Add test for 6350 (Qiskit#6369)

* Add test for 6350

* Move import

test/python/transpiler/test_basis_translator.py

@@ -26,6 +26,7 @@
 from qiskit.quantum_info import Operator
 from qiskit.transpiler.exceptions import TranspilerError
 from qiskit.transpiler.passes.basis import BasisTranslator, UnrollCustomDefinitions
+from qiskit.test.mock import FakeAthens
 
 
 from qiskit.circuit.library.standard_gates.equivalence_library import (
@@ -816,3 +817,41 @@ def test_condition_set_substitute_node(self):
         expected.measure(1, 1)
         expected.u2(0, pi, 0).c_if(cr, 1)
         self.assertEqual(circ_transpiled, expected)
+
+    def test_skip_target_basis_equivalences_1(self):
+        """Test that BasisTranslator skips gates in the target_basis - #6085"""
+
+        qstr = 'OPENQASM 2.0; \
+        include "qelib1.inc"; \
+        qreg q[5]; \
+        cu1(4.1564508) q[2],q[3]; \
+        ccx q[0],q[1],q[4]; \
+        rzz(0.48622471) q[0],q[2]; \
+        ccx q[3],q[4],q[1]; \
+        ch q[2],q[0]; \
+        y q[3]; \
+        cu3(2.5787688,1.3265772,3.1398664) q[1],q[4]; \
+        id q[0]; \
+        y q[1]; \
+        t q[2]; \
+        t q[3]; \
+        tdg q[4]; \
+        cz q[0],q[1]; \
+        ccx q[2],q[4],q[3]; \
+        rx(5.976651) q[1]; \
+        u3(4.8520889,3.6025647,5.7475542) q[2]; \
+        cswap q[0],q[3],q[4]; \
+        rz(2.1885681) q[2]; \
+        cu3(2.7675189,4.5725211,2.9940136) q[0],q[3]; \
+        cx q[1],q[4];'
+        circ = QuantumCircuit()
+        circ = circ.from_qasm_str(qstr)
+
+        circ_transpiled = transpile(
+            circ,
+            backend=FakeAthens(),
+            basis_gates=["id", "rz", "sx", "x", "cx"],
+            routing_method="sabre",
+            seed_transpiler=42,
+        )
+        self.assertEqual(circ_transpiled.count_ops(), {"cx": 91, "rz": 66, "sx": 22})