chore: mock server name validation and prevent duplicates (hoppscotch#5524)

Author: mirarifhasan

packages/hoppscotch-backend/src/mock-server/mock-server.model.ts

@@ -7,15 +7,22 @@ import {
   registerEnumType,
 } from '@nestjs/graphql';
 import {
-  IsAlphanumeric,
   IsNumber,
   IsOptional,
+  IsString,
+  Matches,
   Max,
   MaxLength,
   MinLength,
 } from 'class-validator';
 import { WorkspaceType } from 'src/types/WorkspaceTypes';
 
+// Regex pattern for mock server name validation
+// Allows letters, numbers, spaces, dots, underscores, and hyphens
+const MOCK_SERVER_NAME_PATTERN = /^[a-zA-Z0-9 ._-]+$/;
+const MOCK_SERVER_NAME_ERROR_MESSAGE =
+  'Name can only contain letters, numbers, spaces, dots, underscores, and hyphens';
+
 @ObjectType()
 export class MockServer {
   @Field(() => ID, {
@@ -102,9 +109,12 @@ export class CreateMockServerInput {
   @Field({
     description: 'Name of the mock server',
   })
+  @IsString()
   @MinLength(1)
   @MaxLength(255)
-  @IsAlphanumeric()
+  @Matches(MOCK_SERVER_NAME_PATTERN, {
+    message: MOCK_SERVER_NAME_ERROR_MESSAGE,
+  })
   name: string;
 
   @Field({
@@ -149,10 +159,13 @@ export class UpdateMockServerInput {
     nullable: true,
     description: 'Name of the mock server',
   })
+  @IsString()
   @IsOptional()
   @MinLength(1)
   @MaxLength(255)
-  @IsAlphanumeric()
+  @Matches(MOCK_SERVER_NAME_PATTERN, {
+    message: MOCK_SERVER_NAME_ERROR_MESSAGE,
+  })
   name?: string;
 
   @Field({