fix loading field message when dependency is more than one step

Author: oliversun9

buf.gen.yaml

@@ -6,6 +6,7 @@ managed:
     except:
       - buf.build/envoyproxy/protoc-gen-validate
       - buf.build/bufbuild/protovalidate
+      - buf.build/googleapis/googleapis
 plugins:
   - plugin: buf.build/protocolbuffers/go:v1.31.0
     out: internal/gen

internal/evaluator/builder.go

@@ -268,7 +268,7 @@ func (bldr *Builder) processFieldExpressions(
 	var opts []cel.EnvOption
 	if fieldDesc.Kind() == protoreflect.MessageKind {
 		opts = []cel.EnvOption{
-			cel.TypeDescs(fieldDesc.Message().ParentFile()),
+            cel.Types(dynamicpb.NewMessage(fieldDesc.Message())),
 			cel.Variable("this", cel.ObjectType(string(fieldDesc.Message().FullName()))),
 		}
 	} else {

internal/gen/tests/example/v1/validations.pb.go

@@ -16,3 +16,8 @@ deps:
     repository: protoc-gen-validate
     commit: eac44469a7af47e7839a7f1f3d7ac004
     digest: shake256:0feabcde01b6b11e3c75a5e3f807968d5995626546f39c37e5d4205892b3a59cced0ed83b35a2eb9e6dddd3309660ad46b737c9dcd224b425de0a6654ce04417
+  - remote: buf.build
+    owner: googleapis
+    repository: googleapis
+    commit: 28151c0d0a1641bf938a7672c500e01d
+    digest: shake256:49215edf8ef57f7863004539deff8834cfb2195113f0b890dd1f67815d9353e28e668019165b9d872395871eeafcbab3ccfdb2b5f11734d3cca95be9e8d139de

proto/buf.lock

@@ -3,6 +3,7 @@ deps:
   - buf.build/bufbuild/protovalidate
   - buf.build/bufbuild/protovalidate-testing
   - buf.build/envoyproxy/protoc-gen-validate
+  - buf.build/googleapis/googleapis
 breaking:
   use:
     - FILE

proto/buf.yaml

@@ -17,6 +17,7 @@ syntax = "proto3";
 package tests.example.v1;
 
 import "buf/validate/validate.proto";
+import "google/geo/type/viewport.proto";
 import "google/protobuf/field_mask.proto";
 
 message HasMsgExprs {
@@ -131,3 +132,11 @@ message TransitiveFieldConstraint {
     expression: "has(this.paths)",
   }];
 }
+
+message MultipleStepsTransitiveFieldConstraints {
+  google.geo.type.Viewport viewport = 1 [(buf.validate.field).cel = {
+    id: "viewport.low.latitude",
+    message: "viewport's low point's latitude must be greater than 10.0 degrees",
+    expression: "this.low.latitude > 10.0"
+  }];
+}

proto/tests/example/v1/validations.proto

@@ -20,6 +20,8 @@ import (
 	pb "github.com/bufbuild/protovalidate-go/internal/gen/tests/example/v1"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"google.golang.org/genproto/googleapis/geo/type/viewport"
+	"google.golang.org/genproto/googleapis/type/latlng"
 	"google.golang.org/protobuf/types/known/fieldmaskpb"
 )
 
@@ -135,3 +137,18 @@ func TestValidator_Validate_TransitiveFieldConstraints(t *testing.T) {
 	err = val.Validate(msg)
 	require.NoError(t, err)
 }
+
+func TestValidator_Validate_MultipleStepsTransitiveFieldConstraints(t *testing.T) {
+	t.Parallel()
+	val, err := New()
+	require.NoError(t, err)
+	msg := &pb.MultipleStepsTransitiveFieldConstraints{
+        Viewport: &viewport.Viewport{
+            Low: &latlng.LatLng{
+                Latitude: 30.0,
+            },
+        },
+    }
+	err = val.Validate(msg)
+	require.NoError(t, err)
+}