Update serialization for non-basic types

qiskit_ibm_provider/utils/json.py

@@ -203,8 +203,9 @@ def default(self, obj: Any) -> Any:  # pylint: disable=arguments-differ
                 return {"__type__": "ndarray", "__value__": obj.tolist()}
             value = _serialize_and_encode(obj, np.save, allow_pickle=False)
             return {"__type__": "ndarray", "__value__": value}
-        if isinstance(obj, np.int64):
-            return {"__type__": "int", "__value__": int(obj)}
+        if isinstance(obj, np.number):
+            # Maybe we should encode the numpy data type here for better accuracy.
+            return {"__type__": type(obj.item()).__name__, "__value__": obj.item()}
         if isinstance(obj, set):
             return {"__type__": "set", "__value__": list(obj)}
         if isinstance(obj, Result):
@@ -294,7 +295,14 @@ def object_hook(self, obj: Any) -> Any:
             if obj_type == "set":
                 return set(obj_val)
             if obj_type == "QuantumCircuit":
-                return _decode_and_deserialize(obj_val, load)[0]
+                return _decode_and_deserialize(
+                    data=obj_val,
+                    deserializer=lambda buff: load(
+                        buff, metadata_deserializer=RuntimeDecoder
+                    ),
+                )[
+                    0
+                ]  # type: ignore[no-untyped-call]
             if obj_type == "Parameter":
                 return _decode_and_deserialize(obj_val, _read_parameter, False)
             if obj_type == "ParameterExpression":

releasenotes/notes/bug-fix-metadata-numpy-number-support-7613af6c44b99107.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Fixed an issue where circuit metadata was not being serialized correctly 
+    for numpy numbers. In addition, added `RuntimeDecoder` as metadata deserializer.

test/unit/test_serialization.py

@@ -14,6 +14,9 @@
 
 import json
 import numpy as np
+
+from ddt import data, ddt
+
 from qiskit import assemble
 from qiskit import QuantumCircuit, QuantumRegister, ClassicalRegister
 from qiskit.circuit import Parameter
@@ -23,6 +26,7 @@
 from ..ibm_test_case import IBMTestCase
 
 
+@ddt
 class TestSerialization(IBMTestCase):
     """Test data serialization."""
 
@@ -67,11 +71,20 @@ def test_encode_replace(self):
             IBMJsonEncoder().encode(test_dir),
         )
 
-    def test_circuit_metadata(self):
+    @data(
+        np.arange(0, 10, 1),
+        np.arange(0.0, 10.0, 1),
+        np.int32(1),
+        np.int64(2),
+        np.float64(3.1),
+        complex(1, 1),
+        np.complex64(complex(1, 3)),
+        "TEST",
+    )
+    def test_circuit_metadata(self, metadata_test):
         """Test serializing circuit metadata."""
-
         circ = QuantumCircuit(1)
-        circ.metadata = {"test": np.arange(0, 10)}
+        circ.metadata = {"test": metadata_test}
         payload = {"circuits": [circ]}
 
         self.assertTrue(json.dumps(payload, cls=RuntimeEncoder))