BundlesTestMixin, LogTrapTestCase,
+        AsyncTestCase):
+
+    def get_view(self):
+        return views.next
+
+    @gen_test
+    def test_invalid_watcher_identifier(self):
+        # An error response is returned if the watcher identifier is not valid.
+        request = self.make_view_request(params={'WatcherId': 42})
+        # Set up the Deployer mock.
+        self.deployer.next.return_value = self.make_future(None)
+        # Execute the view.
+        response = yield self.view(request, self.deployer)
+        expected_response = {
+            'Response': {},
+            'Error': 'invalid request: invalid watcher identifier',
+        }
+        self.assertEqual(expected_response, response)
+        # Ensure the Deployer methods have been correctly called.
+        self.deployer.next.assert_called_once_with(42)
+
+    @gen_test
+    def test_success(self):
+        # The response includes the deployment changes.
+        request = self.make_view_request(params={'WatcherId': 42})
+        # Set up the Deployer mock.
+        changes = ['change1', 'change2']
+        self.deployer.next.return_value = self.make_future(changes)
+        # Execute the view.
+        response = yield self.view(request, self.deployer)
+        expected_response = {'Response': {'Changes': changes}}
+        self.assertEqual(expected_response, response)
+        # Ensure the Deployer methods have been correctly called.
+        self.deployer.next.assert_called_once_with(42)
+
+
+class TestStatus(
+        ViewsTestMixin, helpers.BundlesTestMixin, LogTrapTestCase,
+        AsyncTestCase):
+
+    invalid_params_error = 'invalid request: invalid data parameters: No-such'
+
+    def get_view(self):
+        return views.status
+
+    @gen_test
+    def test_success(self):
+        # The response includes the watcher identifier.
+        request = self.make_view_request()
+        # Set up the Deployer mock.
+        last_changes = ['change1', 'change2']
+        self.deployer.status.return_value = last_changes
+        # Execute the view.
+        response = yield self.view(request, self.deployer)
+        expected_response = {'Response': {'LastChanges': last_changes}}
+        self.assertEqual(expected_response, response)
+        # Ensure the Deployer methods have been correctly called.
+        self.deployer.status.assert_called_once_with()

=== modified file 'server/guiserver/tests/helpers.py'
--- server/guiserver/tests/helpers.py	2013-08-19 13:56:31 +0000
+++ server/guiserver/tests/helpers.py	2013-08-20 14:10:33 +0000
@@ -18,6 +18,7 @@
 
 import json
 
+import mock
 from tornado import websocket
 import yaml
 
@@ -179,6 +180,20 @@
         all_contents = yaml.load(self.bundle)
         return all_contents.items()[0]
 
+    def make_view_request(self, params=None, is_authenticated=True):
+        """Create and return a mock request to be passed to bundle views.
+
+        The resulting request contains the given parameters and a
+        guiserver.auth.User instance.
+        If is_authenticated is True, the user in the request is logged in.
+        """
+        if params is None:
+            params = {}
+        user = auth.User(
+            username='user', password='passwd',
+            is_authenticated=is_authenticated)
+        return mock.Mock(params=params, user=user)
+
 
 class WSSTestMixin(object):
     """Add some helper methods for testing secure WebSocket handlers."""