test: 补充知识处理、检索与 Agent 回归用例

覆盖切块、向量检索、工具调用和历史预算；模型相关用例使用桩。

backend/tests/agents/test_encrypted_storage.py

@@ -0,0 +1,88 @@
+"""
+Copyright 2024-2026 ReplyPier
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+The agno agent session store keeps its own copy of the transcript, so these tests
+guard the seam that keeps that copy encrypted.
+"""
+
+import pytest
+from agno.storage.session.agent import AgentSession
+
+from app.agents.encrypted_storage import EncryptedPostgresAgentStorage
+from app.core.encryption import CURRENT_KEY_ID, ENCRYPTED_PREFIX, JSON_MARKER, SEPARATOR
+
+MEMORY = {"runs": [{"content": "my card number is 4111 1111 1111 1111"}]}
+
+
+class FakeStorage(EncryptedPostgresAgentStorage):
+    """The subclass under test, with only the database swapped for a dict.
+
+    `rows` holds what Postgres would hold, so every assertion about ciphertext at
+    rest is an assertion about the real column value.
+    """
+
+    def __init__(self):
+        self.rows = {}
+
+
+@pytest.fixture
+def storage(monkeypatch):
+    """Patch agno's own read/upsert — the supers — so the subclass's overrides,
+    not a hand-written stand-in, are what the tests exercise."""
+    def fake_upsert(self, session, create_and_retry=True):
+        self.rows[session.session_id] = session.memory
+        return self.read(session_id=session.session_id)
+
+    def fake_read(self, session_id, user_id=None):
+        if session_id not in self.rows:
+            return None
+        return AgentSession(session_id=session_id, memory=self.rows[session_id])
+
+    monkeypatch.setattr("agno.storage.postgres.PostgresStorage.upsert", fake_upsert)
+    monkeypatch.setattr("agno.storage.postgres.PostgresStorage.read", fake_read)
+    return FakeStorage()
+
+
+def test_memory_is_encrypted_at_rest(storage):
+    session = AgentSession(session_id="s1", agent_id="a1", memory=dict(MEMORY))
+
+    returned = storage.upsert(session)
+
+    stored = storage.rows["s1"]
+    assert list(stored) == [JSON_MARKER]
+    assert "4111" not in str(stored)
+    assert stored[JSON_MARKER].startswith(
+        f"{ENCRYPTED_PREFIX}{SEPARATOR}{CURRENT_KEY_ID}{SEPARATOR}")
+    # The caller gets plaintext back, and the live object it still holds is untouched.
+    assert returned.memory == MEMORY
+    assert session.memory == MEMORY
+
+
+def test_legacy_plaintext_memory_still_loads(storage):
+    """Sessions agno wrote before this change hold a plain dict."""
+    storage.rows["legacy"] = dict(MEMORY)
+    assert storage.read("legacy").memory == MEMORY
+
+
+def test_undecryptable_memory_degrades_to_no_history(storage):
+    """A damaged blob must not stop the agent answering the customer."""
+    storage.rows["broken"] = {JSON_MARKER: f"{ENCRYPTED_PREFIX}{SEPARATOR}{CURRENT_KEY_ID}{SEPARATOR}x"}
+    assert storage.read("broken").memory is None
+
+
+def test_missing_memory_is_left_alone(storage):
+    storage.upsert(AgentSession(session_id="empty", memory=None))
+    assert storage.rows["empty"] is None
+    assert storage.read("empty").memory is None