fix: handle nullable properly

scripts/jsonrpc_typings/schema.go

@@ -174,6 +174,11 @@ func extractMapType(t reflect.Type, schema *APISchema) *APIType {
 
 // extractStructType handles struct types
 func extractStructType(t reflect.Type, schema *APISchema) *APIType {
+	// Skip null.* structs as they are handled as optional properties
+	if strings.HasPrefix(t.String(), "null.") {
+		return nil
+	}
+
 	apiType := &APIType{
 		Name:   t.String(),
 		Kind:   TypeKindStruct,
@@ -186,6 +191,9 @@ func extractStructType(t reflect.Type, schema *APISchema) *APIType {
 	}
 
 	// Extract fields
+	embeddedStructs := make([]string, 0)
+	regularFields := make([]APIField, 0)
+
 	for i := 0; i < t.NumField(); i++ {
 		field := t.Field(i)
 
@@ -194,17 +202,36 @@ func extractStructType(t reflect.Type, schema *APISchema) *APIType {
 			continue
 		}
 
-		apiField := buildAPIField(field)
+		// Check if this is an embedded struct (anonymous field)
-		apiType.Fields = append(apiType.Fields, apiField)
+		if field.Anonymous && field.Type.Kind() == reflect.Struct {
+			embeddedStructs = append(embeddedStructs, field.Type.String())
+			// Recursively extract nested struct types from embedded structs
+			if nestedType := extractAPIType(field.Type, schema); nestedType != nil {
+				if nestedType.Kind == TypeKindStruct {
+					schema.Types[nestedType.Name] = *nestedType
+				}
+			}
+		} else {
+			apiField := buildAPIField(field)
+			regularFields = append(regularFields, apiField)
 
-		// Recursively extract nested struct types from field types
+			// Recursively extract nested struct types from field types
-		if nestedType := extractAPIType(field.Type, schema); nestedType != nil {
+			if nestedType := extractAPIType(field.Type, schema); nestedType != nil {
-			if nestedType.Kind == TypeKindStruct {
+				if nestedType.Kind == TypeKindStruct {
-				schema.Types[nestedType.Name] = *nestedType
+					schema.Types[nestedType.Name] = *nestedType
+				}
 			}
 		}
 	}
 
+	// If we have exactly one embedded struct and no regular fields, mark it as an extension
+	if len(embeddedStructs) == 1 && len(regularFields) == 0 {
+		apiType.Kind = TypeKindExtension
+		apiType.Extends = embeddedStructs[0]
+	} else {
+		apiType.Fields = regularFields
+	}
+
 	return apiType
 }
 
@@ -310,7 +337,7 @@ func getAllReferencedStructs(schema *APISchema) []APIType {
 
 	// Also add all structs from the complete schema that might be referenced
 	for name, apiType := range schema.Types {
-		if apiType.Kind == TypeKindStruct {
+		if apiType.Kind == TypeKindStruct || apiType.Kind == TypeKindExtension {
 			allStructs[name] = apiType
 		}
 	}

scripts/jsonrpc_typings/types.go

@@ -18,6 +18,8 @@ const (
 	TypeKindArray TypeKind = "array"
 	// TypeKindPointer represents a pointer type
 	TypeKindPointer TypeKind = "pointer"
+	// TypeKindExtension represents a struct that extends another struct
+	TypeKindExtension TypeKind = "extension"
 )
 
 // APIType represents a type used in the JSON-RPC API
@@ -26,6 +28,7 @@ type APIType struct {
 	Package      string     `json:"package"`
 	Kind         TypeKind   `json:"kind"`
 	Fields       []APIField `json:"fields,omitempty"`
+	Extends      string     `json:"extends,omitempty"`
 	IsPointer    bool       `json:"is_pointer"`
 	IsSlice      bool       `json:"is_slice"`
 	IsMap        bool       `json:"is_map"`

scripts/jsonrpc_typings/typescript.go

@@ -24,6 +24,7 @@ func generateTypeScriptTypings(schema *APISchema, searchPath string) string {
 		"sub":                func(a, b int) int { return a - b },
 		"pad":                func(s string, width int) string { return padString(s, width) },
 		"padComment":         func(fieldName, fieldType string) string { return padComment(fieldName, fieldType) },
+		"isOptionalType":     func(goType string) bool { return isOptionalType(goType) },
 	}
 
 	// Parse the main template
@@ -65,6 +66,11 @@ func padComment(fieldName, fieldType string) string {
 	return strings.Repeat(" ", targetColumn-declarationLength)
 }
 
+// isOptionalType determines if a Go type should be rendered as an optional TypeScript property
+func isOptionalType(goType string) bool {
+	return goType == "null.String" || goType == "null.Bool" || goType == "null.Int"
+}
+
 // cleanTypeName cleans up Go type names for TypeScript
 func cleanTypeName(typeName string) string {
 	// Remove package prefixes
@@ -105,6 +111,12 @@ func parseTypeRecursively(goType string) string {
 		return "string"
 	case "usbgadget.ByteSlice":
 		return "number[]"
+	case "null.String":
+		return "string"
+	case "null.Bool":
+		return "boolean"
+	case "null.Int":
+		return "number"
 	case "interface {}":
 		return "any"
 	case "time.Duration":
@@ -237,12 +249,15 @@ func hasParameters(handler APIHandler) bool {
 // typescriptTemplate is the main template for generating TypeScript definitions
 const typescriptTemplate = `// Code generated by generate_typings.go. DO NOT EDIT.
 {{range $struct := getAllStructs}}
+{{if eq $struct.Kind "extension"}}
+export interface {{cleanTypeName $struct.Name}} extends {{cleanTypeName $struct.Extends}} {
+}
+{{else}}
 export interface {{cleanTypeName $struct.Name}} {
-{{range $field := $struct.Fields}}  {{$field.JSONName}}: {{goToTypeScriptType $field.Type}};{{padComment $field.JSONName (goToTypeScriptType $field.Type)}}// {{$field.Name}} {{$field.Type}}
+{{range $field := $struct.Fields}}  {{$field.JSONName}}{{if isOptionalType $field.Type}}?{{end}}: {{goToTypeScriptType $field.Type}};{{padComment $field.JSONName (goToTypeScriptType $field.Type)}}// {{$field.Name}} {{$field.Type}}
 {{end}}}
-
 {{end}}
-
+{{end}}
 // String aliases with constants
 {{range $alias := getStringAliasInfo}}
 export type {{$alias.Name}} = {{range $i, $const := $alias.Constants}}"{{$const}}"{{if lt $i (sub (len $alias.Constants) 1)}} | {{end}}{{end}};
@@ -276,11 +291,6 @@ export interface JsonRpcErrorResponse {
 
 export type JsonRpcResponse = JsonRpcSuccessResponse | JsonRpcErrorResponse;
 
-// Handler method types (generated from actual handlers)
-export type JsonRpcMethod = 
-{{range $i, $method := getSortedMethods}}{{if $i}}  | {{else}}  | {{end}}"{{$method}}"
-{{end}};
-
 // RPC Functions
 export class JsonRpcClient {
   constructor(private send: (method: string, params: unknown, callback?: (resp: JsonRpcResponse) => void) => void) {}