test(email): контактный адрес, Reply-To и тестовая отправка письма

Покрытие валидации/сохранения contact_email, простановки Reply-To в
письмах регистрации/приглашений/саммари при включённом и выключенном
контактном адресе, и эндпоинта тестовой отправки (успех, дефолтный
получатель, сбой транспорта без утечки логина/пароля).

backend/tests/test_invitations_task.py

@@ -19,6 +19,7 @@ from celery.exceptions import MaxRetriesExceededError
 from sqlalchemy import text
 
 from core.db import engine
+from core.plugins.config import ChatConfig, InstanceConfig, SummarizerConfig, TranscriberConfig
 from services.conference_ids import generate_number, generate_slug
 from services.email import EmailAttachment, EmailSendError
 from workers.tasks import invitations as invitations_module
@@ -65,10 +66,13 @@ class _FakeEmailBackend:
         body: str,
         html_body: str | None = None,
         attachments: tuple[EmailAttachment, ...] = (),
+        reply_to: str | None = None,
     ) -> None:
         if to in self._fail_for:
             raise EmailSendError(f"сбой отправки {to}", retryable=self._retryable)
-        self.sent.append({"to": to, "subject": subject, "attachments": attachments})
+        self.sent.append(
+            {"to": to, "subject": subject, "attachments": attachments, "reply_to": reply_to}
+        )
 
 
 class _Fixture:
@@ -364,6 +368,48 @@ async def test_pinned_conference_sends_to_owner_and_past_participants_with_email
     assert delivered == sent_to
 
 
+def _cfg(
+    *, contact_email_enabled: bool = False, contact_email: str | None = None
+) -> InstanceConfig:
+    return InstanceConfig(
+        transcriber=TranscriberConfig(),
+        summarizer=SummarizerConfig(),
+        chat=ChatConfig(),
+        contact_email_enabled=contact_email_enabled,
+        contact_email=contact_email,
+    )
+
+
+async def test_invitations_set_reply_to_when_contact_email_enabled(
+    fx: _Fixture, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    """Включённый контактный адрес инстанса — приглашение несёт `Reply-To`."""
+    mock_backend = _FakeEmailBackend()
+    monkeypatch.setattr(invitations_module, "create_email_backend", lambda settings: mock_backend)
+
+    await send_invitations_async(
+        _FakeTask(),
+        fx.conference_id,
+        plugins_config=_cfg(contact_email_enabled=True, contact_email="contact@vidconf.example"),
+    )
+
+    assert mock_backend.sent
+    assert all(call["reply_to"] == "contact@vidconf.example" for call in mock_backend.sent)
+
+
+async def test_invitations_no_reply_to_when_contact_email_disabled(
+    fx: _Fixture, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    """Контактный адрес выключен (дефолт) — `Reply-To` не проставляется."""
+    mock_backend = _FakeEmailBackend()
+    monkeypatch.setattr(invitations_module, "create_email_backend", lambda settings: mock_backend)
+
+    await send_invitations_async(_FakeTask(), fx.conference_id, plugins_config=_cfg())
+
+    assert mock_backend.sent
+    assert all(call["reply_to"] is None for call in mock_backend.sent)
+
+
 async def test_explicit_emails_override_default_recipients(
     fx: _Fixture, monkeypatch: pytest.MonkeyPatch
 ) -> None: