✨(mailboxes) cannot create mailbox with same local part as alias

should not be able to create a mailbox having the same local part as an alias

src/backend/mailbox_manager/tests/api/aliases/test_api_aliases_create.py

@@ -80,7 +80,7 @@ def test_api_aliases_create__duplicate_forbidden():
     assert models.Alias.objects.filter(domain=access.domain).count() == 1
 
 
-def test_api_aliases_create__existing_alias_bad_request():
+def test_api_aliases_create__existing_mailbox_bad_request():
     """Cannot create alias if local_part is already used by a mailbox."""
     access = factories.MailDomainAccessFactory(
         role="owner", domain=factories.MailDomainEnabledFactory()
@@ -95,7 +95,7 @@ def test_api_aliases_create__existing_alias_bad_request():
     )
     assert response.status_code == status.HTTP_400_BAD_REQUEST
     assert response.json() == {
-        "local_part": [f'Local part "{mailbox.local_part}" already used for a mailbox.']
+        "local_part": [f'Local part "{mailbox.local_part}" already used by a mailbox.']
     }
     assert not models.Alias.objects.exists()
 

src/backend/mailbox_manager/tests/api/aliases/test_api_aliases_delete.py

@@ -3,7 +3,10 @@ Tests for aliases API endpoint in People's app mailbox_manager.
 Focus on "list" action.
 """
 
+import re
+
 import pytest
+import responses
 from rest_framework import status
 from rest_framework.test import APIClient
 
@@ -87,6 +90,7 @@ def test_api_aliases_delete__viewer_can_delete_self_alias():
     assert not models.Alias.objects.exists()
 
 
+@responses.activate
 def test_api_aliases_delete__administrators_allowed():
     """
     Administrators of a mail domain should be allowed to delete accesses excepted owner accesses.
@@ -97,6 +101,14 @@ def test_api_aliases_delete__administrators_allowed():
     )
     alias = factories.AliasFactory(domain=mail_domain)
 
+    # Mock dimail response
+    responses.add(
+        responses.POST,
+        re.compile(r".*/aliases/"),
+        status=status.HTTP_204_NO_CONTENT,
+        content_type="application/json",
+    )
+
     client = APIClient()
     client.force_login(authenticated_user)
     response = client.delete(

src/backend/mailbox_manager/tests/api/mailboxes/test_api_mailboxes_create.py

@@ -1,7 +1,7 @@
 """
 Unit tests for the mailbox API
 """
-# pylint: disable=W0613
+# pylint: disable=W0613, C0302
 
 import json
 import re
@@ -436,6 +436,35 @@ def test_api_mailboxes__create_pending_mailboxes(domain_status, mailbox_data):
     assert mailbox.status == "pending"
 
 
+def test_api_mailboxes__existing_alias_bad_request(mailbox_data):
+    """
+    Cannot create mailbox if local_part is already used by an alias.
+    """
+    alias = factories.AliasFactory()
+    access = factories.MailDomainAccessFactory(
+        role=enums.MailDomainRoleChoices.ADMIN, domain=alias.domain
+    )
+
+    client = APIClient()
+    client.force_login(access.user)
+    # No response because we expect no outside calls to be made
+    response = client.post(
+        f"/api/v1.0/mail-domains/{access.domain.slug}/mailboxes/",
+        {
+            "local_part": alias.local_part,
+            "first_name": mailbox_data["first_name"],
+            "last_name": mailbox_data["last_name"],
+            "secondary_email": mailbox_data["secondary_email"],
+        },
+        format="json",
+    )
+    assert response.status_code == status.HTTP_400_BAD_REQUEST
+    assert response.json() == {
+        "local_part": [f'Local part "{alias.local_part}" already used by an alias.']
+    }
+    assert not models.Mailbox.objects.exists()
+
+
 ### REACTING TO DIMAIL-API
 ### We mock dimail's responses to avoid testing dimail's container too
 @responses.activate