Exceptions: documents and introduce type hierarchy #52

Author: greenrobot

objectbox/__init__.py

@@ -19,7 +19,7 @@
 from objectbox.model.entity import Entity
 from objectbox.model.properties import Id, String, Index, Bool, Int8, Int16, Int32, Int64, Float32, Float64, Bytes, BoolVector, Int8Vector, Int16Vector, Int32Vector, Int64Vector, Float32Vector, Float64Vector, CharVector, BoolList, Int8List, Int16List, Int32List, Int64List, Float32List, Float64List, CharList, Date, DateNano, Flex, HnswIndex, VectorDistanceType, HnswFlags
 from objectbox.model.model import Model
-from objectbox.c import CoreException, NotFoundException, version_core, DebugFlags
+from objectbox.c import DbException, CoreException, NotFoundException, version_core, DebugFlags
 from objectbox.version import Version
 from objectbox.condition import PropertyQueryCondition
 from objectbox.query import Query

objectbox/c.py

@@ -246,7 +246,15 @@ class OBX_query(ctypes.Structure):
 C.obx_last_error_code.restype = obx_err
 
 
-class CoreException(Exception):
+class DbException(Exception):
+    """ Base class for database exceptions. """
+    pass
+
+
+# TODO rename?
+class CoreException(DbException):
+    """ A database exception having a ``code`` attribute for error details. """
+
     codes = {
         0: "SUCCESS",
         404: "NOT_FOUND",
@@ -287,8 +295,11 @@ def last():
         return CoreException(C.obx_last_error())
 
 
-class NotFoundException(Exception):
-    pass
+class NotFoundException(CoreException):
+    """ Raised when an object is not found. """
+
+    def __init__(self):
+        super().__init__(404)
 
 
 def check_obx_err(code: obx_err, func, args) -> obx_err:

tests/test_basics.py

@@ -12,6 +12,7 @@
 # limitations under the License.
 
 import objectbox
+from objectbox.c import NotFoundException, CoreException
 from tests.common import create_test_store
 
 
@@ -32,3 +33,10 @@ def test_version():
 def test_open():
     store = create_test_store()
     store.close()
+
+
+def test_not_found_exception():
+    try:
+        raise NotFoundException()
+    except CoreException as e:
+        assert e.code == 404