Preserve sub-component hierarchy in export/import

tests/test_acceptance.py

@@ -844,6 +844,76 @@ def test_full_roundtrip_export_import(client):
     assert b"Import Results" in resp.data
 
 
+def test_export_json_includes_parent_fields(client):
+    _setup_rc_car(client)
+    data = _json.loads(client.get("/export/all.json").data)
+    devs = {d["name"]: d for d in data["devices"]}
+    assert devs["RC Car Set"]["parent_id"] is None
+    assert devs["Remote"]["parent_id"] == devs["RC Car Set"]["id"]
+    assert devs["Remote"]["parent_name"] == "RC Car Set"
+
+
+def test_import_rebuilds_hierarchy(client):
+    payload = _make_import_payload(devices=[
+        _dev(10, "Hub", battery_slots=0, battery_size=None),
+        _dev(11, "Probe", parent_id=10),
+    ])
+    resp = _post_import(client, payload)
+    assert resp.status_code == 200
+    data = _json.loads(client.get("/export/all.json").data)
+    devs = {d["name"]: d for d in data["devices"]}
+    assert devs["Probe"]["parent_id"] == devs["Hub"]["id"]
+    assert devs["Probe"]["parent_name"] == "Hub"
+    # parent's 0 slots survive the import (previously coerced to 1)
+    assert devs["Hub"]["battery_slots"] == 0
+
+
+def test_import_child_listed_before_parent(client):
+    payload = _make_import_payload(devices=[
+        _dev(11, "Probe", parent_id=10),
+        _dev(10, "Hub", battery_slots=0, battery_size=None),
+    ])
+    resp = _post_import(client, payload)
+    assert resp.status_code == 200
+    data = _json.loads(client.get("/export/all.json").data)
+    devs = {d["name"]: d for d in data["devices"]}
+    assert devs["Probe"]["parent_id"] == devs["Hub"]["id"]
+
+
+def test_import_subcomponent_missing_parent_becomes_top_level(client):
+    payload = _make_import_payload(devices=[_dev(11, "Probe", parent_id=99)])
+    resp = _post_import(client, payload)
+    assert resp.status_code == 200
+    data = _json.loads(client.get("/export/all.json").data)
+    devs = {d["name"]: d for d in data["devices"]}
+    assert devs["Probe"]["parent_id"] is None
+
+
+def test_import_empty_battery_size_stored_as_null(client):
+    payload = _make_import_payload(devices=[_dev(10, "NoSize", battery_size="")])
+    resp = _post_import(client, payload)
+    assert resp.status_code == 200
+    data = _json.loads(client.get("/export/all.json").data)
+    devs = {d["name"]: d for d in data["devices"]}
+    assert devs["NoSize"]["battery_size"] is None
+
+
+def test_roundtrip_import_preserves_hierarchy(client):
+    _setup_rc_car(client)
+    data = _json.loads(client.get("/export/all.json").data)
+    # rename everything so the import creates rows instead of skipping
+    for d in data["devices"]:
+        d["name"] = d["name"] + " v2"
+    buf = io.BytesIO(_json.dumps(data).encode())
+    resp = client.post("/import", data={"file": (buf, "export.json")},
+                       content_type="multipart/form-data")
+    assert resp.status_code == 200
+    data2 = _json.loads(client.get("/export/all.json").data)
+    devs = {d["name"]: d for d in data2["devices"]}
+    assert devs["Remote v2"]["parent_id"] == devs["RC Car Set v2"]["id"]
+    assert devs["Car v2"]["parent_id"] == devs["RC Car Set v2"]["id"]
+
+
 def test_device_detail_unassign_all(seeded_client):
     client = seeded_client
     # install battery 1 into device 1 (2-slot AA device)