feat(float_fusing): restrict to scalars before supporting tensors

tests/common/optimization/test_float_fusing.py

@@ -1,5 +1,6 @@
 """Test file for float subgraph fusing"""
 
+import random
 from inspect import signature
 
 import numpy
@@ -7,7 +8,7 @@ import pytest
 
 from concrete.common.data_types.integers import Integer
 from concrete.common.optimization.topological import fuse_float_operations
-from concrete.common.values import EncryptedScalar
+from concrete.common.values import EncryptedScalar, EncryptedTensor
 from concrete.numpy import tracing
 from concrete.numpy.tracing import trace_numpy_function
 
@@ -116,6 +117,35 @@ def test_fuse_float_operations(function_to_trace, fused, input_):
     assert function_to_trace(*inputs) == op_graph(*inputs)
 
 
+# TODO: #199 To be removed when doing tensor management
+def test_tensor_no_fuse():
+    """Test case to verify float fusing is only applied on functions on scalars."""
+
+    ndim = random.randint(1, 3)
+    tensor_shape = tuple(random.randint(1, 10) for _ in range(ndim + 1))
+
+    def tensor_no_fuse(x):
+        intermediate = x.astype(numpy.float64)
+        intermediate = intermediate.astype(numpy.int32)
+        return intermediate + numpy.ones(tensor_shape)
+
+    function_to_trace = tensor_no_fuse
+    params_names = signature(function_to_trace).parameters.keys()
+
+    op_graph = trace_numpy_function(
+        function_to_trace,
+        {
+            param_name: EncryptedTensor(Integer(32, True), shape=tensor_shape)
+            for param_name in params_names
+        },
+    )
+    orig_num_nodes = len(op_graph.graph)
+    fuse_float_operations(op_graph)
+    fused_num_nodes = len(op_graph.graph)
+
+    assert orig_num_nodes == fused_num_nodes
+
+
 def test_fuse_float_operations_correctness():
     """Test functions which are in tracing.NPTracer.LIST_OF_SUPPORTED_UFUNC
     with fuse_float_operations."""