feat(statehub): add offline write buffer relay

tests/test_edge_relay.py

@@ -0,0 +1,117 @@
+import httpx
+import pytest
+from httpx import ASGITransport, AsyncClient
+
+from api.edge.outbox import OutboxStore
+from api.edge.relay import create_app, replay_pending
+
+
+class FailingAsyncClient:
+    def __init__(self, *args, **kwargs):
+        pass
+
+    async def __aenter__(self):
+        return self
+
+    async def __aexit__(self, *exc_info):
+        return False
+
+    async def request(self, *args, **kwargs):
+        raise httpx.ConnectError("upstream down")
+
+    async def get(self, *args, **kwargs):
+        raise httpx.ConnectError("upstream down")
+
+
+class ConflictAsyncClient:
+    def __init__(self, *args, **kwargs):
+        pass
+
+    async def __aenter__(self):
+        return self
+
+    async def __aexit__(self, *exc_info):
+        return False
+
+    async def request(self, method, path, **kwargs):
+        request = httpx.Request(method, f"http://upstream{path}")
+        return httpx.Response(409, json={"error": "conflict"}, request=request)
+
+
+class SuccessAsyncClient:
+    def __init__(self, *args, **kwargs):
+        pass
+
+    async def __aenter__(self):
+        return self
+
+    async def __aexit__(self, *exc_info):
+        return False
+
+    async def request(self, method, path, **kwargs):
+        request = httpx.Request(method, f"http://upstream{path}")
+        return httpx.Response(201, json={"id": "central-id", "path": path}, request=request)
+
+
+@pytest.mark.asyncio
+async def test_relay_queues_allowlisted_write_when_upstream_unreachable(tmp_path, monkeypatch):
+    from api.edge import relay
+
+    monkeypatch.setattr(relay.httpx, "AsyncClient", FailingAsyncClient)
+    outbox_path = tmp_path / "edge.sqlite3"
+    app = create_app(upstream_url="http://upstream", outbox_path=str(outbox_path))
+
+    async with AsyncClient(transport=ASGITransport(app=app), base_url="http://edge") as client:
+        response = await client.post("/progress/", json={"event_type": "note", "summary": "queued"})
+
+    assert response.status_code == 202
+    body = response.json()
+    assert body["queued"] is True
+    assert body["route_class"] == "append"
+
+    store = OutboxStore(outbox_path)
+    queued = store.list(status="queued")
+    assert len(queued) == 1
+    assert queued[0].path == "/progress/"
+
+
+@pytest.mark.asyncio
+async def test_relay_replay_acks_successful_envelope(tmp_path, monkeypatch):
+    from api.edge import relay
+
+    monkeypatch.setattr(relay.httpx, "AsyncClient", SuccessAsyncClient)
+    store = OutboxStore(tmp_path / "edge.sqlite3")
+    envelope = store.enqueue(method="POST", path="/progress/", body={"event_type": "note", "summary": "queued"})
+
+    result = await replay_pending(store, upstream_url="http://upstream")
+
+    assert result["acked"] == 1
+    assert store.get(envelope.id).status == "acked"
+
+
+@pytest.mark.asyncio
+async def test_relay_rejects_online_only_write_when_upstream_unreachable(tmp_path, monkeypatch):
+    from api.edge import relay
+
+    monkeypatch.setattr(relay.httpx, "AsyncClient", FailingAsyncClient)
+    app = create_app(upstream_url="http://upstream", outbox_path=str(tmp_path / "edge.sqlite3"))
+
+    async with AsyncClient(transport=ASGITransport(app=app), base_url="http://edge") as client:
+        response = await client.delete("/tasks/abc")
+
+    assert response.status_code == 503
+    assert "not queueable" in response.json()["error"]
+
+
+@pytest.mark.asyncio
+async def test_relay_replay_marks_conflict(tmp_path, monkeypatch):
+    from api.edge import relay
+
+    monkeypatch.setattr(relay.httpx, "AsyncClient", ConflictAsyncClient)
+    store = OutboxStore(tmp_path / "edge.sqlite3")
+    envelope = store.enqueue(method="PATCH", path="/tasks/task-1", body={"status": "done"})
+
+    result = await replay_pending(store, upstream_url="http://upstream")
+
+    assert result["conflict"] == 1
+    assert store.get(envelope.id).status == "conflict"