type-graphql Cannot find module 'class-validator' exception

Question

I am trying to create a GQL mutation by TypeORM and using SQL Server as database. If I am trying to run the mutation it is throwing exception. Sharing the code below;

index.ts

(async () => {
    const app = express();
    
        await createConnection();
    
        const apolloServer = new ApolloServer({
            schema: await buildSchema({
                resolvers: [UserRegistrationResolver, HealthResolver],
            }),
            tracing: true,
            context: ({ req, res }) => ({ req, res })
        });
    
        apolloServer.applyMiddleware({ app, cors: false });
    
        app.listen(4000, () => {
            console.log("App is started");
        })
     })();

GQL Types:

@InputType()
export class UserRegistrationType {

      /*......*/
      @Field()
      Reg_Security_Qus_Ans: string;
     /*......*/

}

Entity:

@ObjectType()
@Entity()
export class User_Registration extends BaseEntity {

          /*......*/

    @Field(() => Int)
    @OneToOne(()=> Security_Questions)
    @JoinColumn()
    Reg_Security_Qus_ID: Security_Questions;

         /*......*/
}

Mutation:

@Resolver()
export class UserRegistrationResolver {
@Mutation(() => User_Registration)
     async createRegistrations(
                @Arg("RegistrationMutation") registrationMutation: UserRegistrationType
          ) {
                console.log("Boom1");
                let oneUser = await User_Registration.insert(registrationMutation);
                return oneUser; 
          }
    
          @Query(() => User_Registration)
          getUsers() {
                console.log("Boom");
                return User_Registration.find();
          } 
}

When, I am trying to execute the mutation some weird error is appearing like below, asking me for 'class-validator', the error looks something like this,

"message": "Cannot find module 'class-validator'\nRequire stack:\n- 

Can anyone help me to solve this. I am stuck with this. Thanks in advance.

Answer 1

I was stupid, I had to install

npm i class-validator

this package. thats all