port NegativeExpr to use the try_to_proto / try_from_proto hooks (#22483)

## Which issue does this PR close?

- Closes #22426 

## Rationale for this change

This change is part of the per-expression proto hooks migration #22418.
I moved the serialization and deserialization of `NegativeExpr` into its
proto hooks, keeping it aligned with the new pattern used by migrated
physical expressions and reducing special-case branching in the shared
conversion code.

## What changes are included in this PR?

- Added `try_to_proto` and `try_from_proto` to `NegativeExpr`
- Removed the central `NegativeExpr` serialization branch
- Updated `physical_plan/from_proto.rs` to route physical proto decode
through `try_from_proto`

## Are these changes tested?

Yes. This PR is verified by running

- `cargo fmt --all -- --check`
- `cargo check -p datafusion-physical-expr --features proto`
- `cargo check -p datafusion-proto`
- `cargo test -p datafusion-proto --test proto_integration
roundtrip_physical_plan`
- `cargo test -p datafusion-proto --test proto_integration
roundtrip_physical_expr`
- `git diff --check`

## Are there any user-facing changes?

No user-facing changes are intended.

---------

Co-authored-by: kevinhong <kevinhong@cw.com.tw>

Author: kevinhongzl

datafusion/physical-expr/src/expressions/negative.rs

@@ -174,6 +174,43 @@ impl PhysicalExpr for NegativeExpr {
         self.arg.fmt_sql(f)?;
         write!(f, ")")
     }
+
+    #[cfg(feature = "proto")]
+    fn try_to_proto(
+        &self,
+        ctx: &datafusion_physical_expr_common::physical_expr::proto_encode::PhysicalExprEncodeCtx<'_>,
+    ) -> Result<Option<datafusion_proto_models::protobuf::PhysicalExprNode>> {
+        use datafusion_proto_models::protobuf;
+
+        Ok(Some(protobuf::PhysicalExprNode {
+            expr_id: None,
+            expr_type: Some(protobuf::physical_expr_node::ExprType::Negative(Box::new(
+                protobuf::PhysicalNegativeNode {
+                    expr: Some(Box::new(ctx.encode_child(&self.arg)?)),
+                },
+            ))),
+        }))
+    }
+}
+
+#[cfg(feature = "proto")]
+impl NegativeExpr {
+    /// Reconstruct a [`NegativeExpr`] from its protobuf representation.
+    pub fn try_from_proto(
+        node: &datafusion_proto_models::protobuf::PhysicalExprNode,
+        ctx: &datafusion_physical_expr_common::physical_expr::proto_decode::PhysicalExprDecodeCtx<'_>,
+    ) -> Result<Arc<dyn PhysicalExpr>> {
+        use datafusion_proto_models::protobuf;
+
+        let expr = match &node.expr_type {
+            Some(protobuf::physical_expr_node::ExprType::Negative(n)) => {
+                ctx.decode_required_expression(n.expr.as_deref(), "NegativeExpr", "expr")?
+            }
+            _ => return internal_err!("PhysicalExprNode is not a Negative"),
+        };
+
+        Ok(Arc::new(NegativeExpr::new(expr)))
+    }
 }
 
 /// Creates a unary expression NEGATIVE
@@ -402,3 +439,111 @@ mod tests {
         Ok(())
     }
 }
+
+#[cfg(all(test, feature = "proto"))]
+mod proto_tests {
+    use super::*;
+    use crate::expressions::{Column, col};
+    use crate::proto_test_util::{
+        StubDecoder, StubEncoder, UnreachableDecoder, column_node,
+    };
+    use arrow::datatypes::Field;
+    use datafusion_common::DataFusionError;
+    use datafusion_physical_expr_common::physical_expr::proto_decode::PhysicalExprDecodeCtx;
+    use datafusion_physical_expr_common::physical_expr::proto_encode::PhysicalExprEncodeCtx;
+    use datafusion_proto_models::protobuf::{
+        PhysicalExprNode, PhysicalNegativeNode, physical_expr_node,
+    };
+
+    /// Build a `NegativeExpr` proto node with the given children.
+    fn negative_node(expr: Option<Box<PhysicalExprNode>>) -> PhysicalExprNode {
+        PhysicalExprNode {
+            expr_id: None,
+            expr_type: Some(physical_expr_node::ExprType::Negative(Box::new(
+                PhysicalNegativeNode { expr },
+            ))),
+        }
+    }
+
+    /// A `NegativeExpr` over a column of type Int32.
+    fn negative_fixture() -> NegativeExpr {
+        let schema = Schema::new(vec![Field::new("a", DataType::Int32, true)]);
+        NegativeExpr::new(col("a", &schema).unwrap())
+    }
+
+    #[test]
+    fn try_to_proto_encodes_negative_expr() {
+        let negative = negative_fixture();
+        let encoder = StubEncoder::ok();
+        let ctx = PhysicalExprEncodeCtx::new(&encoder);
+
+        let node = negative
+            .try_to_proto(&ctx)
+            .unwrap()
+            .expect("NegativeExpr should encode to Some(node)");
+
+        assert!(node.expr_id.is_none());
+        let negative_node = match node.expr_type {
+            Some(physical_expr_node::ExprType::Negative(boxed)) => *boxed,
+            other => panic!("expected a NegativeExpr node, got {other:?}"),
+        };
+        assert!(negative_node.expr.is_some());
+    }
+
+    #[test]
+    fn try_to_proto_propagates_expr_encode_error() {
+        let negative = negative_fixture();
+        let encoder = StubEncoder::failing_on(1);
+        let ctx = PhysicalExprEncodeCtx::new(&encoder);
+        let err = negative.try_to_proto(&ctx).unwrap_err();
+        assert!(matches!(err, DataFusionError::Internal(msg) if msg.contains("call 1")));
+    }
+
+    #[test]
+    fn try_from_proto_decodes_negative_expr() {
+        let node = negative_node(Some(Box::new(column_node("a"))));
+        let schema = Schema::empty();
+        let decoder = StubDecoder::ok();
+        let ctx = PhysicalExprDecodeCtx::new(&schema, &decoder);
+
+        let decoded = NegativeExpr::try_from_proto(&node, &ctx).unwrap();
+        let negative = decoded
+            .downcast_ref::<NegativeExpr>()
+            .expect("decoded expr should be a NegativeExpr");
+        assert!(negative.arg().downcast_ref::<Column>().is_some());
+    }
+
+    #[test]
+    fn try_from_proto_rejects_non_negative_node() {
+        let node = column_node("a");
+        let schema = Schema::empty();
+        let decoder = UnreachableDecoder;
+        let ctx = PhysicalExprDecodeCtx::new(&schema, &decoder);
+        let err = NegativeExpr::try_from_proto(&node, &ctx).unwrap_err();
+        assert!(
+            matches!(err, DataFusionError::Internal(msg) if msg.contains("PhysicalExprNode is not a Negative"))
+        );
+    }
+
+    #[test]
+    fn try_from_proto_rejects_missing_expr() {
+        let node = negative_node(None);
+        let schema = Schema::empty();
+        let decoder = UnreachableDecoder;
+        let ctx = PhysicalExprDecodeCtx::new(&schema, &decoder);
+        let err = NegativeExpr::try_from_proto(&node, &ctx).unwrap_err();
+        assert!(
+            matches!(err, DataFusionError::Internal(msg) if msg.contains("NegativeExpr is missing required field 'expr'"))
+        );
+    }
+
+    #[test]
+    fn try_from_proto_propagates_expr_decode_error() {
+        let node = negative_node(Some(Box::new(column_node("a"))));
+        let schema = Schema::empty();
+        let decoder = StubDecoder::failing_on(1);
+        let ctx = PhysicalExprDecodeCtx::new(&schema, &decoder);
+        let err = NegativeExpr::try_from_proto(&node, &ctx).unwrap_err();
+        assert!(matches!(err, DataFusionError::Internal(msg) if msg.contains("call 1")));
+    }
+}

datafusion/proto/src/physical_plan/from_proto.rs

@@ -319,15 +319,7 @@ pub fn parse_physical_expr_with_converter(
             input_schema,
             proto_converter,
         )?)),
-        ExprType::Negative(e) => {
-            Arc::new(NegativeExpr::new(parse_required_physical_expr(
-                e.expr.as_deref(),
-                ctx,
-                "expr",
-                input_schema,
-                proto_converter,
-            )?))
-        }
+        ExprType::Negative(_) => NegativeExpr::try_from_proto(proto, &decode_ctx)?,
         ExprType::InList(_) => InListExpr::try_from_proto(proto, &decode_ctx)?,
         ExprType::Case(e) => Arc::new(CaseExpr::try_new(
             e.expr

datafusion/proto/src/physical_plan/to_proto.rs

@@ -37,7 +37,7 @@ use datafusion_physical_expr::window::{SlidingAggregateWindowExpr, StandardWindo
 use datafusion_physical_expr_common::sort_expr::PhysicalSortExpr;
 use datafusion_physical_plan::expressions::{
     CaseExpr, CastExpr, DynamicFilterPhysicalExpr, IsNotNullExpr, IsNullExpr, Literal,
-    NegativeExpr, NotExpr, TryCastExpr, UnKnownColumn,
+    NotExpr, TryCastExpr, UnKnownColumn,
 };
 use datafusion_physical_plan::joins::HashExpr;
 use datafusion_physical_plan::udaf::AggregateFunctionExpr;
@@ -387,17 +387,6 @@ pub fn serialize_physical_expr_with_converter(
                 }),
             )),
         })
-    } else if let Some(expr) = expr.downcast_ref::<NegativeExpr>() {
-        Ok(protobuf::PhysicalExprNode {
-            expr_id,
-            expr_type: Some(protobuf::physical_expr_node::ExprType::Negative(Box::new(
-                protobuf::PhysicalNegativeNode {
-                    expr: Some(Box::new(
-                        proto_converter.physical_expr_to_proto(expr.arg(), codec)?,
-                    )),
-                },
-            ))),
-        })
     } else if let Some(lit) = expr.downcast_ref::<Literal>() {
         Ok(protobuf::PhysicalExprNode {
             expr_id,