Send invitation email when invite is created

src/registrar/models/domain_application.py

@@ -469,7 +469,9 @@ class DomainApplication(TimeStampedModel):
         nothing.
         """
         if self.submitter is None or self.submitter.email is None:
-            logger.warning("Cannot send confirmation email, no submitter email address.")
+            logger.warning(
+                "Cannot send confirmation email, no submitter email address."
+            )
             return
         try:
             send_templated_email(

src/registrar/templates/emails/domain_invitation.txt

@@ -0,0 +1,6 @@
+You have been invited to manage a domain on get.gov, the registrar for
+.gov domain names.
+
+To accept your invitation, go to <{{ domain_url }}>.
+
+You will need to log in with a Login.gov account using this email address.

src/registrar/tests/test_views.py

@@ -1,4 +1,5 @@
 from unittest import skip
+from unittest.mock import MagicMock, ANY
 
 from django.conf import settings
 from django.test import Client, TestCase
@@ -557,9 +558,7 @@ class DomainApplicationTests(TestWithUser, WebTest):
         # the post request should return a redirect to the contact
         # question
         self.assertEqual(election_result.status_code, 302)
-        self.assertEqual(
-            election_result["Location"], "/register/organization_contact/"
-        )
+        self.assertEqual(election_result["Location"], "/register/organization_contact/")
         self.app.set_cookie(settings.SESSION_COOKIE_NAME, session_id)
         contact_page = election_result.follow()
         self.assertNotContains(contact_page, "Federal agency")
@@ -1139,8 +1138,13 @@ class TestDomainDetail(TestWithDomainPermissions, WebTest):
         success_page = success_result.follow()
         self.assertContains(success_page, "mayor@igorville.gov")
 
+    @boto3_mocking.patching
     def test_domain_invitation_created(self):
-        """Add user on a nonexistent email creates an invitation."""
+        """Add user on a nonexistent email creates an invitation.
+
+        Adding a non-existent user sends an email as a side-effect, so mock
+        out the boto3 SES email sending here.
+        """
         # make sure there is no user with this email
         EMAIL = "mayor@igorville.gov"
         User.objects.filter(email=EMAIL).delete()
@@ -1159,10 +1163,36 @@ class TestDomainDetail(TestWithDomainPermissions, WebTest):
         self.assertContains(success_page, "Cancel")  # link to cancel invitation
         self.assertTrue(DomainInvitation.objects.filter(email=EMAIL).exists())
 
+    @boto3_mocking.patching
+    def test_domain_invitation_email_sent(self):
+        """Inviting a non-existent user sends them an email."""
+        # make sure there is no user with this email
+        EMAIL = "mayor@igorville.gov"
+        User.objects.filter(email=EMAIL).delete()
+
+        mock_client = MagicMock()
+        mock_client_instance = mock_client.return_value
+        with boto3_mocking.clients.handler_for("sesv2", mock_client):
+            add_page = self.app.get(
+                reverse("domain-users-add", kwargs={"pk": self.domain.id})
+            )
+            session_id = self.app.cookies[settings.SESSION_COOKIE_NAME]
+            add_page.form["email"] = EMAIL
+            self.app.set_cookie(settings.SESSION_COOKIE_NAME, session_id)
+            add_page.form.submit()
+        # check the mock instance to see if `send_email` was called right
+        mock_client_instance.send_email.assert_called_once_with(
+            FromEmailAddress=settings.DEFAULT_FROM_EMAIL,
+            Destination={"ToAddresses": [EMAIL]},
+            Content=ANY,
+        )
+
     def test_domain_invitation_cancel(self):
         """Posting to the delete view deletes an invitation."""
         EMAIL = "mayor@igorville.gov"
-        invitation, _ = DomainInvitation.objects.get_or_create(domain=self.domain, email=EMAIL)
+        invitation, _ = DomainInvitation.objects.get_or_create(
+            domain=self.domain, email=EMAIL
+        )
         self.client.post(reverse("invitation-delete", kwargs={"pk": invitation.id}))
         with self.assertRaises(DomainInvitation.DoesNotExist):
             DomainInvitation.objects.get(id=invitation.id)

src/registrar/views/domain.py

@@ -11,6 +11,7 @@ from django.views.generic.edit import DeleteView, FormMixin
 from registrar.models import Domain, DomainInvitation, User, UserDomainRole
 
 from ..forms import DomainAddUserForm
+from ..utility.email import send_templated_email, EmailSendingError
 from .utility import DomainPermission
 
 
@@ -56,6 +57,12 @@ class DomainAddUserView(DomainPermission, FormMixin, DetailView):
         else:
             return self.form_invalid(form)
 
+    def _domain_abs_url(self):
+        """Get an absolute URL for this domain."""
+        return self.request.build_absolute_uri(
+            reverse("domain", kwargs={"pk": self.object.id})
+        )
+
     def _make_invitation(self, email_address):
         """Make a Domain invitation for this email and redirect with a message."""
         invitation, created = DomainInvitation.objects.get_or_create(
@@ -68,7 +75,19 @@ class DomainAddUserView(DomainPermission, FormMixin, DetailView):
                 f"{email_address} has already been invited to this domain.",
             )
         else:
-            messages.success(self.request, f"Invited {email_address} to this domain.")
+            # created a new invitation in the database, so send an email
+            try:
+                send_templated_email(
+                    "emails/domain_invitation.txt",
+                    to_address=email_address,
+                    context={"domain_url": self._domain_abs_url()},
+                )
+            except EmailSendingError:
+                messages.warning(self.request, "Could not send email invitation.")
+            else:
+                messages.success(
+                    self.request, f"Invited {email_address} to this domain."
+                )
         return redirect(self.get_success_url())
 
     def form_valid(self, form):