Handle constants in XTensorType.filter_variable

pytensor/xtensor/type.py

@@ -103,7 +103,7 @@ class XTensorType(Type, HasDataType, HasShape):
         if not isinstance(other, Variable):
             # The value is not a Variable: we cast it into
             # a Constant of the appropriate Type.
-            other = xtensor_constant(other)
+            other = XTensorConstant(type=self, data=other)
 
         if self.is_super(other.type):
             return other

tests/xtensor/test_type.py

@@ -10,7 +10,7 @@ from xarray import DataArray
 from pytensor.graph.basic import equal_computations
 from pytensor.tensor import as_tensor, specify_shape, tensor
 from pytensor.xtensor import xtensor
-from pytensor.xtensor.type import XTensorType, as_xtensor
+from pytensor.xtensor.type import XTensorConstant, XTensorType, as_xtensor
 
 
 def test_xtensortype():
@@ -77,6 +77,37 @@ def test_xtensortype_filter_variable():
         x.type.filter_variable(z4)
 
 
+def test_xtensortype_filter_variable_constant():
+    x = xtensor("x", dims=("a", "b"), shape=(2, 3), dtype="float32")
+
+    valid_x = np.zeros((2, 3), dtype="float32")
+    res = x.type.filter_variable(valid_x)
+    assert isinstance(res, XTensorConstant) and res.type == x.type
+
+    # Upcasting allowed
+    valid_x = np.zeros((2, 3), dtype="float16")
+    res = x.type.filter_variable(valid_x)
+    assert isinstance(res, XTensorConstant) and res.type == x.type
+
+    valid_x = np.zeros((2, 3), dtype="int16")
+    res = x.type.filter_variable(valid_x)
+    assert isinstance(res, XTensorConstant) and res.type == x.type
+
+    # Downcasting not allowed
+    invalid_x = np.zeros((2, 3), dtype="float64")
+    with pytest.raises(TypeError):
+        x.type.filter_variable(invalid_x)
+
+    invalid_x = np.zeros((2, 3), dtype="int32")
+    with pytest.raises(TypeError):
+        x.type.filter_variable(invalid_x)
+
+    # non_array types are fine
+    valid_x = [[0, 0, 0], [0, 0, 0]]
+    res = x.type.filter_variable(valid_x)
+    assert isinstance(res, XTensorConstant) and res.type == x.type
+
+
 def test_xtensor_constant():
     x = as_xtensor(DataArray(np.ones((2, 3)), dims=("a", "b")))
     assert x.type == XTensorType(dtype="float64", dims=("a", "b"), shape=(2, 3))