Updates to test file and library file to keep module and testing

functions separate. The Config file needs to be reviewed to either change it to json or other
formats.

tests/test_qasm_quimb_backend.py

@@ -1,6 +1,27 @@
 import os
 
 import pytest
+import qibo
+from qibo.models import QFT
+import numpy as np
+import copy
+from timeit import default_timer as timer
+
+import config
+
+
+def init_state_sv(nqubits):
+    init_state = np.random.random(2**nqubits) + 1j * np.random.random(2**nqubits)
+    init_state = init_state / np.sqrt((np.abs(init_state) ** 2).sum())
+    # An unmodified init_state has to be converted to tn format
+    init_state_for_tn = copy.deepcopy(init_state)
+    return init_state, init_state_for_tn
+
+
+def qibo_qft(nqubits, init_state, swaps):
+    circ_qibo = QFT(nqubits, swaps)
+    state_vec = np.array(circ_qibo(init_state))
+    return circ_qibo, state_vec
 
 
 @pytest.mark.parametrize("nqubits", [1, 2, 5, 10])
@@ -8,4 +29,27 @@ def test_eval(nqubits: int):
     os.environ["QUIMB_NUM_PROCS"] = str(os.cpu_count())
     from qibotn import qasm_quimb
 
-    result = qasm_quimb.eval_QI_qft(nqubits)
+    init_state_qibo, init_state_for_tn = init_state_sv(nqubits=nqubits)
+
+    # Test qibo
+    qibo.set_backend(backend=config.qibo['backend'], \
+        platform=config.qibo['platform'])
+    start_time = timer()
+    qibo_circ, result_sv = qibo_qft(nqubits, init_state=init_state_qibo, \
+        swaps=config.qibo['swaps'])
+    end_time = timer()
+    qibo_time = end_time - start_time
+
+    # Convert to qasm for other backends
+    qasm_circ = qibo_circ.to_qasm()
+
+    # Test quimb
+    start_time = timer()
+    result_tn = qasm_quimb.eval_QI_qft(nqubits=nqubits, qasm_circ=qasm_circ, \
+        init_state=init_state_for_tn, backend=config.quimb['backend'], \
+            swaps=config.quimb['swaps'])
+    end_time = timer()
+    quimb_time = end_time - start_time
+
+    assert np.allclose(result_sv, result_tn), \
+        "Resulting dense vectors do not match"