commit

private/pkg/protosourcepath/protosourcepath.go

diff --git a/private/pkg/protosourcepath/protosourcepath.go b/private/pkg/protosourcepath/protosourcepath.go
new file mode 100644
index 0000000..69d9c58
--- /dev/null
+++ b/private/pkg/protosourcepath/protosourcepath.go
@@ -0,0 +1,65 @@
+// Copyright 2020-2024 Buf Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package protosourcepath
+
+import (
+	"errors"
+	"fmt"
+
+	"google.golang.org/protobuf/reflect/protoreflect"
+)
+
+const (
+	fileDescriptorProtoMessageTypeTag = int32(4)
+	descriptorProtoNameTag            = int32(1)
+)
+
+var (
+	errInvalidSourcePath = errors.New("invalid sourcepa")
+)
+
+// GetAssociatedSourcePaths gets the associated source paths.
+func GetAssociatedSourcePaths(sourcePath protoreflect.SourcePath) ([]protoreflect.SourcePath, error) {
+	if len(sourcePath) == 0 {
+		return nil, nil
+	}
+	switch sourcePath[0] {
+	case fileDescriptorProtoMessageTypeTag:
+		switch len(sourcePath) {
+		case 1:
+			return nil, newInvalidSourcePathError(sourcePath, "expected message_type index")
+		case 2:
+			// No additional source paths.
+			// We could argue that name is an additional source path, but let's just go with parents for now.
+			return []protoreflect.SourcePath{
+				sourcePath,
+			}, nil
+		case 3:
+			switch sourcePath[2] {
+			case descriptorProtoNameTag:
+				return []protoreflect.SourcePath{
+					sourcePath,
+					// Also include message
+					sourcePath[0:2],
+				}, nil
+			}
+		}
+	}
+	return nil, newInvalidSourcePathError(sourcePath, "unrecognized")
+}
+
+func newInvalidSourcePathError(sourcePath protoreflect.SourcePath, format string, args ...any) error {
+	return fmt.Errorf("invalid protoreflect.SourcePath %v: %s", sourcePath, fmt.Sprintf(format, args...))
+}

private/pkg/protosourcepath/usage.gen.go

diff --git a/private/pkg/protosourcepath/usage.gen.go b/private/pkg/protosourcepath/usage.gen.go
new file mode 100644
index 0000000..0f413c0
--- /dev/null
+++ b/private/pkg/protosourcepath/usage.gen.go
@@ -0,0 +1,19 @@
+// Copyright 2020-2024 Buf Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Generated. DO NOT EDIT.
+
+package protosourcepath
+
+import _ "github.com/bufbuild/buf/private/usage"