handoff fixes

backend/tests/test_external_reply_service.py

@@ -0,0 +1,57 @@
+from bson import ObjectId
+
+from app.services.external_reply_service import build_external_reply_plan
+from app.services.thread_service import threading_fields_from_parent
+
+
+def test_build_external_reply_references_gmail_parent():
+    parent = {
+        "_id": ObjectId(),
+        "internet_message_id": "<gmail-a@mail.gmail.com>",
+        "message_id": "<gmail-a@mail.gmail.com>",
+        "references": [],
+        "subject": "lets try one more time",
+    }
+    plan = build_external_reply_plan(
+        parent_external_message=parent,
+        body_text="I hear you.",
+        recipients=["customer@gmail.com"],
+    )
+    assert plan.threading.in_reply_to == "<gmail-a@mail.gmail.com>"
+    assert plan.threading.references == ["<gmail-a@mail.gmail.com>"]
+    assert plan.subject == "Re: lets try one more time"
+    assert plan.threading.replying_to_internet_message_id == "<gmail-a@mail.gmail.com>"
+
+
+def test_build_external_reply_chains_references_for_multi_round():
+    parent = {
+        "_id": ObjectId(),
+        "internet_message_id": "<a2@gmail.com>",
+        "message_id": "<a2@gmail.com>",
+        "references": ["<a1@gmail.com>", "<g1@gentic.email>"],
+        "subject": "Re: lets try one more time",
+    }
+    threading = threading_fields_from_parent(parent)
+    assert threading["in_reply_to"] == "<a2@gmail.com>"
+    assert threading["references"] == [
+        "<a1@gmail.com>",
+        "<g1@gentic.email>",
+        "<a2@gmail.com>",
+    ]
+
+
+def test_external_reply_never_uses_internal_object_id_as_in_reply_to():
+    parent = {
+        "_id": ObjectId(),
+        "internet_message_id": "<gmail-a@mail.gmail.com>",
+        "message_id": "<gmail-a@mail.gmail.com>",
+        "references": [],
+        "subject": "hello",
+    }
+    plan = build_external_reply_plan(
+        parent_external_message=parent,
+        body_text="reply",
+        recipients=["customer@gmail.com"],
+    )
+    assert str(parent["_id"]) not in (plan.threading.in_reply_to or "")
+    assert all(str(parent["_id"]) not in ref for ref in plan.threading.references)