Fix query indexing at the cache boundary

aredis_om/model/model.py

@@ -2059,7 +2059,7 @@ def __getitem__(self, item: int):
                 "Cannot use [] notation with async code. "
                 "Use FindQuery.get_item() instead."
             )
-        if self._model_cache and len(self._model_cache) >= item:
+        if self._model_cache and len(self._model_cache) > item:
             return self._model_cache[item]
 
         query = self.copy(offset=item, limit=1)
@@ -2083,7 +2083,7 @@ async def get_item(self, item: int):
         NOTE: This method is included specifically for async users, who
         cannot use the notation Model.find()[1000].
         """
-        if self._model_cache and len(self._model_cache) >= item:
+        if self._model_cache and len(self._model_cache) > item:
             return self._model_cache[item]
 
         query = self.copy(offset=item, limit=1)

tests/test_find_query_cache.py

@@ -0,0 +1,65 @@
+from unittest import mock
+
+import pytest
+
+from aredis_om import FindQuery, HashModel
+from aredis_om.model import model as model_module
+from aredis_om.util import ASYNC_MODE
+
+from .conftest import py_test_mark_asyncio
+
+
+@pytest.fixture
+def query(monkeypatch):
+    fake_db = mock.AsyncMock()
+
+    async def search(*args):
+        offset = args[4]
+        if offset >= 2:
+            return [2]
+        return [2, f"doc:{offset}", ["pk", str(offset), "name", str(offset)]]
+
+    fake_db.execute_command.side_effect = search
+    monkeypatch.setattr(model_module, "has_redisearch", lambda conn: True)
+
+    class Item(HashModel, index=True):
+        name: str
+
+        class Meta:
+            database = fake_db
+
+    return FindQuery(expressions=[], model=Item, limit=1)
+
+
+@pytest.mark.parametrize("item", [-1, 0, 1, 2])
+@py_test_mark_asyncio
+async def test_get_item_with_partial_cache(query, item):
+    cached = await query.execute(exhaust_results=False)
+    assert [model.name for model in cached] == ["0"]
+
+    if item == 2:
+        with pytest.raises(IndexError):
+            await query.get_item(item)
+    else:
+        result = await query.get_item(item)
+        assert result.name == ("0" if item <= 0 else "1")
+        if item <= 0:
+            assert result is cached[0]
+            assert query.model.db().execute_command.call_count == 1
+
+
+@pytest.mark.skipif(ASYNC_MODE, reason="[] notation requires sync queries")
+@pytest.mark.parametrize("item", [-1, 0, 1, 2])
+def test_getitem_with_partial_cache(query, item):
+    cached = query.execute(exhaust_results=False)
+    assert [model.name for model in cached] == ["0"]
+
+    if item == 2:
+        with pytest.raises(IndexError):
+            query[item]
+    else:
+        result = query[item]
+        assert result.name == ("0" if item <= 0 else "1")
+        if item <= 0:
+            assert result is cached[0]
+            assert query.model.db().execute_command.call_count == 1