feat: Custom Length decorator for UTF-8 chars len (#3709)

* feat: Custom Length decorator for UTF-8 chars len

* fix: Length decorator function return type

server/models/Document.ts

@@ -17,7 +17,6 @@ import {
   BelongsTo,
   Column,
   Default,
-  Length,
   PrimaryKey,
   Table,
   BeforeValidate,
@@ -51,6 +50,7 @@ import User from "./User";
 import View from "./View";
 import ParanoidModel from "./base/ParanoidModel";
 import Fix from "./decorators/Fix";
+import { Length } from "./decorators/Length";
 
 export type SearchResponse = {
   results: {

server/models/decorators/Length.ts

@@ -0,0 +1,27 @@
+import { size } from "lodash";
+import { addAttributeOptions } from "sequelize-typescript";
+
+/**
+ * A decorator that calculates size of the string based on lodash's size function.
+ * particularly useful for strings with unicode characters of variable lengths.
+ */
+export function Length({
+  msg,
+  min,
+  max,
+}: {
+  msg?: string;
+  min: number;
+  max: number;
+}): (target: any, propertyName: string) => void {
+  return (target: any, propertyName: string) =>
+    addAttributeOptions(target, propertyName, {
+      validate: {
+        validLength(value: string) {
+          if (size(value) > max || size(value) < min) {
+            throw new Error(msg);
+          }
+        },
+      },
+    });
+}