Implement MessageOneof rule (#254)

This implements the `MessageOneof` rule specified in
bufbuild/protovalidate#377

---------

Co-authored-by: Timo Stamm <[email protected]>

Author: smaye81

Makefile

@@ -16,7 +16,7 @@ GOLANGCI_LINT_VERSION ?= v2.1.2
 # Set to use a different version of protovalidate-conformance.
 # Should be kept in sync with the version referenced in buf.yaml and
 # 'buf.build/gen/go/bufbuild/protovalidate/protocolbuffers/go' in go.mod.
-CONFORMANCE_VERSION ?= v1.0.0-rc.1
+CONFORMANCE_VERSION ?= v1.0.0-rc.2
 
 .PHONY: help
 help: ## Describe useful make targets

buf.yaml

@@ -2,8 +2,8 @@ version: v2
 modules:
   - path: proto
 deps:
-  - buf.build/bufbuild/protovalidate:v1.0.0-rc.1
-  - buf.build/bufbuild/protovalidate-testing:v1.0.0-rc.1
+  - buf.build/bufbuild/protovalidate:v1.0.0-rc.2
+  - buf.build/bufbuild/protovalidate-testing:v1.0.0-rc.2
 lint:
   use:
     - STANDARD

builder.go

@@ -127,6 +127,25 @@ func (bldr *builder) buildMessage(
 		return
 	}
 
+	oneofRules := msgRules.GetOneof()
+	for _, rule := range oneofRules {
+		fdescs := make([]protoreflect.FieldDescriptor, 0, len(rule.GetFields()))
+		for _, name := range rule.GetFields() {
+			fdesc := desc.Fields().ByName(protoreflect.Name(name))
+			if fdesc == nil {
+				msgEval.Err = &CompilationError{cause: fmt.Errorf(
+					"field %q not found in message %s", name, desc.FullName())}
+			} else {
+				fdescs = append(fdescs, fdesc)
+			}
+		}
+		oneofEval := &oneofEvaluator{
+			Fields:   fdescs,
+			Required: rule.GetRequired(),
+		}
+		msgEval.AppendNested(oneofEval)
+	}
+
 	steps := []func(
 		desc protoreflect.MessageDescriptor,
 		msgRules *validate.MessageRules,

go.mod

@@ -3,7 +3,7 @@ module buf.build/go/protovalidate
 go 1.23.0
 
 require (
-	buf.build/gen/go/bufbuild/protovalidate/protocolbuffers/go v1.36.6-00000000000000-c7344d9f5dae.1
+	buf.build/gen/go/bufbuild/protovalidate/protocolbuffers/go v1.36.6-00000000000000-c6451e2c05a6.1
 	github.com/google/cel-go v0.25.0
 	github.com/stretchr/testify v1.10.0
 	google.golang.org/protobuf v1.36.6

go.sum

@@ -1,5 +1,5 @@
-buf.build/gen/go/bufbuild/protovalidate/protocolbuffers/go v1.36.6-00000000000000-c7344d9f5dae.1 h1:nmsl+LeZt89FPjFhJvd0LTaUjmLy4MDAC+XEbzXc3xU=
-buf.build/gen/go/bufbuild/protovalidate/protocolbuffers/go v1.36.6-00000000000000-c7344d9f5dae.1/go.mod h1:avRlCjnFzl98VPaeCtJ24RrV/wwHFzB8sWXhj26+n/U=
+buf.build/gen/go/bufbuild/protovalidate/protocolbuffers/go v1.36.6-00000000000000-c6451e2c05a6.1 h1:foZfk56KWDz932pQ0gr0OfM5GrEBZVJvxyBzPBkik/U=
+buf.build/gen/go/bufbuild/protovalidate/protocolbuffers/go v1.36.6-00000000000000-c6451e2c05a6.1/go.mod h1:avRlCjnFzl98VPaeCtJ24RrV/wwHFzB8sWXhj26+n/U=
 cel.dev/expr v0.23.1 h1:K4KOtPCJQjVggkARsjG9RWXP6O4R73aHeJMa/dmCQQg=
 cel.dev/expr v0.23.1/go.mod h1:hLPLo1W4QUmuYdA72RBX06QTs6MXw941piREPl3Yfiw=
 github.com/antlr4-go/antlr/v4 v4.13.0 h1:lxCg3LAv+EUK6t1i0y1V6/SLeUi0eKEKdhQAlS8TVTI=