Change Map.delete(key): raise a KeyError if key is not in the map

2 files changed, 5 insertions, 6 deletions

diff --git a/immutables/_map.c b/immutables/_map.c
index 445b713..3ed0393 100644
--- a/immutables/_map.c
+++ b/immutables/_map.c
@@ -2355,8 +2355,8 @@ map_without(MapObject *o, PyObject *key)
         case W_EMPTY:
             return map_new();
         case W_NOT_FOUND:
-            Py_INCREF(o);
-            return o;
+            PyErr_SetObject(PyExc_KeyError, key);
+            return NULL;
         case W_NEWNODE: {
             assert(new_root != NULL);
 
diff --git a/immutables/map.py b/immutables/map.py
index ffed188..b6d55dc 100644
--- a/immutables/map.py
+++ b/immutables/map.py
@@ -126,7 +126,7 @@ class BitmapNode:
         if key == key_or_null:
             return val_or_node
 
-        raise KeyError
+        raise KeyError(key)
 
     def without(self, shift, hash, key):
         bit = map_bitpos(hash, shift)
@@ -240,7 +240,7 @@ class CollisionNode:
         for i in range(0, self.size, 2):
             if self.array[i] == key:
                 return self.array[i + 1]
-        raise KeyError
+        raise KeyError(key)
 
     def assoc(self, shift, hash, key, val, added_leaf):
         if hash == self.hash:
@@ -388,8 +388,7 @@ class Map:
         if res is W_EMPTY:
             return Map()
         elif res is W_NOT_FOUND:
-            # raise KeyError(key)
-            return self
+            raise KeyError(key)
         else:
             m = Map.__new__(Map)
             m.__count = self.__count - 1