Add gomega matcher to compare and diff protoreflect.Value objects

pkg/test/testutil/equal.go

@@ -2,6 +2,7 @@ package testutil
 
 import (
 	"fmt"
+	"slices"
 	"strings"
 
 	"github.com/google/go-cmp/cmp"
@@ -11,6 +12,7 @@ import (
 	"google.golang.org/grpc/status"
 	"google.golang.org/protobuf/encoding/prototext"
 	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/reflect/protoreflect"
 	"google.golang.org/protobuf/testing/protocmp"
 )
 
@@ -65,6 +67,84 @@ func (matcher *ProtoMatcher) Matches(x interface{}) bool {
 	return success
 }
 
+func ProtoValueEqual(expected protoreflect.Value) *ProtoValueMatcher {
+	return &ProtoValueMatcher{
+		Expected: expected,
+	}
+}
+
+type ProtoValueMatcher struct {
+	Expected protoreflect.Value
+}
+
+func (matcher *ProtoValueMatcher) Match(actual any) (success bool, err error) {
+	if actual == nil && !matcher.Expected.IsValid() {
+		return false, fmt.Errorf("Refusing to compare <nil> to <nil>.\nBe explicit and use BeNil() instead.  This is to avoid mistakes where both sides of an assertion are erroneously uninitialized")
+	}
+	if actual, ok := actual.(protoreflect.Value); !ok {
+		return false, fmt.Errorf("ProtoValueMatcher expects a protoreflect.Value. Got:\n%s", format.Object(actual, 1))
+	} else {
+		return matcher.Expected.Equal(actual), nil
+	}
+}
+
+func (matcher *ProtoValueMatcher) FailureMessage(actual any) (message string) {
+	return fmt.Sprintf("Expected\n%s\n%s\n%s",
+		format.IndentString(humanizeProtoreflectValue(actual.(protoreflect.Value)), 1),
+		"to equal",
+		format.IndentString(humanizeProtoreflectValue(matcher.Expected), 1),
+	)
+}
+
+func (matcher *ProtoValueMatcher) NegatedFailureMessage(actual any) (message string) {
+	return fmt.Sprintf("Expected\n%s\n%s\n%s",
+		format.IndentString(humanizeProtoreflectValue(actual.(protoreflect.Value)), 1),
+		"not to equal",
+		format.IndentString(humanizeProtoreflectValue(matcher.Expected), 1),
+	)
+}
+
+func humanizeProtoreflectValue(v protoreflect.Value) string {
+	switch v := v.Interface().(type) {
+	case nil:
+		return "nil"
+	case bool, int32, int64, uint32, uint64, float32, float64, string:
+		return fmt.Sprintf("%v", v)
+	case []byte:
+		return string(v)
+	case protoreflect.EnumNumber:
+		return fmt.Sprintf("%v", v)
+	case protoreflect.Message:
+		return prototext.Format(v.Interface())
+	case protoreflect.List:
+		builder := strings.Builder{}
+		builder.WriteString("[\n")
+		for i := 0; i < v.Len(); i++ {
+			fmt.Fprintf(&builder, "  %s\n", humanizeProtoreflectValue(v.Get(i)))
+		}
+		builder.WriteString("]")
+		return builder.String()
+	case protoreflect.Map:
+		builder := strings.Builder{}
+		builder.WriteString("{\n")
+		kvs := []string{}
+		v.Range(func(mk protoreflect.MapKey, v protoreflect.Value) bool {
+			kvs = append(kvs, fmt.Sprintf("%s: %s", mk.String(), humanizeProtoreflectValue(v)))
+			return true
+		})
+		slices.Sort(kvs)
+		for _, kv := range kvs {
+			builder.WriteString(kv)
+		}
+		builder.WriteString("}")
+		return builder.String()
+	case protoreflect.ProtoMessage:
+		panic(fmt.Sprintf("invalid proto.Message(%T) type, expected a protoreflect.Message type", v))
+	default:
+		panic(fmt.Sprintf("invalid type: %T", v))
+	}
+}
+
 type StatusCodeMatcher struct {
 	Expected any
 	matchMsg types.GomegaMatcher