[Test] add fork cases to RemoveIdentityOps test

tests/transformation/test_remove_identity_ops.py

@@ -77,7 +77,8 @@ def insert_identity_op(model, op, as_first_node, approx):
 @pytest.mark.parametrize("op", ["Add", "Sub", "Mul", "Div", "Identity"])
 @pytest.mark.parametrize("approx", [False, True])
 @pytest.mark.parametrize("as_first_node", [False, True])
-def test_remove_identity_ops(op, as_first_node, approx):
+@pytest.mark.parametrize("fork_before_id", [False, True])
+def test_remove_identity_ops(op, as_first_node, approx, fork_before_id):
     # set up onnx model
     inp = helper.make_tensor_value_info("inp", TensorProto.FLOAT, [1, 4, 1, 1])
     mul = helper.make_tensor_value_info("mul", TensorProto.FLOAT, [])
@@ -114,14 +115,16 @@ def test_remove_identity_ops(op, as_first_node, approx):
     model = model.transform(InferShapes())
     model = model.transform(InferDataTypes())
     idict = {"inp": inp_values}
-    odict = oxe.execute_onnx(model, idict)
-    out_before = odict["outp"]
+    odict_before = oxe.execute_onnx(model, idict)
     num_of_nodes_before = len(model.graph.node)
-
+    if fork_before_id and not as_first_node:
+        divout_vi = model.get_tensor_valueinfo("div_out")
+        model.graph.output.append(divout_vi)
+        model.graph.value_info.remove(divout_vi)
     model = model.transform(RemoveIdentityOps())
     num_of_nodes_after = len(model.graph.node)
     assert num_of_nodes_before - 1 == num_of_nodes_after
 
-    odict = oxe.execute_onnx(model, idict)
-    out_after = odict["outp"]
-    assert np.isclose(out_before, out_after, atol=1e-3).all()
+    odict_after = oxe.execute_onnx(model, idict)
+    outputs_same = [np.isclose(odict_before[tname], odict_after[tname], atol=1e-3).all() for tname in odict_before.keys()]
+    assert all(outputs_same)