From 64857150bf818f6d6a7296749481dfa83c325762 Mon Sep 17 00:00:00 2001
From: Andrea Papaluca <andreapapaluca@gmail.com>
Date: Mon, 26 Feb 2024 16:20:16 +0400
Subject: [PATCH] cov: adding coverage to some defined gates errors

---
 src/qibo/_openqasm.py             | 10 ++++++++++
 tests/test_models_circuit_qasm.py | 13 ++++++++++++-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/qibo/_openqasm.py b/src/qibo/_openqasm.py
index 2eb6a7bcff..e152914c1b 100644
--- a/src/qibo/_openqasm.py
+++ b/src/qibo/_openqasm.py
@@ -42,6 +42,16 @@ def get_gate(self, qubits: Union[list, tuple], args: Union[list, tuple]):
         Returns:
             :class:`qibo.gates.special.FusedGate`: the composed gate evaluated on the input qubits with the input arguments.
         """
+        if len(self.args) != len(args):
+            raise_error(
+                ValueError,
+                f"Invalid `args` argument passed to the user-defined gate `{self.name}` upon construction. {args} was passed but something of the form {self.args} is expected.",
+            )
+        elif len(self.qubits) != len(qubits):
+            raise_error(
+                ValueError,
+                f"Invalid `qubits` argument passed to the user-defined gate `{self.name}` upon construction. {qubits} was passed but something of the form {self.qubits} is expected.",
+            )
         qubit_map = dict(zip(self.qubits, qubits))
         args_map = dict(zip(self.args, args))
         return self._construct_fused_gate(self.gates, qubits, qubit_map, args_map)
diff --git a/tests/test_models_circuit_qasm.py b/tests/test_models_circuit_qasm.py
index 867aec5a8e..5170b3bd01 100644
--- a/tests/test_models_circuit_qasm.py
+++ b/tests/test_models_circuit_qasm.py
@@ -487,6 +487,18 @@ def test_from_qasm_invalid_parametrized_gates():
     with pytest.raises(parser.QASM3ParsingError):
         c = Circuit.from_qasm(target)
 
+    target = """OPENQASM 2.0;
+include "qelib1.inc";
+qreg q[3];
+gate bob(theta,alpha) q0,q1 { h q1; cx q0,q1; rz(theta) q1; rx(alpha) q0; h q1; }
+"""
+
+    with pytest.raises(ValueError):
+        c = Circuit.from_qasm(f"{target}bob(0.1, 0.2, 0.3) q[1],q[0];")
+
+    with pytest.raises(ValueError):
+        c = Circuit.from_qasm(f"{target}bob(0.1, 0.2) q[1],q[0],q[2];")
+
 
 def test_from_qasm_gate_command(backend):
     target = """OPENQASM 2.0;
@@ -497,7 +509,6 @@ def test_from_qasm_gate_command(backend):
 bob(-pi/2,pi) q[0],q[2];
 alice q[1],q[0];"""
     c = Circuit.from_qasm(target)
-    print(c.draw())
 
     def bob(theta, alpha, q0, q1):
         gate = gates.FusedGate(q0, q1)