Update LSP error generation, enum naming, string enums (#2173)

Author: jakebailey

internal/lsp/lsproto/_generate/generate.mts

@@ -306,6 +306,29 @@ function patchAndPreprocessModel() {
 
     // Remove _InitializeParams structure after flattening (it was only needed for inheritance)
     model.structures = model.structures.filter(s => s.name !== "_InitializeParams");
+
+    // Merge LSPErrorCodes into ErrorCodes and remove LSPErrorCodes
+    const errorCodesEnum = model.enumerations.find(e => e.name === "ErrorCodes");
+    const lspErrorCodesEnum = model.enumerations.find(e => e.name === "LSPErrorCodes");
+    if (errorCodesEnum && lspErrorCodesEnum) {
+        // Merge LSPErrorCodes values into ErrorCodes
+        errorCodesEnum.values.push(...lspErrorCodesEnum.values);
+        // Remove LSPErrorCodes from the model
+        model.enumerations = model.enumerations.filter(e => e.name !== "LSPErrorCodes");
+    }
+
+    // Singularize plural enum names (e.g., "ErrorCodes" -> "ErrorCode")
+    for (const enumeration of model.enumerations) {
+        if (enumeration.name.endsWith("Codes")) {
+            enumeration.name = enumeration.name.slice(0, -1); // "Codes" -> "Code"
+        }
+        else if (enumeration.name.endsWith("Modifiers")) {
+            enumeration.name = enumeration.name.slice(0, -1); // "Modifiers" -> "Modifier"
+        }
+        else if (enumeration.name.endsWith("Types")) {
+            enumeration.name = enumeration.name.slice(0, -1); // "Types" -> "Type"
+        }
+    }
 }
 
 patchAndPreprocessModel();
@@ -1051,7 +1074,7 @@ function generateCode() {
             value: String(value.value),
             numericValue: Number(value.value),
             name: value.name,
-            identifier: `${enumeration.name}${value.name}`,
+            identifier: `${enumeration.name}${titleCase(value.name)}`,
             documentation: value.documentation,
             deprecated: value.deprecated,
         }));
@@ -1264,6 +1287,14 @@ function generateCode() {
                 }
             }
         }
+
+        // Generate Error() method for ErrorCode to implement the error interface
+        if (enumeration.name === "ErrorCode") {
+            writeLine(`func (e ${enumeration.name}) Error() string {`);
+            writeLine(`\treturn e.String()`);
+            writeLine(`}`);
+            writeLine("");
+        }
     }
 
     const requestsAndNotifications: (Request | Notification)[] = [...model.requests, ...model.notifications];

internal/lsp/lsproto/baseproto.go

@@ -90,51 +90,3 @@ func (w *BaseWriter) Write(data []byte) error {
 	}
 	return w.w.Flush()
 }
-
-type ErrorCode struct { //nolint:errname
-	Name string
-	Code int32
-}
-
-func (e *ErrorCode) Error() string {
-	return e.Name
-}
-
-var (
-	// Defined by JSON-RPC
-	ErrParseError     = &ErrorCode{"ParseError", -32700}
-	ErrInvalidRequest = &ErrorCode{"InvalidRequest", -32600}
-	ErrMethodNotFound = &ErrorCode{"MethodNotFound", -32601}
-	ErrInvalidParams  = &ErrorCode{"InvalidParams", -32602}
-	ErrInternalError  = &ErrorCode{"InternalError", -32603}
-
-	// Error code indicating that a server received a notification or
-	// request before the server has received the `initialize` request.
-	ErrServerNotInitialized = &ErrorCode{"ServerNotInitialized", -32002}
-	ErrUnknownErrorCode     = &ErrorCode{"UnknownErrorCode", -32001}
-
-	// A request failed but it was syntactically correct, e.g the
-	// method name was known and the parameters were valid. The error
-	// message should contain human readable information about why
-	// the request failed.
-	ErrRequestFailed = &ErrorCode{"RequestFailed", -32803}
-
-	// The server cancelled the request. This error code should
-	// only be used for requests that explicitly support being
-	// server cancellable.
-	ErrServerCancelled = &ErrorCode{"ServerCancelled", -32802}
-
-	// The server detected that the content of a document got
-	// modified outside normal conditions. A server should
-	// NOT send this error code if it detects a content change
-	// in it unprocessed messages. The result even computed
-	// on an older state might still be useful for the client.
-	//
-	// If a client decides that a result is not of any use anymore
-	// the client should cancel the request.
-	ErrContentModified = &ErrorCode{"ContentModified", -32801}
-
-	// The client has canceled a request and a server has detected
-	// the cancel.
-	ErrRequestCancelled = &ErrorCode{"RequestCancelled", -32800}
-)

internal/lsp/lsproto/jsonrpc.go

@@ -111,7 +111,7 @@ func (m *Message) UnmarshalJSON(data []byte) error {
 		Error  *ResponseError `json:"error,omitzero"`
 	}
 	if err := json.Unmarshal(data, &raw); err != nil {
-		return fmt.Errorf("%w: %w", ErrInvalidRequest, err)
+		return fmt.Errorf("%w: %w", ErrorCodeInvalidRequest, err)
 	}
 	if raw.ID != nil && raw.Method == "" {
 		m.Kind = MessageKindResponse
@@ -128,7 +128,7 @@ func (m *Message) UnmarshalJSON(data []byte) error {
 	if len(raw.Params) > 0 {
 		params, err = unmarshalParams(raw.Method, raw.Params)
 		if err != nil {
-			return fmt.Errorf("%w: %w", ErrInvalidRequest, err)
+			return fmt.Errorf("%w: %w", ErrorCodeInvalidRequest, err)
 		}
 	}
 
@@ -173,7 +173,7 @@ func (r *RequestMessage) UnmarshalJSON(data []byte) error {
 		Params  jsontext.Value `json:"params"`
 	}
 	if err := json.Unmarshal(data, &raw); err != nil {
-		return fmt.Errorf("%w: %w", ErrInvalidRequest, err)
+		return fmt.Errorf("%w: %w", ErrorCodeInvalidRequest, err)
 	}
 
 	r.ID = raw.ID
@@ -182,7 +182,7 @@ func (r *RequestMessage) UnmarshalJSON(data []byte) error {
 	var err error
 	r.Params, err = unmarshalParams(raw.Method, raw.Params)
 	if err != nil {
-		return fmt.Errorf("%w: %w", ErrInvalidRequest, err)
+		return fmt.Errorf("%w: %w", ErrorCodeInvalidRequest, err)
 	}
 
 	return nil