[testing] Fix for IQM mock server when generating sample results (#2604)

Signed-off-by: Pradnya Khalate <pkhalate@nvidia.com>
Co-authored-by: Ben Howe <bhowe@nvidia.com>

Author: khalatepradnya

python/tests/backends/test_IQM.py

@@ -65,6 +65,7 @@ def startUpMockServer():
         pytest.exit("Mock server did not start in time, skipping tests.",
                     returncode=1)
 
+    cudaq.set_random_seed(13)
     # Set the targeted QPU
     os.environ["IQM_TOKENS_FILE"] = tmp_tokens_file.name
     kwargs = {"qpu-architecture": "Apollo"}
@@ -227,8 +228,7 @@ def basic_x():
         custom_x(qubit)
 
     counts = cudaq.sample(basic_x)
-    counts.dump()
-    # Gives result like { 1:999 0:0 }
+    # Gives result like { 0:0 1:1000 }
     assert counts['0'] == 0
 
     @cudaq.kernel
@@ -237,8 +237,8 @@ def basic_h():
         custom_h(qubit)
 
     counts = cudaq.sample(basic_h)
-    counts.dump()
-    assert "0" in counts and "1" in counts
+    # Gives result like { 0:500 1:500 }
+    assert counts['0'] > 0 and counts['1'] > 0
 
     @cudaq.kernel
     def bell():
@@ -247,7 +247,7 @@ def bell():
         custom_x.ctrl(qubits[0], qubits[1])
 
     counts = cudaq.sample(bell)
-    # Gives result like { 11:499 10:0 01:0 00:499 }
+    # Gives result like { 00:500 01:0 10:0 11:500 }
     assert counts['01'] == 0 and counts['10'] == 0
 
 
@@ -264,7 +264,7 @@ def bell_pair():
         custom_cnot(qubits[0], qubits[1])
 
     counts = cudaq.sample(bell_pair)
-    # Gives result like { 11:499 10:0 01:0 00:499 }
+    # Gives result like { 00:500 01:0 10:0 11:500 }
     assert counts['01'] == 0 and counts['10'] == 0
 
     cudaq.register_operation(
@@ -281,7 +281,7 @@ def ctrl_z_kernel():
         x(controls)
 
     counts = cudaq.sample(ctrl_z_kernel)
-    assert counts["0010011"] == 999
+    assert counts["0010011"] == 1000
 
 
 # leave for gdb debugging

utils/mock_qpu/iqm/__init__.py

@@ -237,7 +237,7 @@ def _simulate_circuit(instructions: list[iqm_client.Instruction],
                                    measurement_qubits_positions)
     probabilities = np.diag(partial_trace)
     return {
-        ms: int(prob * shots) for ms, prob in zip(
+        ms: int(round(prob * shots)) for ms, prob in zip(
             _generate_measurement_strings(len(measurement_qubits_positions)),
             probabilities,
         )