Add an explaining message to the should-not-get-there assertion

diff --git a/lib/sqlalchemy/dialects/postgresql/ranges.py b/lib/sqlalchemy/dialects/postgresql/ranges.py
index f5bb72da34e1acacf1bb2f1584ad96569ff74305..a4c39d0639f6282acf3d120678b5ab5d1c87d345 100644 (file)
--- a/lib/sqlalchemy/dialects/postgresql/ranges.py
+++ b/lib/sqlalchemy/dialects/postgresql/ranges.py
@@ -561,8 +561,7 @@ class Range(Generic[_T]):
             else:
                 return Range(oupper, supper, bounds=rlower_b + supper_b)
 
-        # TODO: figure out if I handled all the cases above
-        assert False
+        assert False, f"Unhandled case computing {self} - {other}"
 
     __sub__ = difference