Add unit tests for streaming emitters and registry wiring.

surfsense_backend/tests/unit/services/streaming/test_emitter.py

@@ -0,0 +1,79 @@
+"""Pin the wire compactness rule and the top-level ``emitted_by`` field name."""
+
+from __future__ import annotations
+
+import pytest
+
+from app.services.streaming.emitter import (
+    Emitter,
+    attach_emitted_by,
+    main_emitter,
+    subagent_emitter,
+)
+
+pytestmark = pytest.mark.unit
+
+
+def test_main_emitter_payload_contains_only_level() -> None:
+    payload = main_emitter().to_payload()
+    assert payload == {"level": "main"}
+
+
+def test_subagent_emitter_payload_includes_all_set_fields() -> None:
+    payload = subagent_emitter(
+        subagent_type="deliverables",
+        subagent_run_id="subagent_abc",
+        parent_tool_call_id="call_xyz",
+    ).to_payload()
+    assert payload == {
+        "level": "subagent",
+        "subagent_type": "deliverables",
+        "subagent_run_id": "subagent_abc",
+        "parent_tool_call_id": "call_xyz",
+    }
+
+
+def test_subagent_emitter_payload_omits_unset_optional_fields() -> None:
+    """parent_tool_call_id is None when the run is started outside a tool boundary."""
+    payload = Emitter(
+        level="subagent",
+        subagent_type="email",
+        subagent_run_id="subagent_1",
+    ).to_payload()
+    assert "parent_tool_call_id" not in payload
+    assert payload["subagent_type"] == "email"
+
+
+def test_extra_fields_merge_into_payload() -> None:
+    """Future extension fields (e.g. lane colour, label) flow through ``extra``."""
+    emitter = subagent_emitter(
+        subagent_type="search",
+        subagent_run_id="r1",
+        extra={"label": "Web Search"},
+    )
+    assert emitter.to_payload()["label"] == "Web Search"
+
+
+def test_attach_emitted_by_with_none_is_noop() -> None:
+    payload = {"type": "text-delta", "delta": "hi"}
+    result = attach_emitted_by(payload, None)
+    assert "emitted_by" not in result
+    assert result is payload
+
+
+def test_attach_emitted_by_adds_payload_under_snake_case_top_level_key() -> None:
+    payload = {"type": "text-delta", "delta": "hi"}
+    attach_emitted_by(
+        payload,
+        subagent_emitter(
+            subagent_type="x",
+            subagent_run_id="y",
+            parent_tool_call_id="z",
+        ),
+    )
+    assert payload["emitted_by"] == {
+        "level": "subagent",
+        "subagent_type": "x",
+        "subagent_run_id": "y",
+        "parent_tool_call_id": "z",
+    }