Add unit tests for exception handling

.gitignore

@@ -53,7 +53,6 @@ logs/
 # Dev-only folders
 frontend/
 scripts/
-tests/
 benchmarks/
 LongMemEval/
 backboard/

tests/test_exception.py

@@ -0,0 +1,149 @@
+import pytest
+
+from src.utils.exceptions import (
+    XMemError,
+    ConfigurationError,
+    ValidationError,
+    VectorStoreError,
+    VectorStoreConnectionError,
+    VectorStoreValidationError,
+    VectorNotFoundError,
+    DatabaseError,
+    DatabaseConnectionError,
+    LLMError,
+    LLMRateLimitError,
+    LLMContextLengthError,
+    EmbeddingError,
+)
+
+
+class TestXMemError:
+
+    def test_str_includes_operation_when_provided(self):
+        err = XMemError("something broke", operation="save")
+        assert str(err) == "[save] something broke"
+
+    def test_str_returns_message_only_when_no_operation(self):
+        err = XMemError("something broke")
+        assert str(err) == "something broke"
+
+    def test_mssg_attribute_is_accessible(self):
+        err = XMemError("hello")
+        assert str(err) == "hello"
+
+    def test_operation_is_none_by_default(self):
+        err = XMemError("message")
+        assert err.operation == None
+
+    def test_operation_attribute_is_accessible(self):
+        err = XMemError("msg", operation="delete")
+        assert err.operation == "delete"
+
+    def test_details_defaults_to_empty_dict_when_not_provided(self):
+        err = XMemError("msg")
+        assert err.details == {}
+
+    def test_details_defaults_to_empty_dict_when_none_passed(self):
+        err = XMemError("msg", details=None)
+        assert err.details == {}
+
+    def test_details_stores_provided_dict(self):
+        err = XMemError("msg", details={"user_id": "123", "count": 5})
+        assert err.details["user_id"] == "123"
+        assert err.details["count"] == 5
+
+    def test_repr_contains_class_name(self):
+        err = XMemError("msg", operation="op")
+        assert "XMemError" in repr(err)
+
+    def test_repr_contains_message_and_operation(self):
+        err = XMemError("msg", operation="op")
+        assert "msg" in repr(err)
+        assert "op" in repr(err)
+
+
+class TestToDict:
+
+    def test_to_dict_has_required_keys(self):
+        err = XMemError("msg")
+        result = err.to_dict()
+        assert "error" in result
+        assert "message" in result
+        assert "operation" in result
+        assert "details" in result
+
+    def test_to_dict_error_key_is_class_name(self):
+        err = XMemError("msg")
+        assert err.to_dict()["error"] == "XMemError"
+
+    def test_to_dict_subclass_uses_subclass_name(self):
+        err = ValidationError("bad input")
+        assert err.to_dict()["error"] == "ValidationError"
+
+    def test_to_dict_message_matches(self):
+        err = XMemError("something went wrong", operation="fetch")
+        assert err.to_dict()["message"] == "something went wrong"
+
+    def test_to_dict_operation_matches(self):
+        err = XMemError("msg", operation="fetch")
+        assert err.to_dict()["operation"] == "fetch"
+
+    def test_to_dict_details_matches(self):
+        err = XMemError("msg", details={"key": "value"})
+        assert err.to_dict()["details"] == {"key": "value"}
+
+
+class TestExceptionHierarchy:
+
+    def test_configuration_error_is_caught_as_xmem_error(self):
+        with pytest.raises(XMemError):
+            raise ConfigurationError("missing key")
+
+    def test_validation_error_is_caught_as_xmem_error(self):
+        with pytest.raises(XMemError):
+            raise ValidationError("bad input")
+
+    def test_vector_store_error_is_caught_as_xmem_error(self):
+        with pytest.raises(XMemError):
+            raise VectorStoreError("store failed")
+
+    def test_vector_store_connection_error_is_caught_as_vector_store_error(
+            self):
+        with pytest.raises(VectorStoreError):
+            raise VectorStoreConnectionError("cannot connect")
+
+    def test_vector_store_connection_error_is_caught_as_xmem_error(self):
+        with pytest.raises(XMemError):
+            raise VectorStoreConnectionError("cannot connect")
+
+    def test_vector_not_found_error_is_caught_as_vector_store_error(self):
+        with pytest.raises(VectorStoreError):
+            raise VectorNotFoundError("id not found")
+
+    def test_database_error_is_caught_as_xmem_error(self):
+        with pytest.raises(XMemError):
+            raise DatabaseError("db failed")
+
+    def test_database_connection_error_is_caught_as_database_error(self):
+        with pytest.raises(DatabaseError):
+            raise DatabaseConnectionError("cannot connect to mongo")
+
+    def test_llm_error_is_caught_as_xmem_error(self):
+        with pytest.raises(XMemError):
+            raise LLMError("llm failed")
+
+    def test_llm_rate_limit_error_is_caught_as_llm_error(self):
+        with pytest.raises(LLMError):
+            raise LLMRateLimitError("rate limited")
+
+    def test_llm_context_length_error_is_caught_as_llm_error(self):
+        with pytest.raises(LLMError):
+            raise LLMContextLengthError("too long")
+
+    def test_embedding_error_is_caught_as_xmem_error(self):
+        with pytest.raises(XMemError):
+            raise EmbeddingError("embed failed")
+
+    def test_validation_error_is_not_a_vector_store_error(self):
+        err = ValidationError("bad input")
+        assert not isinstance(err, VectorStoreError)