Test validation of cyclic graph + local consts, doc failures

src/hugr/validate.rs

@@ -392,6 +392,15 @@ impl<'a> ValidationContext<'a> {
 
         let postorder = DfsPostOrder::new(&region, entry_node);
         let nodes_visited = postorder.iter(&region).filter(|n| *n != parent).count();
+        let _module_op_count = self
+            .hugr
+            .children(parent)
+            .filter(|n| OpTag::ModuleOp.contains(self.hugr.get_optype(*n).tag()))
+            .count();
+        // XXX TODO FIXME we should take _module_op_count off the child_count below,
+        // because e.g. Const nodes should not be reached by the DfsPostOrder in a forwards
+        // traversal. (Currently this would break tests because the traversal goes both forwards
+        // AND backwards).
         if nodes_visited != self.hugr.hierarchy.child_count(parent.index) {
             return Err(ValidationError::NotABoundedDag {
                 node: parent,
@@ -731,7 +740,7 @@ mod test {
     use super::*;
     use crate::builder::{BuildError, ModuleBuilder};
     use crate::builder::{Container, Dataflow, DataflowSubContainer, HugrBuilder};
-    use crate::hugr::HugrMut;
+    use crate::hugr::{HugrError, HugrMut};
     use crate::ops::dataflow::IOTrait;
     use crate::ops::{self, ConstValue, LeafOp, OpType};
     use crate::types::{ClassicType, LinearType, Signature};
@@ -1067,6 +1076,112 @@ mod test {
         );
     }
 
+    #[test]
+    fn test_ext_edge() -> Result<(), HugrError> {
+        let mut h = Hugr::new(ops::DFG {
+            signature: Signature::new_df(type_row![B, B], type_row![B]),
+        });
+        let input = h.add_op_with_parent(h.root(), ops::Input::new(type_row![B, B]))?;
+        let output = h.add_op_with_parent(h.root(), ops::Output::new(type_row![B]))?;
+        // Nested DFG B -> B
+        let sub_dfg = h.add_op_with_parent(
+            h.root(),
+            ops::DFG {
+                signature: Signature::new_linear(type_row![B]),
+            },
+        )?;
+        // this Xor has its 2nd input unconnected
+        let sub_op = {
+            let sub_input = h.add_op_with_parent(sub_dfg, ops::Input::new(type_row![B]))?;
+            let sub_output = h.add_op_with_parent(sub_dfg, ops::Output::new(type_row![B]))?;
+            let sub_op = h.add_op_with_parent(sub_dfg, LeafOp::Xor)?;
+            h.connect(sub_input, 0, sub_op, 0)?;
+            h.connect(sub_op, 0, sub_output, 0)?;
+            sub_op
+        };
+
+        h.connect(input, 0, sub_dfg, 0)?;
+        h.connect(sub_dfg, 0, output, 0)?;
+
+        assert_matches!(h.validate(), Err(ValidationError::UnconnectedPort { .. }));
+
+        h.connect(input, 1, sub_op, 1)?;
+        assert_matches!(
+            h.validate(),
+            Err(ValidationError::InterGraphEdgeError(
+                InterGraphEdgeError::MissingOrderEdge { .. }
+            ))
+        );
+        //Order edge. There must be an easier way to do this?
+        h.connect(
+            input,
+            h.get_optype(input)
+                .other_port_index(Direction::Outgoing)
+                .unwrap()
+                .index(),
+            sub_dfg,
+            h.get_optype(sub_dfg)
+                .other_port_index(Direction::Incoming)
+                .unwrap()
+                .index(),
+        )?;
+        h.validate().unwrap();
+        Ok(())
+    }
+
+    #[test]
+    fn test_local_const() -> Result<(), HugrError> {
+        let mut h = Hugr::new(ops::DFG {
+            signature: Signature::new_df(type_row![B], type_row![B]),
+        });
+        let input = h.add_op_with_parent(h.root(), ops::Input::new(type_row![B]))?;
+        let output = h.add_op_with_parent(h.root(), ops::Output::new(type_row![B]))?;
+        let xor = h.add_op_with_parent(h.root(), LeafOp::Xor)?;
+        h.connect(input, 0, xor, 0)?;
+        h.connect(xor, 0, output, 0)?;
+        assert_eq!(
+            h.validate(),
+            Err(ValidationError::UnconnectedPort {
+                node: xor,
+                port: Port::new_incoming(1),
+                port_kind: EdgeKind::Value(B)
+            })
+        );
+        // Second input of Xor from a constant
+        let cst =
+            h.add_op_with_parent(h.root(), ops::Const(ConstValue::Int { width: 1, value: 1 }))?;
+        let lcst = h.add_op_with_parent(
+            h.root(),
+            ops::LoadConstant {
+                datatype: ClassicType::Int(1),
+            },
+        )?;
+        h.connect(cst, 0, lcst, 0)?;
+        h.connect(lcst, 0, xor, 1)?;
+        // XXX TODO FIXME This should fail, but succeeds:
+        h.validate().unwrap();
+        // Now include the LoadConstant node in the causal cone
+        h.add_other_edge(input, lcst)?;
+        h.validate().unwrap();
+        Ok(())
+    }
+
+    #[test]
+    fn test_cyclic() -> Result<(), HugrError> {
+        let mut h = Hugr::new(ops::DFG {
+            signature: Signature::new_df(type_row![Q], type_row![Q]),
+        });
+        let input = h.add_op_with_parent(h.root(), ops::Input::new(type_row![Q]))?;
+        let output = h.add_op_with_parent(h.root(), ops::Output::new(type_row![Q]))?;
+        let cx = h.add_op_with_parent(h.root(), LeafOp::CX)?;
+        h.connect(input, 0, cx, 0)?;
+        h.connect(cx, 0, output, 0)?;
+        h.connect(cx, 1, cx, 1)?;
+        // TODO FIXME We should get an error here, but this passes ATM :-(
+        h.validate().unwrap();
+        Ok(())
+    }
+
     #[test]
     /// A wire with no resource requirements is wired into a node which has
     /// [A,B] resources required on its inputs and outputs. This could be fixed