feat: add option for disabling generation of top level resources

Author: ericwenn

README.md

@@ -39,6 +39,10 @@ filename                Name of the file to generate the code to.
 insertion_point         If non-empty, indicates that the named file should already exist,
                         and the content here is to be inserted into that file at a defined 
                         insertion point. 
+
+skip_file_resource_definitions
+                        If set to true, resource names will not be generated for resource definitions
+                        in the file scope. Default: false.
 ```
 
 ---

internal/plugin/generate.go

@@ -42,6 +42,9 @@ func Generate(request *pluginpb.CodeGeneratorRequest) (*pluginpb.CodeGeneratorRe
 		if _, ok := generate[descriptor.ParentFile]; !ok {
 			return true
 		}
+		if opts.SkipFileResourceDefinitions && !isMessageResourceDescriptor(descriptor) {
+			return true
+		}
 		dir := path.Dir(descriptor.ParentFile)
 		packageResources[dir] = append(packageResources[dir], descriptor)
 		return true
@@ -67,3 +70,7 @@ func Generate(request *pluginpb.CodeGeneratorRequest) (*pluginpb.CodeGeneratorRe
 
 	return &response, nil
 }
+
+func isMessageResourceDescriptor(r *aipreflect.ResourceDescriptor) bool {
+	return r.Message != ""
+}

internal/plugin/options.go

@@ -14,6 +14,11 @@ type Options struct {
 	// use.
 	// Defaults to `""` (ie. no insertion point)
 	InsertionPoint string
+
+	// SkipFileResourceDefinitions disables generation of resource names
+	// declared in the file scope.
+	// Defaults to false.
+	SkipFileResourceDefinitions bool
 }
 
 func defaultOptions() Options {
@@ -46,9 +51,25 @@ func (o *Options) Unmarshal(s *string) error {
 			o.InsertionPoint = value
 		case "filename":
 			o.Filename = value
+		case "skip_file_resource_definitions":
+			b, err := unmarshalBool(value)
+			if err != nil {
+				return fmt.Errorf("unmarshal skip_file_resource_definitions: %w", err)
+			}
+			o.SkipFileResourceDefinitions = b
 		default:
 			return fmt.Errorf("unknown option [%s]", opt)
 		}
 	}
 	return nil
 }
+
+func unmarshalBool(s string) (bool, error) {
+	switch s {
+	case "false":
+		return false, nil
+	case "true":
+		return true, nil
+	}
+	return false, fmt.Errorf("invalid bool value '%s', expected one of 'true' or 'false'", s)
+}