Refactor user validation

shared/src/entities/user.entity.ts

@@ -1,20 +1,40 @@
 import { Exclude } from 'class-transformer';
 import {
-  IsArray, IsInt, IsNotEmpty,
+  IsAlphanumeric,
+  IsArray,
+  IsInt,
+  IsNotEmpty,
   IsOptional,
-  IsString
+  IsString,
+  Length
 } from 'class-validator';
 import { Roles } from '../dto/roles.dto';
 
-export class EUser {
+// Match this with user validators in frontend
+// (Not security focused, but it tells the user what is wrong)
+
+export class SimpleUsername {
+  @IsNotEmpty()
+  @IsString()
+  @Length(4, 32)
+  @IsAlphanumeric()
+  username: string;
+}
+
+// This is a simple user object with just the username and unhashed password
+export class SimpleUser extends SimpleUsername {
+  @IsNotEmpty()
+  @IsString()
+  @Length(4, 1024)
+  password: string;
+}
+
+// Actual entity that goes in the db
+export class EUser extends SimpleUsername {
   @IsOptional()
   @IsInt()
   id?: number;
 
-  @IsNotEmpty()
-  @IsString()
-  username: string;
-
   @IsArray()
   @IsString({ each: true })
   roles: Roles;