django-anymail/tests/test_mailjet_backend.py

# -*- coding: utf-8 -*-

from base64 import b64encode
from decimal import Decimal
from email.mime.base import MIMEBase
from email.mime.image import MIMEImage

from django.core import mail
from django.core.exceptions import ImproperlyConfigured
from django.test import SimpleTestCase
from django.test.utils import override_settings

from anymail.exceptions import (AnymailAPIError, AnymailSerializationError,
                                AnymailUnsupportedFeature,
                                AnymailRequestsAPIError)
from anymail.message import attach_inline_image_file

from .mock_requests_backend import RequestsBackendMockAPITestCase, SessionSharingTestCasesMixin
from .utils import sample_image_content, sample_image_path, SAMPLE_IMAGE_FILENAME, AnymailTestMixin, decode_att


@override_settings(EMAIL_BACKEND='anymail.backends.mailjet.EmailBackend',
                   ANYMAIL={
                       'MAILJET_API_KEY': '',
                       'MAILJET_SECRET_KEY': ''
                   })
class MailjetBackendMockAPITestCase(RequestsBackendMockAPITestCase):
    DEFAULT_RAW_RESPONSE = b"""{
        "Sent": [{
            "Email": "to@example.com",
            "MessageID": 12345678901234567
        }]
    }"""

    DEFAULT_TEMPLATE_RESPONSE = b"""{
        "Count": 1,
        "Data": [{
            "Text-part": "text body",
            "Html-part": "html body",
            "MJMLContent": "",
            "Headers": {
                "Subject": "Hello World!",
                "SenderName": "Friendly Tester",
                "SenderEmail": "some@example.com",
                "ReplyEmail": ""
            }
        }],
        "Total": 1
    }"""

    def setUp(self):
        super(MailjetBackendMockAPITestCase, self).setUp()
        # Simple message useful for many tests
        self.message = mail.EmailMultiAlternatives('Subject', 'Text Body', 'from@example.com', ['to@example.com'])

    def set_template_response(self, status_code=200, raw=None):
        """Sets an expectation for a template and populate its response."""
        if raw is None:
            raw = self.DEFAULT_TEMPLATE_RESPONSE
        template_response = RequestsBackendMockAPITestCase.MockResponse(status_code, raw)
        self.mock_request.side_effect = iter([
            template_response,
            self.mock_request.return_value
        ])


class MailjetBackendStandardEmailTests(MailjetBackendMockAPITestCase):
    """Test backend support for Django standard email features"""

    def test_send_mail(self):
        """Test basic API for simple send"""
        mail.send_mail('Subject here', 'Here is the message.',
                       'from@sender.example.com', ['to@example.com'], fail_silently=False)
        self.assert_esp_called('/v3/send')
        data = self.get_api_call_json()
        self.assertEqual(data['Subject'], "Subject here")
        self.assertEqual(data['Text-part'], "Here is the message.")
        self.assertEqual(data['FromEmail'], "from@sender.example.com")
        self.assertEqual(data['Recipients'], [{"Email": "to@example.com"}])

    def test_name_addr(self):
        """Make sure RFC2822 name-addr format (with display-name) is allowed

        (Test both sender and recipient addresses)
        """
        msg = mail.EmailMessage(
            'Subject', 'Message', 'From Name <from@example.com>',
            ['Recipient #1 <to1@example.com>', 'to2@example.com'],
            cc=['Carbon Copy <cc1@example.com>', 'cc2@example.com'],
            bcc=['Blind Copy <bcc1@example.com>', 'bcc2@example.com'])
        msg.send()
        data = self.get_api_call_json()
        # See https://dev.mailjet.com/guides/#sending-a-basic-email
        self.assertEqual(data['FromName'], 'From Name')
        self.assertEqual(data['FromEmail'], 'from@example.com')
        self.assertEqual(data['To'], 'Recipient #1 <to1@example.com>, to2@example.com')
        self.assertEqual(data['Cc'], 'Carbon Copy <cc1@example.com>, cc2@example.com')
        self.assertEqual(data['Bcc'], 'Blind Copy <bcc1@example.com>, bcc2@example.com')

    def test_comma_in_display_name(self):
        # note there are two paths: with cc/bcc, and without
        msg = mail.EmailMessage(
            'Subject', 'Message', '"Example, Inc." <from@example.com>',
            ['"Recipient, Ltd." <to@example.com>'])
        msg.send()
        data = self.get_api_call_json()
        self.assertEqual(data['FromName'], 'Example, Inc.')
        self.assertEqual(data['FromEmail'], 'from@example.com')
        self.assertEqual(data['Recipients'][0]["Email"], "to@example.com")
        self.assertEqual(data['Recipients'][0]["Name"], "Recipient, Ltd.")  # separate Name field works fine

        # Mailjet 3.0 API doesn't properly parse RFC-2822 quoted display-names from To/Cc/Bcc:
        # `To: "Recipient, Ltd." <to@example.com>` tries to send messages to `"Recipient`
        # and to `Ltd.` (neither of which are actual email addresses).
        # As a workaround, force MIME "encoded-word" utf-8 encoding, which gets past Mailjet's broken parsing.
        # (This shouldn't be necessary in Mailjet 3.1, where Name becomes a separate json field for Cc/Bcc.)
        msg.cc = ['cc@example.com']
        msg.send()
        data = self.get_api_call_json()
        # self.assertEqual(data['To'], '"Recipient, Ltd." <to@example.com>')  # this doesn't work
        self.assertEqual(data['To'], '=?utf-8?q?Recipient=2C_Ltd=2E?= <to@example.com>')  # workaround

    def test_email_message(self):
        email = mail.EmailMessage(
            'Subject', 'Body goes here', 'from@example.com',
            ['to1@example.com', 'Also To <to2@example.com>'],
            bcc=['bcc1@example.com', 'Also BCC <bcc2@example.com>'],
            cc=['cc1@example.com', 'Also CC <cc2@example.com>'],
            headers={'Reply-To': 'another@example.com',
                     'X-MyHeader': 'my value'})
        email.send()
        data = self.get_api_call_json()
        self.assertEqual(data['Subject'], "Subject")
        self.assertEqual(data['Text-part'], "Body goes here")
        self.assertEqual(data['FromEmail'], "from@example.com")
        self.assertEqual(data['To'], 'to1@example.com, Also To <to2@example.com>')
        self.assertEqual(data['Bcc'], 'bcc1@example.com, Also BCC <bcc2@example.com>')
        self.assertEqual(data['Cc'], 'cc1@example.com, Also CC <cc2@example.com>')
        self.assertCountEqual(data['Headers'], {
            'Reply-To': 'another@example.com',
            'X-MyHeader': 'my value',
        })

    def test_html_message(self):
        text_content = 'This is an important message.'
        html_content = '<p>This is an <strong>important</strong> message.</p>'
        email = mail.EmailMultiAlternatives('Subject', text_content,
                                            'from@example.com', ['to@example.com'])
        email.attach_alternative(html_content, "text/html")
        email.send()
        data = self.get_api_call_json()
        self.assertEqual(data['Text-part'], text_content)
        self.assertEqual(data['Html-part'], html_content)
        # Don't accidentally send the html part as an attachment:
        self.assertNotIn('Attachments', data)

    def test_html_only_message(self):
        html_content = '<p>This is an <strong>important</strong> message.</p>'
        email = mail.EmailMessage('Subject', html_content, 'from@example.com', ['to@example.com'])
        email.content_subtype = "html"  # Main content is now text/html
        email.send()
        data = self.get_api_call_json()
        self.assertNotIn('Text-part', data)
        self.assertEqual(data['Html-part'], html_content)

    def test_extra_headers(self):
        self.message.extra_headers = {'X-Custom': 'string', 'X-Num': 123}
        self.message.send()
        data = self.get_api_call_json()
        self.assertCountEqual(data['Headers'], {
            'X-Custom': 'string',
            'X-Num': 123,
        })

    def test_extra_headers_serialization_error(self):
        self.message.extra_headers = {'X-Custom': Decimal(12.5)}
        with self.assertRaisesMessage(AnymailSerializationError, "Decimal"):
            self.message.send()

    def test_reply_to(self):
        email = mail.EmailMessage('Subject', 'Body goes here', 'from@example.com', ['to1@example.com'],
                                  reply_to=['reply@example.com', 'Other <reply2@example.com>'],
                                  headers={'X-Other': 'Keep'})
        email.send()
        data = self.get_api_call_json()
        self.assertEqual(data['Headers'], {
            'Reply-To': 'reply@example.com, Other <reply2@example.com>',
            'X-Other': 'Keep'
        })  # don't lose other headers

    def test_attachments(self):
        text_content = "* Item one\n* Item two\n* Item three"
        self.message.attach(filename="test.txt", content=text_content, mimetype="text/plain")

        # Should guess mimetype if not provided...
        png_content = b"PNG\xb4 pretend this is the contents of a png file"
        self.message.attach(filename="test.png", content=png_content)

        # Should work with a MIMEBase object (also tests no filename)...
        pdf_content = b"PDF\xb4 pretend this is valid pdf data"
        mimeattachment = MIMEBase('application', 'pdf')
        mimeattachment.set_payload(pdf_content)
        self.message.attach(mimeattachment)

        self.message.send()
        data = self.get_api_call_json()
        attachments = data['Attachments']
        self.assertEqual(len(attachments), 3)
        self.assertEqual(attachments[0]["Filename"], "test.txt")
        self.assertEqual(attachments[0]["Content-type"], "text/plain")
        self.assertEqual(decode_att(attachments[0]["content"]).decode('ascii'), text_content)
        self.assertNotIn('ContentID', attachments[0])

        self.assertEqual(attachments[1]["Content-type"], "image/png")  # inferred from filename
        self.assertEqual(attachments[1]["Filename"], "test.png")
        self.assertEqual(decode_att(attachments[1]["content"]), png_content)
        self.assertNotIn('ContentID', attachments[1])  # make sure image not treated as inline

        self.assertEqual(attachments[2]["Content-type"], "application/pdf")
        self.assertEqual(attachments[2]["Filename"], "")  # none
        self.assertEqual(decode_att(attachments[2]["content"]), pdf_content)
        self.assertNotIn('ContentID', attachments[2])

    def test_unicode_attachment_correctly_decoded(self):
        self.message.attach(u"Une pièce jointe.html", u'<p>\u2019</p>', mimetype='text/html')
        self.message.send()
        data = self.get_api_call_json()
        self.assertEqual(data['Attachments'], [{
            'Filename': u'Une pièce jointe.html',
            'Content-type': 'text/html',
            'content': b64encode(u'<p>\u2019</p>'.encode('utf-8')).decode('ascii')
        }])

    def test_embedded_images(self):
        image_filename = SAMPLE_IMAGE_FILENAME
        image_path = sample_image_path(image_filename)
        image_data = sample_image_content(image_filename)

        cid = attach_inline_image_file(self.message, image_path)  # Read from a png file
        html_content = '<p>This has an <img src="cid:%s" alt="inline" /> image.</p>' % cid
        self.message.attach_alternative(html_content, "text/html")

        self.message.send()
        data = self.get_api_call_json()
        self.assertEqual(data['Html-part'], html_content)

        attachments = data['Inline_attachments']
        self.assertEqual(len(attachments), 1)
        self.assertEqual(attachments[0]['Filename'], cid)
        self.assertEqual(attachments[0]['Content-type'], 'image/png')
        self.assertEqual(decode_att(attachments[0]["content"]), image_data)

    def test_attached_images(self):
        image_filename = SAMPLE_IMAGE_FILENAME
        image_path = sample_image_path(image_filename)
        image_data = sample_image_content(image_filename)

        self.message.attach_file(image_path)  # option 1: attach as a file

        image = MIMEImage(image_data)  # option 2: construct the MIMEImage and attach it directly
        self.message.attach(image)

        image_data_b64 = b64encode(image_data).decode('ascii')

        self.message.send()
        data = self.get_api_call_json()
        self.assertEqual(data['Attachments'], [
            {
                'Filename': image_filename,  # the named one
                'Content-type': 'image/png',
                'content': image_data_b64,
            },
            {
                'Filename': '',  # the unnamed one
                'Content-type': 'image/png',
                'content': image_data_b64,
            },
        ])

    def test_multiple_html_alternatives(self):
        # Multiple alternatives not allowed
        self.message.attach_alternative("<p>First html is OK</p>", "text/html")
        self.message.attach_alternative("<p>But not second html</p>", "text/html")
        with self.assertRaises(AnymailUnsupportedFeature):
            self.message.send()

    def test_html_alternative(self):
        # Only html alternatives allowed
        self.message.attach_alternative("{'not': 'allowed'}", "application/json")
        with self.assertRaises(AnymailUnsupportedFeature):
            self.message.send()

    def test_alternatives_fail_silently(self):
        # Make sure fail_silently is respected
        self.message.attach_alternative("{'not': 'allowed'}", "application/json")
        sent = self.message.send(fail_silently=True)
        self.assert_esp_not_called("API should not be called when send fails silently")
        self.assertEqual(sent, 0)

    def test_suppress_empty_address_lists(self):
        """Empty to, cc, bcc, and reply_to shouldn't generate empty fields"""
        self.message.send()
        data = self.get_api_call_json()
        self.assertNotIn('Cc', data)
        self.assertNotIn('Bcc', data)
        self.assertNotIn('ReplyTo', data)

        # Test empty `to` -- but send requires at least one recipient somewhere (like cc)
        self.message.to = []
        self.message.cc = ['cc@example.com']
        self.message.send()
        data = self.get_api_call_json()
        self.assertNotIn('To', data)
        self.assertEqual(data['Cc'], 'cc@example.com')

    def test_api_failure(self):
        self.set_mock_response(status_code=500)
        with self.assertRaisesMessage(AnymailAPIError, "Mailjet API response 500"):
            mail.send_mail('Subject', 'Body', 'from@example.com', ['to@example.com'])

        # Make sure fail_silently is respected
        self.set_mock_response(status_code=500)
        sent = mail.send_mail('Subject', 'Body', 'from@example.com', ['to@example.com'], fail_silently=True)
        self.assertEqual(sent, 0)

    def test_api_error_includes_details(self):
        """AnymailAPIError should include ESP's error message"""
        # JSON error response:
        error_response = b"""{
            "ErrorCode": 451,
            "Message": "Helpful explanation from Mailjet."
        }"""
        self.set_mock_response(status_code=200, raw=error_response)
        with self.assertRaisesMessage(AnymailAPIError, "Helpful explanation from Mailjet"):
            self.message.send()

        # Non-JSON error response:
        self.set_mock_response(status_code=500, raw=b"Ack! Bad proxy!")
        with self.assertRaisesMessage(AnymailAPIError, "Ack! Bad proxy!"):
            self.message.send()

        # No content in the error response:
        self.set_mock_response(status_code=502, raw=None)
        with self.assertRaises(AnymailAPIError):
            self.message.send()

    def test_invalid_api_key(self):
        """Anymail should add a helpful message for an invalid API key"""
        # Mailjet just returns a 401 error -- without additional explanation --
        # for invalid keys. We want to provide users something more helpful
        # than just "Mailjet API response 401:
        self.set_mock_response(status_code=401, reason="Unauthorized", raw=None)
        with self.assertRaisesMessage(AnymailAPIError, "Invalid Mailjet API key or secret"):
            self.message.send()


class MailjetBackendAnymailFeatureTests(MailjetBackendMockAPITestCase):
    """Test backend support for Anymail added features"""

    def test_envelope_sender(self):
        self.message.envelope_sender = "bounce-handler@bounces.example.com"
        self.message.send()
        data = self.get_api_call_json()
        self.assertEqual(data['Sender'], "bounce-handler@bounces.example.com")

    def test_metadata(self):
        # Mailjet expects the payload to be a single string
        # https://dev.mailjet.com/guides/#tagging-email-messages
        self.message.metadata = {'user_id': "12345", 'items': 6}
        self.message.send()
        data = self.get_api_call_json()
        self.assertJSONEqual(data['Mj-EventPayLoad'], {"user_id": "12345", "items": 6})

    def test_send_at(self):
        self.message.send_at = 1651820889  # 2022-05-06 07:08:09 UTC
        with self.assertRaisesMessage(AnymailUnsupportedFeature, 'send_at'):
            self.message.send()

    def test_tags(self):
        self.message.tags = ["receipt"]
        self.message.send()
        data = self.get_api_call_json()
        self.assertEqual(data['Mj-campaign'], "receipt")

        self.message.tags = ["receipt", "repeat-user"]
        with self.assertRaisesMessage(AnymailUnsupportedFeature, 'multiple tags'):
            self.message.send()

    def test_track_opens(self):
        self.message.track_opens = True
        self.message.send()
        data = self.get_api_call_json()
        self.assertEqual(data['Mj-trackopen'], 2)

    def test_track_clicks(self):
        self.message.track_clicks = True
        self.message.send()
        data = self.get_api_call_json()
        self.assertEqual(data['Mj-trackclick'], 2)

        # Also explicit "None" for False (to override server default)
        self.message.track_clicks = False
        self.message.send()
        data = self.get_api_call_json()
        self.assertEqual(data['Mj-trackclick'], 1)

    def test_template(self):
        # template_id can be str or int (but must be numeric ID -- not the template's name)
        self.message.template_id = '1234567'
        self.message.merge_global_data = {'name': "Alice", 'group': "Developers"}
        self.message.send()
        data = self.get_api_call_json()
        self.assertEqual(data['Mj-TemplateID'], '1234567')
        self.assertEqual(data['Vars'], {'name': "Alice", 'group': "Developers"})

    def test_template_populate_from_sender(self):
        self.set_template_response()
        self.message.template_id = '1234567'
        self.message.from_email = None
        self.message.send()
        data = self.get_api_call_json()
        self.assertEqual(data['Mj-TemplateID'], '1234567')
        self.assertEqual(data['FromName'], 'Friendly Tester')
        self.assertEqual(data['FromEmail'], 'some@example.com')

    def test_template_populate_from(self):
        # Note: Mailjet fails to properly quote the From field's display-name
        # if the template sender name contains commas (as shown here):
        template_response_content = b'''{
            "Count": 1,
            "Data": [{
                "Text-part": "text body",
                "Html-part": "html body",
                "MJMLContent": "",
                "Headers": {
                    "Subject": "Hello World!!",
                    "From": "Widgets, Inc. <noreply@example.com>",
                    "Reply-To": ""
                }
            }],
            "Total": 1
        }'''
        self.set_template_response(raw=template_response_content)
        self.message.template_id = '1234568'
        self.message.from_email = None
        self.message.send()
        data = self.get_api_call_json()
        self.assertEqual(data['Mj-TemplateID'], '1234568')
        self.assertEqual(data['FromName'], 'Widgets, Inc.')
        self.assertEqual(data['FromEmail'], 'noreply@example.com')

    def test_template_not_found(self):
        template_response_content = b'''{
            "ErrorInfo": "",
            "ErrorMessage": "Object not found",
            "StatusCode": 404
        }'''
        self.set_template_response(status_code=404, raw=template_response_content)
        self.message.template_id = '1234560'
        self.message.from_email = None
        with self.assertRaises(AnymailRequestsAPIError):
            self.message.send()

    def test_template_unexpected_response(self):
        # Missing headers (not sure if possible though).
        template_response_content = b'''{
            "Count": 1,
            "Data": [{
                "Text-part": "text body",
                "Html-part": "html body",
                "MJMLContent": "",
                "Headers": {
                }
            }],
            "Total": 1
        }'''
        self.set_template_response(raw=template_response_content)
        self.message.template_id = '1234561'
        self.message.from_email = None
        with self.assertRaisesMessage(AnymailRequestsAPIError, "template API"):
            self.message.send()

    def test_template_invalid_response(self):
        """Test scenario when MJ service returns no JSON for some reason."""
        template_response_content = b'''total garbage'''
        self.set_template_response(raw=template_response_content)
        self.message.template_id = '1234562'
        self.message.from_email = None
        with self.assertRaisesMessage(AnymailRequestsAPIError, "Invalid JSON"):
            self.message.send()

    def test_merge_data(self):
        self.message.to = ['alice@example.com']
        self.message.template_id = '1234567'
        self.message.merge_data = {
            'alice@example.com': {'name': "Alice", 'group': "Developers"},
        }
        self.message.send()
        data = self.get_api_call_json()
        self.assertEqual(data['Mj-TemplateID'], '1234567')
        self.assertNotIn('Vars', data)
        self.assertEqual(data['Recipients'], [{
            'Email': 'alice@example.com',
            'Vars': {'name': "Alice", 'group': "Developers"}
        }])

    def test_default_omits_options(self):
        """Make sure by default we don't send any ESP-specific options.

        Options not specified by the caller should be omitted entirely from
        the API call (*not* sent as False or empty). This ensures
        that your ESP account settings apply by default.
        """
        self.message.send()
        data = self.get_api_call_json()
        self.assertNotIn('Mj-campaign', data)
        self.assertNotIn('Mj-EventPayLoad', data)
        self.assertNotIn('Mj-TemplateID', data)
        self.assertNotIn('Vars', data)
        self.assertNotIn('Mj-trackopen', data)
        self.assertNotIn('Mj-trackclick', data)

    def test_esp_extra(self):
        self.message.esp_extra = {
            'MJ-TemplateErrorDeliver': True,
            'MJ-TemplateErrorReporting': 'bugs@example.com'
        }
        self.message.send()
        data = self.get_api_call_json()
        self.assertEqual(data['MJ-TemplateErrorDeliver'], True)
        self.assertEqual(data['MJ-TemplateErrorReporting'], 'bugs@example.com')

    # noinspection PyUnresolvedReferences
    def test_send_attaches_anymail_status(self):
        """ The anymail_status should be attached to the message when it is sent """
        response_content = b"""{
            "Sent": [{
                "Email": "to1@example.com",
                "MessageID": 12345678901234500
            }]
        }"""
        self.set_mock_response(raw=response_content)
        msg = mail.EmailMessage('Subject', 'Message', 'from@example.com', ['to1@example.com'],)
        sent = msg.send()
        self.assertEqual(sent, 1)
        self.assertEqual(msg.anymail_status.status, {'sent'})
        self.assertEqual(msg.anymail_status.message_id, "12345678901234500")
        self.assertEqual(msg.anymail_status.recipients['to1@example.com'].status, 'sent')
        self.assertEqual(msg.anymail_status.recipients['to1@example.com'].message_id, "12345678901234500")
        self.assertEqual(msg.anymail_status.esp_response.content, response_content)

    # noinspection PyUnresolvedReferences
    def test_status_includes_all_recipients(self):
        """The status should include an entry for each recipient"""
        # Note that Mailjet's response only communicates "Sent" status; not failed addresses.
        # (This is an example response from before the workaround for commas in display-names...)
        response_content = b"""{
            "Sent": [{
                "Email": "to1@example.com",
                "MessageID": 12345678901234500
            }, {
                "Email": "\\"Recipient",
                "MessageID": 12345678901234501
            }, {
                "Email": "Also",
                "MessageID": 12345678901234502
            }]
        }"""
        self.set_mock_response(raw=response_content)
        msg = mail.EmailMessage('Subject', 'Message', 'from@example.com',
                                ['to1@example.com', '"Recipient, Also" <to2@example.com>'],)
        sent = msg.send()
        self.assertEqual(sent, 1)
        self.assertEqual(msg.anymail_status.status, {'sent', 'unknown'})
        self.assertEqual(msg.anymail_status.recipients['to1@example.com'].status, 'sent')
        self.assertEqual(msg.anymail_status.recipients['to1@example.com'].message_id, "12345678901234500")
        self.assertEqual(msg.anymail_status.recipients['to2@example.com'].status, 'unknown')  # because, whoops
        self.assertEqual(msg.anymail_status.recipients['to2@example.com'].message_id, None)
        self.assertEqual(msg.anymail_status.message_id,
                         {"12345678901234500", "12345678901234501", "12345678901234502", None})
        self.assertEqual(msg.anymail_status.esp_response.content, response_content)

    # noinspection PyUnresolvedReferences
    def test_send_failed_anymail_status(self):
        """ If the send fails, anymail_status should contain initial values"""
        self.set_mock_response(status_code=500)
        sent = self.message.send(fail_silently=True)
        self.assertEqual(sent, 0)
        self.assertIsNone(self.message.anymail_status.status)
        self.assertIsNone(self.message.anymail_status.message_id)
        self.assertEqual(self.message.anymail_status.recipients, {})
        self.assertIsNone(self.message.anymail_status.esp_response)

    # noinspection PyUnresolvedReferences
    def test_send_unparsable_response(self):
        """If the send succeeds, but a non-JSON API response, should raise an API exception"""
        mock_response = self.set_mock_response(status_code=200,
                                               raw=b"yikes, this isn't a real response")
        with self.assertRaises(AnymailAPIError):
            self.message.send()
        self.assertIsNone(self.message.anymail_status.status)
        self.assertIsNone(self.message.anymail_status.message_id)
        self.assertEqual(self.message.anymail_status.recipients, {})
        self.assertEqual(self.message.anymail_status.esp_response, mock_response)

    def test_json_serialization_errors(self):
        """Try to provide more information about non-json-serializable data"""
        self.message.tags = [Decimal('19.99')]  # yeah, don't do this
        with self.assertRaises(AnymailSerializationError) as cm:
            self.message.send()
            print(self.get_api_call_json())
        err = cm.exception
        self.assertIsInstance(err, TypeError)  # compatibility with json.dumps
        self.assertIn("Don't know how to send this data to Mailjet", str(err))  # our added context
        self.assertRegex(str(err), r"Decimal.*is not JSON serializable")  # original message

    def test_merge_data_null_values(self):
        # Mailjet doesn't accept None (null) as a merge value;
        # returns "HTTP/1.1 500 Cannot convert data from Null value"
        self.message.merge_global_data = {'Some': None}
        self.set_mock_response(status_code=500, reason="Cannot convert data from Null value", raw=None)
        with self.assertRaisesMessage(AnymailAPIError, "Cannot convert data from Null value"):
            self.message.send()


class MailjetBackendSessionSharingTestCase(SessionSharingTestCasesMixin, MailjetBackendMockAPITestCase):
    """Requests session sharing tests"""
    pass  # tests are defined in the mixin


@override_settings(EMAIL_BACKEND="anymail.backends.mailjet.EmailBackend")
class MailjetBackendImproperlyConfiguredTests(SimpleTestCase, AnymailTestMixin):
    """Test ESP backend without required settings in place"""

    def test_missing_api_key(self):
        with self.assertRaises(ImproperlyConfigured) as cm:
            mail.send_mail('Subject', 'Message', 'from@example.com', ['to@example.com'])
        errmsg = str(cm.exception)
        self.assertRegex(errmsg, r'\bMAILJET_API_KEY\b')

    @override_settings(ANYMAIL={'MAILJET_API_KEY': 'dummy'})
    def test_missing_secret_key(self):
        with self.assertRaises(ImproperlyConfigured) as cm:
            mail.send_mail('Subject', 'Message', 'from@example.com', ['to@example.com'])
        errmsg = str(cm.exception)
        self.assertRegex(errmsg, r'\bMAILJET_SECRET_KEY\b')