test: Improve testing and resolve comments

CQCL · Sep 4, 2024 · 8fe14e2 · 8fe14e2
1 parent 04d83f5
commit 8fe14e2
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Showing 3 changed files with 13 additions and 2 deletions.
diff --git a/pytket/tests/passes_serialisation_test.py b/pytket/tests/passes_serialisation_test.py
@@ -299,6 +299,7 @@ def nonparam_predicate_dict(name: str) -> Dict[str, Any]:
     "AutoRebase": standard_pass_dict(
         {"name": "AutoRebase", "basis_allowed": ["H", "TK1", "CX"], "allow_swaps": True}
     ),
+    # ZZPhase must be a float and note a function.
     "DecomposeTK2": standard_pass_dict(
         {
             "name": "DecomposeTK2",

diff --git a/pytket/tests/transform_test.py b/pytket/tests/transform_test.py
@@ -209,6 +209,16 @@ def test_DecomposeTK2() -> None:
     assert c.n_gates_of_type(OpType.CX) == 0
     assert c.n_gates_of_type(OpType.ZZMax) == 3
 
+    c = Circuit(2).add_gate(OpType.TK2, [0.5, 0.5, 0.5], [0, 1])
+    Transform.DecomposeTK2(False, ZZPhase_fidelity=0.8).apply(c)
+    assert c.n_gates_of_type(OpType.CX) == 0
+    assert c.n_gates_of_type(OpType.ZZMax) == 3
+
+    c = Circuit(2).add_gate(OpType.TK2, [0.5, 0.5, 0.5], [0, 1])
+    Transform.DecomposeTK2(False, ZZPhase_fidelity=lambda _: 0.8).apply(c)
+    assert c.n_gates_of_type(OpType.CX) == 0
+    assert c.n_gates_of_type(OpType.ZZMax) == 3
+
 
 def test_fidelity_KAK() -> None:
     c = get_KAK_test_circuit()

diff --git a/tket/src/Transformations/Decomposition.cpp b/tket/src/Transformations/Decomposition.cpp
@@ -865,8 +865,8 @@ Transform decompose_TK2(const TwoQbFidelities &fid, bool allow_swaps) {
   }
   if (fid.ZZMax_fidelity && fid.ZZPhase_fidelity) {
     double ZZPhase_half = std::visit(
-        overloaded{// Half of the provided Value.
-                   [](double arg) { return arg * .5; },
+        overloaded{// A constant value.
+                   [](double arg) { return arg; },
                    // A value depending on the input.
                    [](std::function<double(double)> arg) { return (arg)(.5); }},
         *fid.ZZPhase_fidelity);