Add tests for ScanArgs and change clone behavior of ScanArgs.from_node

aesara/scan/utils.py

@@ -895,10 +895,21 @@ class ScanArgs:
     nested_list_fields = ("inner_in_mit_mot", "inner_in_mit_sot", "inner_out_mit_mot")
 
     def __init__(
-        self, outer_inputs, outer_outputs, _inner_inputs, _inner_outputs, info
+        self,
+        outer_inputs,
+        outer_outputs,
+        _inner_inputs,
+        _inner_outputs,
+        info,
+        clone=True,
     ):
         self.n_steps = outer_inputs[0]
-        rval = reconstruct_graph(_inner_inputs, _inner_outputs, "")
+
+        if clone:
+            rval = reconstruct_graph(_inner_inputs, _inner_outputs, "")
+        else:
+            rval = (_inner_inputs, _inner_outputs)
+
         if info["as_while"]:
             self.cond = [rval[1][-1]]
             inner_outputs = rval[1][:-1]
@@ -1019,13 +1030,18 @@ class ScanArgs:
                 self.other_info[k] = info[k]
 
     @staticmethod
-    def from_node(node):
+    def from_node(node, clone=False):
         from aesara.scan.op import Scan
 
         if not isinstance(node.op, Scan):
             raise TypeError("{} is not a Scan node".format(node))
         return ScanArgs(
-            node.inputs, node.outputs, node.op.inputs, node.op.outputs, node.op.info
+            node.inputs,
+            node.outputs,
+            node.op.inputs,
+            node.op.outputs,
+            node.op.info,
+            clone=clone,
         )
 
     @classmethod
@@ -1242,8 +1258,6 @@ class ScanArgs:
         return field_info
 
     def get_dependent_nodes(self, i, seen=None):
-        from aesara.graph import inputs as at_inputs
-
         if seen is None:
             seen = {i}
         else:
@@ -1302,7 +1316,7 @@ class ScanArgs:
             # If starting from an inner-input, then we need to find any
             # inner-outputs that depend on it.
             for out_n in self.inner_outputs:
-                if i in at_inputs([out_n]):
+                if i in graph_inputs([out_n]):
                     if out_n not in seen:
                         dependent_nodes.add(out_n)