feat: ✨ Add validation decorators，class-validator to DTO

libs/users/interface-adapters/src/lib/dto/user.dto.spec.ts

@@ -13,4 +13,48 @@ describe('UserDto', () => {
     expect(userDto.email).toBe(email);
     expect(userDto.firstName).toBe(firstName);
   });
+
+  it('should handle empty firstName and lastName', () => {
+    const id = '456';
+    const email = '[email protected]';
+    const userDto = new UserDto(id, email, null, null);
+
+    expect(userDto).toBeDefined();
+    expect(userDto.id).toBe(id);
+    expect(userDto.email).toBe(email);
+    expect(userDto.firstName).toBeUndefined();
+    expect(userDto.lastName).toBeUndefined();
+  });
+
+  it('should validate email format', () => {
+    const id = '789';
+    const invalidEmail = 'invalid-email';
+
+    expect(() => {
+      new UserDto(id, invalidEmail, null, null);
+    }).toThrow();
+  });
+
+  it('should require id and email', () => {
+    expect(() => {
+      // @ts-expect-error testing invalid constructor args
+      new UserDto();
+    }).toThrow();
+
+    expect(() => {
+      // @ts-expect-error testing invalid constructor args
+      new UserDto('123');
+    }).toThrow();
+  });
+
+  it('should handle special characters in names', () => {
+    const id = '101';
+    const email = '[email protected]';
+    const firstName = 'Jean-Pierre';
+    const lastName = "O'Connor";
+    const userDto = new UserDto(id, email, firstName, lastName);
+
+    expect(userDto.firstName).toBe(firstName);
+    expect(userDto.lastName).toBe(lastName);
+  });
 });

libs/users/interface-adapters/src/lib/dto/user.dto.ts

@@ -1,3 +1,4 @@
+import { IsEmail, IsString } from 'class-validator';
 import { Field, ID, ObjectType } from '@nestjs/graphql';
 
 @ObjectType()
@@ -6,12 +7,15 @@ export class UserDto {
   id: string;
 
   @Field()
+  @IsEmail()
   email: string;
 
   @Field()
-  firstName: string | null;
+  @IsString()
+  firstName?: string | null;
 
   @Field()
+  @IsString()
   lastName: string | null;
 
   constructor(