feat: Enhance error message consistency and descriptiveness by adding default backend error messages and updating frontend error titles.

Author: Junyi-99

internal/api/actor.go

@@ -3,12 +3,12 @@ package api
 import (
 	"context"
 
+	"go.mongodb.org/mongo-driver/v2/bson"
+
 	"paperdebugger/internal/accesscontrol"
 	"paperdebugger/internal/libs/jwt"
 	"paperdebugger/internal/libs/shared"
 	"paperdebugger/internal/services"
-
-	"go.mongodb.org/mongo-driver/v2/bson"
 )
 
 func parseUserActor(ctx context.Context, token string, userService *services.UserService) (*accesscontrol.Actor, error) {

internal/libs/shared/error.go

@@ -76,6 +76,13 @@ func makeErrorFunc(
 		detail := lo.FirstOrEmpty(details)
 		var errorMessage string
 		switch v := detail.(type) {
+		case nil:
+			// Use default message from errorCodeMessages when no details provided
+			if msg, ok := errorCodeMessages[errorCode]; ok {
+				errorMessage = msg
+			} else {
+				errorMessage = "An error occurred"
+			}
 		case error:
 			errorMessage = v.Error()
 		case interface{ String() string }:

webapp/_webapp/src/libs/apiclient.ts

@@ -144,20 +144,21 @@ class ApiClient {
     return msg;
   }
 
+  // Error titles aligned with backend errorCodeMessages (error.go) for consistency
   private getErrorTitle(code: ErrorCode): string {
     const titles: Record<ErrorCode, string> = {
-      [ErrorCode.UNSPECIFIED]: "Unspecified Error",
-      [ErrorCode.UNKNOWN]: "Unknown Error",
-      [ErrorCode.INVALID_TOKEN]: "Authentication Required",
-      [ErrorCode.INVALID_ACTOR]: "Session Invalid",
-      [ErrorCode.INVALID_USER]: "User Not Found",
-      [ErrorCode.PERMISSION_DENIED]: "Access Denied",
-      [ErrorCode.RECORD_NOT_FOUND]: "Not Found",
-      [ErrorCode.BAD_REQUEST]: "Invalid Request",
-      [ErrorCode.INTERNAL]: "Server Error",
-      [ErrorCode.INVALID_CREDENTIAL]: "Invalid Credentials",
-      [ErrorCode.INVALID_LLM_RESPONSE]: "AI Response Error",
-      [ErrorCode.PROJECT_OUT_OF_DATE]: "Project Outdated",
+      [ErrorCode.UNSPECIFIED]: "An unspecified error occurred",
+      [ErrorCode.UNKNOWN]: "An unknown error occurred",
+      [ErrorCode.INVALID_TOKEN]: "Invalid or missing authentication token",
+      [ErrorCode.INVALID_ACTOR]: "Invalid actor or session",
+      [ErrorCode.INVALID_USER]: "User not found or invalid",
+      [ErrorCode.PERMISSION_DENIED]: "Permission denied",
+      [ErrorCode.RECORD_NOT_FOUND]: "Record not found",
+      [ErrorCode.BAD_REQUEST]: "Bad request",
+      [ErrorCode.INTERNAL]: "Internal server error",
+      [ErrorCode.INVALID_CREDENTIAL]: "Invalid credentials",
+      [ErrorCode.INVALID_LLM_RESPONSE]: "Invalid LLM response",
+      [ErrorCode.PROJECT_OUT_OF_DATE]: "Project is out of date",
     };
     return titles[code] || "Request Failed";
   }