feat(protocol): Add custom request handling

protocol_3_16/custom.go

@@ -0,0 +1,16 @@
+package protocol
+
+import (
+	"encoding/json"
+
+	"github.com/tliron/glsp"
+)
+
+type CustomRequestHandler struct {
+	Method string
+	Func   CustomRequestFunc
+	// This field should be private however it is used in both versions of the protocol
+	Params json.RawMessage
+}
+
+type CustomRequestFunc func(context *glsp.Context, params json.RawMessage) (any, error)

protocol_3_16/handler.go

@@ -82,6 +82,9 @@ type Handler struct {
 	TextDocumentLinkedEditingRange      TextDocumentLinkedEditingRangeFunc
 	TextDocumentMoniker                 TextDocumentMonikerFunc
 
+	// Custom Request/Notification
+	CustomRequest []CustomRequestHandler
+
 	initialized bool
 	lock        sync.Mutex
 }
@@ -709,11 +712,32 @@ func (self *Handler) Handle(context *glsp.Context) (r any, validMethod bool, val
 				r, err = self.TextDocumentMoniker(context, &params)
 			}
 		}
+
+	default:
+		if self.CustomRequest != nil {
+			if handler, ok := self.FindCustomRequestHandler(context.Method); ok {
+				validMethod = true
+				if err = json.Unmarshal(context.Params, &handler.Params); err == nil {
+					validParams = true
+					r, err = handler.Func(context, handler.Params)
+				}
+			}
+		}
+
 	}
 
 	return
 }
 
+func (self *Handler) FindCustomRequestHandler(method string) (*CustomRequestHandler, bool) {
+	for _, handler := range self.CustomRequest {
+		if handler.Method == method {
+			return &handler, true
+		}
+	}
+	return nil, false
+}
+
 func (self *Handler) IsInitialized() bool {
 	self.lock.Lock()
 	defer self.lock.Unlock()

protocol_3_17/handler.go

@@ -648,10 +648,30 @@ func (self *Handler) Handle(context *glsp.Context) (r any, validMethod bool, val
 				r, err = self.TextDocumentDiagnostic(context, &params)
 			}
 		}
+
+	default:
+		if self.CustomRequest != nil {
+			if handler, ok := self.FindCustomRequestHandler(context.Method); ok {
+				validMethod = true
+				if err = json.Unmarshal(context.Params, &handler.Params); err == nil {
+					validParams = true
+					r, err = handler.Func(context, handler.Params)
+				}
+			}
+		}
+
 	}
 
 	return
+}
 
+func (self *Handler) FindCustomRequestHandler(method string) (*protocol316.CustomRequestHandler, bool) {
+	for _, handler := range self.CustomRequest {
+		if handler.Method == method {
+			return &handler, true
+		}
+	}
+	return nil, false
 }
 
 func (self *Handler) IsInitialized() bool {