From 21daf4e0fb82b9024ac1a7b57a3a815ba9f1ba68 Mon Sep 17 00:00:00 2001
From: "Brandon T. Willard" <brandonwillard@users.noreply.github.com>
Date: Sat, 17 Oct 2020 01:12:31 -0500
Subject: [PATCH] Validate test values using a tensor's type

---
 tests/gof/test_compute_test_value.py | 14 ++++++++------
 theano/gof/graph.py                  |  2 +-
 theano/gof/utils.py                  | 17 +++++++++++++++++
 theano/tensor/opt.py                 |  5 ++++-
 4 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/tests/gof/test_compute_test_value.py b/tests/gof/test_compute_test_value.py
index b25991f4a2..34c4c7808b 100644
--- a/tests/gof/test_compute_test_value.py
+++ b/tests/gof/test_compute_test_value.py
@@ -167,14 +167,16 @@ def test_constant(self):
 
     @theano.change_flags(compute_test_value="raise")
     def test_incorrect_type(self):
-        x = tt.fmatrix("x")
-        # Incorrect dtype (float64) for test_value
-        x.tag.test_value = np.random.rand(3, 4)
-        y = tt.dmatrix("y")
-        y.tag.test_value = np.random.rand(4, 5)
 
+        x = tt.vector("x")
         with pytest.raises(TypeError):
-            tt.dot(x, y)
+            # Incorrect shape for test value
+            x.tag.test_value = np.empty((2, 2))
+
+        x = tt.fmatrix("x")
+        with pytest.raises(TypeError):
+            # Incorrect dtype (float64) for test value
+            x.tag.test_value = np.random.rand(3, 4)
 
     @theano.change_flags(compute_test_value="raise")
     def test_overided_function(self):
diff --git a/theano/gof/graph.py b/theano/gof/graph.py
index 881a45a08c..f36dd122be 100644
--- a/theano/gof/graph.py
+++ b/theano/gof/graph.py
@@ -383,7 +383,7 @@ class Variable(Node):
     def __init__(self, type, owner=None, index=None, name=None):
         super(Variable, self).__init__()
 
-        self.tag = utils.Scratchpad()
+        self.tag = utils.ValidatingScratchpad("test_value", type.filter)
 
         self.type = type
         if owner is not None and not isinstance(owner, Apply):
diff --git a/theano/gof/utils.py b/theano/gof/utils.py
index 261702756f..bd5e333a8e 100644
--- a/theano/gof/utils.py
+++ b/theano/gof/utils.py
@@ -259,6 +259,23 @@ def info(self):
             print("  %s: %s" % (k, v))
 
 
+class ValidatingScratchpad(Scratchpad):
+    """This `Scratchpad` validates attribute values."""
+
+    def __init__(self, attr, attr_filter):
+        super().__init__()
+
+        object.__setattr__(self, "attr", attr)
+        object.__setattr__(self, "attr_filter", attr_filter)
+
+    def __setattr__(self, attr, obj):
+
+        if getattr(self, "attr", None) == attr:
+            obj = self.attr_filter(obj)
+
+        return object.__setattr__(self, attr, obj)
+
+
 class D:
     def __init__(self, **d):
         self.__dict__.update(d)
diff --git a/theano/tensor/opt.py b/theano/tensor/opt.py
index 97ddf04f69..00e61ea548 100644
--- a/theano/tensor/opt.py
+++ b/theano/tensor/opt.py
@@ -7743,7 +7743,10 @@ def local_fuse(node):
                                 if tv.size > 0:
                                     tmp.tag.test_value = tv.flatten()[0]
                                 else:
-                                    tmp.tag.test_value = tv
+                                    _logger.warning(
+                                        "Cannot construct a scalar test value"
+                                        " from a test value with no size: {}".format(ii)
+                                    )
                             except AttributeError:
                                 pass