Fix circuit metadata serialization bug (#648)

* Fix serialization bug

* Revert "Fix serialization bug"

This reverts commit 72a08bc.

* Fix serialization bug

* add reno

* add unit test

qiskit_ibm_provider/utils/json.py

@@ -212,7 +212,9 @@ def default(self, obj: Any) -> Any:  # pylint: disable=arguments-differ
         if isinstance(obj, QuantumCircuit):
             value = _serialize_and_encode(
                 data=obj,
-                serializer=lambda buff, data: dump(data, buff),  # type: ignore[no-untyped-call]
+                serializer=lambda buff, data: dump(
+                    data, buff, RuntimeEncoder
+                ),  # type: ignore[no-untyped-call]
             )
             return {"__type__": "QuantumCircuit", "__value__": value}
         if isinstance(obj, Parameter):

releasenotes/notes/fix-serialization-bug-adabc48b48cc1ccd.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Fixed an issue where circuit metadata was not being serialized correctly 
+    resulting in a type error.
+

test/unit/test_serialization.py

@@ -13,20 +13,21 @@
 """Test serializing and deserializing data sent to the server."""
 
 import json
-
+import numpy as np
 from qiskit import assemble
 from qiskit import QuantumCircuit, QuantumRegister, ClassicalRegister
 from qiskit.circuit import Parameter
 
 from qiskit_ibm_provider.utils.json_encoder import IBMJsonEncoder
+from qiskit_ibm_provider.utils.json import RuntimeEncoder
 from ..ibm_test_case import IBMTestCase
 
 
 class TestSerialization(IBMTestCase):
     """Test data serialization."""
 
     def test_exception_message(self):
-        """Test executing job with Parameter in methadata."""
+        """Test executing job with Parameter in metadata."""
         quantum_register = QuantumRegister(1)
         classical_register = ClassicalRegister(1)
         my_circ_str = "test_metadata"
@@ -65,3 +66,12 @@ def test_encode_replace(self):
             '{"t1": 1, "null": null, "a": 0.2, "list": [1, 2, {"ld": 1, "2": 3, "alfa": 0.1}]}',
             IBMJsonEncoder().encode(test_dir),
         )
+
+    def test_circuit_metadata(self):
+        """Test serializing circuit metadata."""
+
+        circ = QuantumCircuit(1)
+        circ.metadata = {"test": np.arange(0, 10)}
+        payload = {"circuits": [circ]}
+
+        self.assertTrue(json.dumps(payload, cls=RuntimeEncoder))