raise error when parsing dict with duplicate keys

Author: jdidion

fgpyo/util/inspect.py

@@ -217,7 +217,10 @@ def dict_parse(dict_string: str) -> Dict[Any, Any]:
                     len(inner_splits) % 2 == 0
                 ), "Inner splits of dict didn't have matched key val pairs"
                 for i in range(0, len(inner_splits), 2):
-                    out_dict[key_parser(inner_splits[i])] = val_parser(inner_splits[i + 1])
+                    key = key_parser(inner_splits[i])
+                    if key in out_dict:
+                        raise ValueError("Duplicate key found in dict: {}".format(key))
+                    out_dict[key] = val_parser(inner_splits[i + 1])
             return out_dict
 
     return functools.partial(dict_parse)

fgpyo/util/tests/test_inspect.py

@@ -10,10 +10,10 @@
 from fgpyo.util.inspect import attr_from
 from fgpyo.util.inspect import attribute_has_default
 from fgpyo.util.inspect import attribute_is_optional
+from fgpyo.util.inspect import dict_parser
 from fgpyo.util.inspect import list_parser
 from fgpyo.util.inspect import set_parser
 from fgpyo.util.inspect import tuple_parser
-from fgpyo.util.inspect import dict_parser
 
 
 @attr.s(auto_attribs=True, frozen=True)
@@ -86,6 +86,7 @@ def test_set_parser() -> None:
     parser = set_parser(Foo, Set[int], {})
     assert parser("{}") == set()
     assert parser("{1,2,3}") == {1, 2, 3}
+    assert parser("{1,1,2,3}") == {1, 2, 3}
 
 
 def test_tuple_parser() -> None:
@@ -98,3 +99,9 @@ def test_dict_parser() -> None:
     parser = dict_parser(Foo, Dict[int, str], {})
     assert parser("{}") == {}
     assert parser("{123;a}") == {123: "a"}
+
+
+def test_dict_parser_with_duplicate_keys() -> None:
+    parser = dict_parser(Foo, Dict[int, str], {})
+    with pytest.raises(ValueError):
+        parser("{123;a,123;b}")