extracted a leap attachment store, handling all attachment responsibilities, including saving attachments.

Issue #548

10 files changed, 214 insertions, 99 deletions

diff --git a/service/pixelated/adapter/mailstore/leap_attachment_store.py b/service/pixelated/adapter/mailstore/leap_attachment_store.py
new file mode 100644
index 00000000..86121db9
--- /dev/null
+++ b/service/pixelated/adapter/mailstore/leap_attachment_store.py
@@ -0,0 +1,61 @@
+
+import quopri
+import base64
+from email import encoders
+from leap.mail.adaptors.soledad import SoledadMailAdaptor, ContentDocWrapper
+from twisted.internet import defer
+from email.mime.nonmultipart import MIMENonMultipart
+from email.mime.multipart import MIMEMultipart
+from leap.mail.mail import Message
+
+
+class LeapAttachmentStore(object):
+
+    def __init__(self, soledad):
+        self.soledad = soledad
+
+    @defer.inlineCallbacks
+    def get_mail_attachment(self, attachment_id):
+        results = yield self.soledad.get_from_index('by-type-and-payloadhash', 'cnt', attachment_id) if attachment_id else []
+        if len(results):
+            content = ContentDocWrapper(**results[0].content)
+            defer.returnValue({'content-type': content.content_type, 'content': self._try_decode(
+                content.raw, content.content_transfer_encoding)})
+        else:
+            raise ValueError('No attachment with id %s found!' % attachment_id)
+
+    @defer.inlineCallbacks
+    def add_attachment(self, content, content_type):
+        cdoc = self._attachment_to_cdoc(content, content_type)
+        yield self.soledad.create_doc(cdoc.serialize(), doc_id=cdoc.phash)
+        defer.returnValue(cdoc.phash)
+
+    def _try_decode(self, raw, encoding):
+        encoding = encoding.lower()
+        if encoding == 'base64':
+            data = base64.decodestring(raw)
+        elif encoding == 'quoted-printable':
+            data = quopri.decodestring(raw)
+        else:
+            data = str(raw)
+
+        return bytearray(data)
+
+    def _attachment_to_cdoc(self, content, content_type, encoder=encoders.encode_base64):
+        major, sub = content_type.split('/')
+        attachment = MIMENonMultipart(major, sub)
+        attachment.set_payload(content)
+        encoder(attachment)
+        attachment.add_header('Content-Disposition', 'attachment', filename='does_not_matter.txt')
+
+        pseudo_mail = MIMEMultipart()
+        pseudo_mail.attach(attachment)
+
+        tmp_mail = SoledadMailAdaptor().get_msg_from_string(MessageClass=Message, raw_msg=pseudo_mail.as_string())
+
+        cdoc = tmp_mail.get_wrapper().cdocs[1]
+        return cdoc
+
+    def _calc_attachment_id_(self, content, content_type, encoder=encoders.encode_base64):
+        cdoc = self._attachment_to_cdoc(content, content_type, encoder)
+        return cdoc.phash
diff --git a/service/pixelated/adapter/mailstore/leap_mailstore.py b/service/pixelated/adapter/mailstore/leap_mailstore.py
index 14b0e417..2660a208 100644
--- a/service/pixelated/adapter/mailstore/leap_mailstore.py
+++ b/service/pixelated/adapter/mailstore/leap_mailstore.py
@@ -16,7 +16,6 @@
 import base64
 from email.header import decode_header
 from email.utils import parseaddr
-import quopri
 from uuid import uuid4
 
 import re
@@ -222,27 +221,6 @@ class LeapMailStore(MailStore):
         return defer.gatherResults(deferreds, consumeErrors=True)
 
     @defer.inlineCallbacks
-    def get_mail_attachment(self, attachment_id):
-        results = yield self.soledad.get_from_index('by-type-and-payloadhash', 'cnt', attachment_id) if attachment_id else []
-        if len(results):
-            content = ContentDocWrapper(**results[0].content)
-            defer.returnValue({'content-type': content.content_type, 'content': self._try_decode(
-                content.raw, content.content_transfer_encoding)})
-        else:
-            raise ValueError('No attachment with id %s found!' % attachment_id)
-
-    def _try_decode(self, raw, encoding):
-        encoding = encoding.lower()
-        if encoding == 'base64':
-            data = base64.decodestring(raw)
-        elif encoding == 'quoted-printable':
-            data = quopri.decodestring(raw)
-        else:
-            data = str(raw)
-
-        return bytearray(data)
-
-    @defer.inlineCallbacks
     def update_mail(self, mail):
         message = yield self._fetch_msg_from_soledad(mail.mail_id)
         message.get_wrapper().set_tags(tuple(mail.tags))
diff --git a/service/pixelated/adapter/services/mail_service.py b/service/pixelated/adapter/services/mail_service.py
index 4c1c1c0d..75c0808e 100644
--- a/service/pixelated/adapter/services/mail_service.py
+++ b/service/pixelated/adapter/services/mail_service.py
@@ -28,39 +28,20 @@ from leap.mail.adaptors.soledad import SoledadMailAdaptor
 
 class MailService(object):
 
-    def __init__(self, mail_sender, mail_store, search_engine, account_email):
+    def __init__(self, mail_sender, mail_store, search_engine, account_email, attachment_store):
         self.mail_store = mail_store
         self.search_engine = search_engine
         self.mail_sender = mail_sender
         self.account_email = account_email
+        self.attchment_store = attachment_store
 
     @defer.inlineCallbacks
     def all_mails(self):
         mails = yield self.mail_store.all_mails()
         defer.returnValue(mails)
 
-    def _attachment_to_cdoc(self, content, content_type, encoder=encoders.encode_base64):
-        major, sub = content_type.split('/')
-        attachment = MIMENonMultipart(major, sub)
-        attachment.set_payload(content)
-        encoder(attachment)
-        attachment.add_header('Content-Disposition', 'attachment', filename='does_not_matter.txt')
-
-        pseudo_mail = MIMEMultipart()
-        pseudo_mail.attach(attachment)
-
-        tmp_mail = SoledadMailAdaptor().get_msg_from_string(MessageClass=Message, raw_msg=pseudo_mail.as_string())
-
-        cdoc = tmp_mail.get_wrapper().cdocs[1]
-        return cdoc
-
-    def _calc_attachment_id_(self, content, content_type, encoder=encoders.encode_base64):
-        cdoc = self._attachment_to_cdoc(content, content_type, encoder)
-
-        return cdoc.phash
-
-    def attachment_id(self, content, content_type):
-        return self._calc_attachment_id_(content, content_type)
+    def save_attachment(self, content, content_type):
+        return self.attchment_store.add_attachment(content, content_type)
 
     @defer.inlineCallbacks
     def mails(self, query, window_size, page):
@@ -103,7 +84,7 @@ class MailService(object):
         return self.mail_store.get_mail(mail_id, include_body=True)
 
     def attachment(self, attachment_id):
-        return self.mail_store.get_mail_attachment(attachment_id)
+        return self.attchment_store.get_mail_attachment(attachment_id)
 
     @defer.inlineCallbacks
     def mail_exists(self, mail_id):
diff --git a/service/pixelated/config/services.py b/service/pixelated/config/services.py
index b70bb3f9..b8b355b0 100644
--- a/service/pixelated/config/services.py
+++ b/service/pixelated/config/services.py
@@ -1,3 +1,4 @@
+from pixelated.adapter.mailstore.leap_attachment_store import LeapAttachmentStore
 from pixelated.adapter.mailstore.searchable_mailstore import SearchableMailStore
 from pixelated.adapter.services.mail_service import MailService
 from pixelated.adapter.model.mail import InputMail
@@ -61,7 +62,8 @@ class Services(object):
             pixelated_mail_sender,
             leap_session.mail_store,
             search_engine,
-            leap_session.account_email())
+            leap_session.account_email(),
+            LeapAttachmentStore(leap_session.soledad))
 
     def setup_draft_service(self, mail_store):
         return DraftService(mail_store)
diff --git a/service/pixelated/resources/attachments_resource.py b/service/pixelated/resources/attachments_resource.py
index 911fc43d..05bc923f 100644
--- a/service/pixelated/resources/attachments_resource.py
+++ b/service/pixelated/resources/attachments_resource.py
@@ -90,7 +90,7 @@ class AttachmentsResource(Resource):
         fields = cgi.FieldStorage(fp=request.content, headers=(request.getAllHeaders()),
                                   environ={'REQUEST_METHOD': 'POST'})
         _file = fields['attachment']
-        deferred = defer.maybeDeferred(self.mail_service.attachment_id, _file.value, _file.type)
+        deferred = self.mail_service.save_attachment(_file.value, _file.type)
 
         def send_location(attachment_id):
             request.headers['Location'] = '/%s/%s' % (self.BASE_URL, attachment_id)
diff --git a/service/test/support/integration/app_test_client.py b/service/test/support/integration/app_test_client.py
index 5f7eb90a..89f42532 100644
--- a/service/test/support/integration/app_test_client.py
+++ b/service/test/support/integration/app_test_client.py
@@ -31,6 +31,7 @@ from twisted.internet import reactor, defer
 from twisted.internet.defer import succeed
 from twisted.web.resource import getChildForRequest
 # from twisted.web.server import Site as PixelatedSite
+from pixelated.adapter.mailstore.leap_attachment_store import LeapAttachmentStore
 from pixelated.adapter.services.feedback_service import FeedbackService
 from pixelated.config.site import PixelatedSite
 
@@ -70,6 +71,7 @@ class AppTestClient(object):
         self.mail_sender = self._create_mail_sender()
 
         self.mail_store = SearchableMailStore(LeapMailStore(self.soledad), self.search_engine)
+        self.attachment_store = LeapAttachmentStore(self.soledad)
 
         account_ready_cb = defer.Deferred()
         self.account = IMAPAccount(self.ACCOUNT, self.soledad, account_ready_cb)
@@ -78,7 +80,7 @@ class AppTestClient(object):
         self.leap_session = mock()
         self.feedback_service = FeedbackService(self.leap_session)
 
-        self.mail_service = self._create_mail_service(self.mail_sender, self.mail_store, self.search_engine)
+        self.mail_service = self._create_mail_service(self.mail_sender, self.mail_store, self.search_engine, self.attachment_store)
         mails = yield self.mail_service.all_mails()
         self.search_engine.index_mails(mails)
 
@@ -166,8 +168,8 @@ class AppTestClient(object):
         mail_sender.sendmail.side_effect = lambda mail: succeed(mail)
         return mail_sender
 
-    def _create_mail_service(self, mail_sender, mail_store, search_engine):
-        mail_service = MailService(mail_sender, mail_store, search_engine, self.MAIL_ADDRESS)
+    def _create_mail_service(self, mail_sender, mail_store, search_engine, attachment_store):
+        mail_service = MailService(mail_sender, mail_store, search_engine, self.MAIL_ADDRESS, attachment_store)
         return mail_service
 
     def _generate_soledad_test_folder_name(self, soledad_test_folder='/tmp/soledad-test/test'):
diff --git a/service/test/unit/adapter/mailstore/test_leap_attachment_store.py b/service/test/unit/adapter/mailstore/test_leap_attachment_store.py
new file mode 100644
index 00000000..172cceb6
--- /dev/null
+++ b/service/test/unit/adapter/mailstore/test_leap_attachment_store.py
@@ -0,0 +1,119 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (c) 2015 ThoughtWorks, Inc.
+#
+# Pixelated is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Pixelated is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY 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 Pixelated. If not, see <http://www.gnu.org/licenses/>.
+import json
+from uuid import uuid4
+
+from leap.mail.adaptors.soledad_indexes import MAIL_INDEXES
+from leap.soledad.common.document import SoledadDocument
+from mockito import mock, when, verify
+import test.support.mockito
+from twisted.internet import defer
+from twisted.trial.unittest import TestCase
+from leap.mail.adaptors.soledad import SoledadMailAdaptor, MailboxWrapper, ContentDocWrapper
+
+from pixelated.adapter.mailstore.leap_attachment_store import LeapAttachmentStore
+
+
+class TestLeapAttachmentStore(TestCase):
+    def setUp(self):
+        self.soledad = mock()
+        self.mbox_uuid = str(uuid4())
+        self.doc_by_id = {}
+        self.mbox_uuid_by_name = {}
+        self.mbox_soledad_docs = []
+
+        when(self.soledad).get_from_index('by-type', 'mbox').thenAnswer(lambda: defer.succeed(self.mbox_soledad_docs))
+        self._mock_get_mailbox('INBOX')
+
+    @defer.inlineCallbacks
+    def test_get_mail_attachment(self):
+        attachment_id = 'AAAA9AAD9E153D24265395203C53884506ABA276394B9FEC02B214BF9E77E48E'
+        doc = SoledadDocument(json=json.dumps({'content_type': 'foo/bar', 'raw': 'asdf'}))
+        when(self.soledad).get_from_index('by-type-and-payloadhash', 'cnt', attachment_id).thenReturn(defer.succeed([doc]))
+        store = LeapAttachmentStore(self.soledad)
+
+        attachment = yield store.get_mail_attachment(attachment_id)
+
+        self.assertEqual({'content-type': 'foo/bar', 'content': bytearray('asdf')}, attachment)
+
+    @defer.inlineCallbacks
+    def test_store_attachment(self):
+        content = 'this is some attachment content'
+        content_type = 'text/plain'
+        cdoc_serialized = {'content_transfer_encoding': 'base64', 'lkf': [], 'content_disposition': 'attachment',
+                           'ctype': '', 'raw': 'dGhpcyBpcyBzb21lIGF0dGFjaG1lbnQgY29udGVudA==',
+                           'phash': '9863729729D2E2EE8E52F0A7115CE33AD18DDA4B58E49AE08DD092D1C8E699B0',
+                           'content_type': 'text/plain', 'type': 'cnt'}
+
+        store = LeapAttachmentStore(self.soledad)
+
+        attachment_id = yield store.add_attachment(content, content_type)
+
+        self.assertEqual('9863729729D2E2EE8E52F0A7115CE33AD18DDA4B58E49AE08DD092D1C8E699B0', attachment_id)
+
+        verify(self.soledad).create_doc(cdoc_serialized, doc_id=attachment_id)
+
+    @defer.inlineCallbacks
+    def test_get_mail_attachment_different_content_encodings(self):
+        attachment_id = '1B0A9AAD9E153D24265395203C53884506ABA276394B9FEC02B214BF9E77E48E'
+        encoding_examples = [('', 'asdf', 'asdf'),
+                             ('base64', 'asdf', 'YXNkZg=='),
+                             ('quoted-printable', 'äsdf', '=C3=A4sdf')]
+
+        for transfer_encoding, data, encoded_data in encoding_examples:
+            doc = SoledadDocument(json=json.dumps({'content_type': 'foo/bar', 'raw': encoded_data,
+                                                   'content_transfer_encoding': transfer_encoding}))
+            when(self.soledad).get_from_index('by-type-and-payloadhash', 'cnt', attachment_id).thenReturn(defer.succeed([doc]))
+            store = LeapAttachmentStore(self.soledad)
+
+            attachment = yield store.get_mail_attachment(attachment_id)
+
+            self.assertEqual(bytearray(data), attachment['content'])
+
+    @defer.inlineCallbacks
+    def test_get_mail_attachment_throws_exception_if_attachment_does_not_exist(self):
+        attachment_id = '1B0A9AAD9E153D24265395203C53884506ABA276394B9FEC02B214BF9E77E48E'
+        when(self.soledad).get_from_index('by-type-and-payloadhash', 'cnt', attachment_id).thenReturn(defer.succeed([]))
+        store = LeapAttachmentStore(self.soledad)
+        try:
+            yield store.get_mail_attachment(attachment_id)
+            self.fail('ValueError exception expected')
+        except ValueError:
+            pass
+
+    def _mock_get_mailbox(self, mailbox_name, create_new_uuid=False):
+        mbox_uuid = self.mbox_uuid if not create_new_uuid else str(uuid4())
+        when(self.soledad).list_indexes().thenReturn(defer.succeed(MAIL_INDEXES)).thenReturn(
+            defer.succeed(MAIL_INDEXES))
+        doc_id = str(uuid4())
+        mbox = MailboxWrapper(doc_id=doc_id, mbox=mailbox_name, uuid=mbox_uuid)
+        soledad_doc = SoledadDocument(doc_id, json=json.dumps(mbox.serialize()))
+        when(self.soledad).get_from_index('by-type-and-mbox', 'mbox', mailbox_name).thenReturn(defer.succeed([soledad_doc]))
+        self._mock_get_soledad_doc(doc_id, mbox)
+
+        self.mbox_uuid_by_name[mailbox_name] = mbox_uuid
+        self.mbox_soledad_docs.append(soledad_doc)
+
+        return mbox, soledad_doc
+
+    def _mock_get_soledad_doc(self, doc_id, doc):
+        soledad_doc = SoledadDocument(doc_id, json=json.dumps(doc.serialize()))
+
+        # when(self.soledad).get_doc(doc_id).thenReturn(defer.succeed(soledad_doc))
+        when(self.soledad).get_doc(doc_id).thenAnswer(lambda: defer.succeed(soledad_doc))
+
+        self.doc_by_id[doc_id] = soledad_doc
diff --git a/service/test/unit/adapter/mailstore/test_leap_mailstore.py b/service/test/unit/adapter/mailstore/test_leap_mailstore.py
index 4eabc144..b5b6a742 100644
--- a/service/test/unit/adapter/mailstore/test_leap_mailstore.py
+++ b/service/test/unit/adapter/mailstore/test_leap_mailstore.py
@@ -135,45 +135,6 @@ class TestLeapMailStore(TestCase):
         self.assertEqual(expeted_body, mail.body)
 
     @defer.inlineCallbacks
-    def test_get_mail_attachment(self):
-        attachment_id = 'AAAA9AAD9E153D24265395203C53884506ABA276394B9FEC02B214BF9E77E48E'
-        doc = SoledadDocument(json=json.dumps({'content_type': 'foo/bar', 'raw': 'asdf'}))
-        when(self.soledad).get_from_index('by-type-and-payloadhash', 'cnt', attachment_id).thenReturn(defer.succeed([doc]))
-        store = LeapMailStore(self.soledad)
-
-        attachment = yield store.get_mail_attachment(attachment_id)
-
-        self.assertEqual({'content-type': 'foo/bar', 'content': bytearray('asdf')}, attachment)
-
-    @defer.inlineCallbacks
-    def test_get_mail_attachment_different_content_encodings(self):
-        attachment_id = '1B0A9AAD9E153D24265395203C53884506ABA276394B9FEC02B214BF9E77E48E'
-        encoding_examples = [('', 'asdf', 'asdf'),
-                             ('base64', 'asdf', 'YXNkZg=='),
-                             ('quoted-printable', 'äsdf', '=C3=A4sdf')]
-
-        for transfer_encoding, data, encoded_data in encoding_examples:
-            doc = SoledadDocument(json=json.dumps({'content_type': 'foo/bar', 'raw': encoded_data,
-                                                   'content_transfer_encoding': transfer_encoding}))
-            when(self.soledad).get_from_index('by-type-and-payloadhash', 'cnt', attachment_id).thenReturn(defer.succeed([doc]))
-            store = LeapMailStore(self.soledad)
-
-            attachment = yield store.get_mail_attachment(attachment_id)
-
-            self.assertEqual(bytearray(data), attachment['content'])
-
-    @defer.inlineCallbacks
-    def test_get_mail_attachment_throws_exception_if_attachment_does_not_exist(self):
-        attachment_id = '1B0A9AAD9E153D24265395203C53884506ABA276394B9FEC02B214BF9E77E48E'
-        when(self.soledad).get_from_index('by-type-and-payloadhash', 'cnt', attachment_id).thenReturn(defer.succeed([]))
-        store = LeapMailStore(self.soledad)
-        try:
-            yield store.get_mail_attachment(attachment_id)
-            self.fail('ValueError exception expected')
-        except ValueError:
-            pass
-
-    @defer.inlineCallbacks
     def test_update_mail(self):
         mdoc_id, fdoc_id = self._add_mail_fixture_to_soledad_from_file('mbox00000000')
         soledad_fdoc = self.doc_by_id[fdoc_id]
diff --git a/service/test/unit/adapter/test_mail_service.py b/service/test/unit/adapter/test_mail_service.py
index d14a0eb0..27c80fde 100644
--- a/service/test/unit/adapter/test_mail_service.py
+++ b/service/test/unit/adapter/test_mail_service.py
@@ -28,6 +28,7 @@ class TestMailService(unittest.TestCase):
     def setUp(self):
         self.drafts = mock()
         self.mail_store = mock()
+        self.attachment_store = mock()
         self.mailboxes = mock()
 
         self.mailboxes.drafts = defer.succeed(self.drafts)
@@ -37,7 +38,7 @@ class TestMailService(unittest.TestCase):
 
         self.mail_sender = mock()
         self.search_engine = mock()
-        self.mail_service = MailService(self.mail_sender, self.mail_store, self.search_engine, 'acount@email')
+        self.mail_service = MailService(self.mail_sender, self.mail_store, self.search_engine, 'acount@email', self.attachment_store)
 
     def tearDown(self):
         unstub()
@@ -158,7 +159,7 @@ class TestMailService(unittest.TestCase):
     @defer.inlineCallbacks
     def test_get_attachment(self):
         attachment_dict = {'content': bytearray('data'), 'content-type': 'text/plain'}
-        when(self.mail_store).get_mail_attachment('some attachment id').thenReturn(defer.succeed(attachment_dict))
+        when(self.attachment_store).get_mail_attachment('some attachment id').thenReturn(defer.succeed(attachment_dict))
 
         attachment = yield self.mail_service.attachment('some attachment id')
 
diff --git a/service/test/unit/resources/test_attachments_resource.py b/service/test/unit/resources/test_attachments_resource.py
index 837f5324..2afa208c 100644
--- a/service/test/unit/resources/test_attachments_resource.py
+++ b/service/test/unit/resources/test_attachments_resource.py
@@ -2,6 +2,7 @@ import json
 import unittest
 
 from mock import patch, MagicMock
+from mockito import mock, when, verify
 from twisted.internet import defer
 from twisted.web.test.requesthelper import DummyRequest
 
@@ -12,19 +13,22 @@ from test.unit.resources import DummySite
 class AttachmentsResourceTest(unittest.TestCase):
 
     def setUp(self):
-        self.mail_service = MagicMock()
+        self.mail_service = mock()
         self.mails_resource = AttachmentsResource(self.mail_service)
         self.mails_resource.isLeaf = True
         self.web = DummySite(self.mails_resource)
 
-    @patch('twisted.internet.defer.maybeDeferred')
     @patch('cgi.FieldStorage')
-    def test_post_new_attachment(self, mock_fields, mock_maybe_deferred):
+    def test_post_new_attachment(self, mock_fields):
         request = DummyRequest(['/attachment'])
         request.method = 'POST'
         request.content = 'mocked'
         attachment_id = 'B5B4ED80AC3B894523D72E375DACAA2FC6606C18EDF680FE95903086C8B5E14A'
-        mock_maybe_deferred.return_value = defer.succeed(attachment_id)
+        _file = MagicMock()
+        _file.value = 'some mocked value'
+        _file.type = 'some mocked type'
+        mock_fields.return_value = {'attachment': _file}
+        when(self.mail_service).save_attachment('some mocked value', 'some mocked type').thenReturn(defer.succeed(attachment_id))
 
         d = self.web.get(request)
 
@@ -32,24 +36,30 @@ class AttachmentsResourceTest(unittest.TestCase):
             self.assertEqual(201, request.code)
             self.assertEqual('/attachment/%s' % attachment_id, request.headers['Location'])
             self.assertEqual({'attachment_id': attachment_id}, json.loads(request.written[0]))
+            verify(self.mail_service).save_attachment('some mocked value', 'some mocked type')
 
         d.addCallback(assert_response)
         return d
 
-    @patch('twisted.internet.defer.maybeDeferred')
     @patch('cgi.FieldStorage')
-    def test_post_attachment_fails(self, mock_fields, mock_maybe_deferred):
-        mock_maybe_deferred.return_value = defer.fail(Exception)
+    def test_post_attachment_fails(self, mock_fields):
         request = DummyRequest(['/attachment'])
         request.method = 'POST'
         request.content = 'mocked'
 
+        _file = MagicMock()
+        _file.value = 'some mocked value'
+        _file.type = 'some mocked type'
+        mock_fields.return_value = {'attachment': _file}
+        when(self.mail_service).save_attachment('some mocked value', 'some mocked type').thenReturn(defer.fail(Exception))
+
         d = self.web.get(request)
 
         def assert_response(_):
             self.assertEqual(500, request.code)
             self.assertFalse('Location' in request.headers)
             self.assertEqual({"message": "Something went wrong. Attachement not saved."}, json.loads(request.written[0]))
+            verify(self.mail_service).save_attachment('some mocked value', 'some mocked type')
 
         d.addCallback(assert_response)
         return d