From 07c233ba95ad9ee43d051fa946004ac2cd28d067 Mon Sep 17 00:00:00 2001
From: "marco.ferrer" <marco.ferrer@reddit.com>
Date: Fri, 8 Aug 2025 17:33:37 -0400
Subject: [PATCH 1/2] add support for compiling from a file registry

---
 compile.go | 31 ++++++++++++++++++-------------
 1 file changed, 18 insertions(+), 13 deletions(-)

diff --git a/compile.go b/compile.go
index bc9c95f..ce13d9e 100644
--- a/compile.go
+++ b/compile.go
@@ -33,19 +33,7 @@ func CompileFileDescriptorSet(fds *descriptorpb.FileDescriptorSet, messageName p
 	if err != nil {
 		return nil, err
 	}
-	desc, err := files.FindDescriptorByName(messageName)
-	if err != nil {
-		return nil, err
-	}
-	msgDesc, ok := desc.(protoreflect.MessageDescriptor)
-	if !ok {
-		return nil, protoregistry.NotFound
-	}
-
-	// Allow the caller to override the extension registry by placing our
-	// default registry first.
-	options = append([]CompileOption{WithExtensionsFromFiles(files)}, options...)
-	return CompileMessageDescriptor(msgDesc, options...), nil
+	return CompileProtoRegistryFiles(files, messageName, options...)
 }
 
 // CompileMessageDescriptor compiles a descriptor into a [MessageType], for optimized parsing.
@@ -68,6 +56,23 @@ func CompileMessageDescriptor(md protoreflect.MessageDescriptor, options ...Comp
 	return wrapType(ty)
 }
 
+// CompileProtoRegistryFiles look's up a message with the given name using the supplied protobuf file registry, and compiles a type for it.
+func CompileProtoRegistryFiles(files *protoregistry.Files, messageName protoreflect.FullName, options ...CompileOption) (*MessageType, error) {
+	desc, err := files.FindDescriptorByName(messageName)
+	if err != nil {
+		return nil, err
+	}
+	msgDesc, ok := desc.(protoreflect.MessageDescriptor)
+	if !ok {
+		return nil, protoregistry.NotFound
+	}
+
+	// Allow the caller to override the extension registry by placing our
+	// default registry first.
+	options = append([]CompileOption{WithExtensionsFromFiles(files)}, options...)
+	return CompileMessageDescriptor(msgDesc, options...), nil
+}
+
 // backend implements the compiler backend interface.
 type backend struct{}
 

From c7ce1984216c03b00e19519ec5fcccc682540151 Mon Sep 17 00:00:00 2001
From: "marco.ferrer" <marco.ferrer@reddit.com>
Date: Fri, 10 Oct 2025 11:30:50 -0400
Subject: [PATCH 2/2] address PR feedback

---
 compile.go | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/compile.go b/compile.go
index ce13d9e..5dadaab 100644
--- a/compile.go
+++ b/compile.go
@@ -33,7 +33,7 @@ func CompileFileDescriptorSet(fds *descriptorpb.FileDescriptorSet, messageName p
 	if err != nil {
 		return nil, err
 	}
-	return CompileProtoRegistryFiles(files, messageName, options...)
+	return CompileFileRegistry(files, messageName, options...)
 }
 
 // CompileMessageDescriptor compiles a descriptor into a [MessageType], for optimized parsing.
@@ -56,8 +56,11 @@ func CompileMessageDescriptor(md protoreflect.MessageDescriptor, options ...Comp
 	return wrapType(ty)
 }
 
-// CompileProtoRegistryFiles look's up a message with the given name using the supplied protobuf file registry, and compiles a type for it.
-func CompileProtoRegistryFiles(files *protoregistry.Files, messageName protoreflect.FullName, options ...CompileOption) (*MessageType, error) {
+// CompileFileRegistry looks up a [protoreflect.MessageDescriptor] from a [protoregistry.Files] and
+// compiles a [MessageType] for it.
+//
+// Returns an error if no message type exists in the registry with that name.
+func CompileFileRegistry(files *protoregistry.Files, messageName protoreflect.FullName, options ...CompileOption) (*MessageType, error) {
 	desc, err := files.FindDescriptorByName(messageName)
 	if err != nil {
 		return nil, err