Access a repo in a guard in nestjs - nestjs

Before upgrading to typeorm 0.3 I could use getConnection().getRepository<User>(User) in my guard to get a repo for a type and operate on it.
With 0.3 however that is deprecated (see also https://newreleases.io/project/github/typeorm/typeorm/release/0.3.0) and now I cannot get access to the db in my guard anymore. I tried to use
#InjectRepository(User)
private userRepo: Repository<User>,
in the guard's constructor and then tried to make the guard a provider from a module that I exported but also that didnt work.
So I wonder how to get access to a repo or connection there. Otherwise I would probably need to pass my connection details to the Guard and create a new connecion ther which seems aweful.

You can try with mixin https://wanago.io/2021/12/13/api-nestjs-mixin-pattern/.
Check the section Passing additional arguments.
I have done it with DataSource you can use Repository as well.
//scope.guard.ts
import { CanActivate, ExecutionContext, NotFoundException, Inject, Type, mixin } from "#nestjs/common";
import { DataSource, getRepository, ObjectType } from "typeorm";
import { Request } from "express";
const ScopeGuard = (entityClass): Type<CanActivate> => {
class ScopeGuardMixin {
constructor(#Inject(DataSource) private readonly dataSource: DataSource) {}
async canActivate(context: ExecutionContext): Promise<boolean> {
console.log("here 1");
console.log(entityClass);
console.log("here 2");
const request = context.switchToHttp().getRequest<Request>();
console.log(await this.dataSource.getRepository(entityClass).findOneBy({ id: Number(request.params.id) }));
return true;
}
}
return mixin(ScopeGuardMixin);
};
export default ScopeGuard;
Controller code
import ScopeGuard from "app/modules/guards/scope.guard";
#UseGuards(ScopeGuard(User))

Related

NestJs - Validate request body using class-validator having 2 options for body class

I have a rest call, which might receive body of type classA or classB.
I need to keep it as 2 different classes.
Example -
// classes -
class ClassA {
#IsString()
#Length(1, 128)
public readonly name: string;
#IsString()
#Length(1, 128)
public readonly address: string;
}
class ClassB {
#IsString()
#Length(1, 10)
public readonly id: string;
}
// my request controller -
#Post('/somecall')
public async doSomething(
#Body(new ValidationPipe({transform: true})) bodyDto: (ClassA | ClassB) // < not validating any of them..
): Promise<any> {
// do something
}
The issue is, that when having more than one class, body is not validated.
How can I use 2 or more classes and validate them using class-validator?
I don't want to use same class..
Thank you all :)
I don't want to use same class..
Then it won't be possible, at least not with Nest's built-in ValidationPipe. Typescript doesn't reflect unions, intersections, or other kinds of generic types, so there's no returned metadata for this parameter, and if there's no metadata that's actionable Nest will end up skipping the pipe.
You could probably create a custom pipe to do the validation for you, and if you have two types you're probably going to have to. You can still call the appropriate class-transformer and class-validator methods inside of the class too.
import { CallHandler, ExecutionContext, Injectable, NestInterceptor } from '#nestjs/common';
import { of } from 'rxjs';
#Injectable()
export class CheckTypeInterceptor implements NestInterceptor {
constructor() {}
async intercept(context: ExecutionContext, next: CallHandler) /*: Observable<any>*/ {
const httpContext = context.switchToHttp();
const req = httpContext.getRequest();
const bodyDto = req.body.bodyDto;
// Need Update below logic
if (bodyDto instanceof ClassA || bodyDto instanceof ClassB) {
return next.handle();
}
// Return empty set
return of([]);
}
}
#UseInterceptors(CheckTypeInterceptor)
export class ApiController {
...
}
Encountered a similar situation where I had to validate some union type request. The solution I ended up with was a custom pipe as Jay McDoniel suggested here. The logic would vary depending on the request body you are dealing with, but per the question in case the following may work
Custom pipe:
import { ArgumentMetadata, BadRequestException, Inject, Scope } from "#nestjs/common";
import { PipeTransform } from "#nestjs/common";
import { plainToInstance } from "class-transformer";
import { validate } from "class-validator";
import { ClassADto } from '../repository/data-objects/class-a.dto';
import { ClassBDto } from '../repository/data-objects/class-b.dto';
export class CustomPipeName implements PipeTransform<any> {
async transform(value: any, { metatype, type }: ArgumentMetadata): Promise<any> {
if (type === 'body') {
const classA = plainToInstance(ClassADto, value);
const classB = plainToInstance(ClassBDto, value);
const classAValidationErrors = await validate(classA);
const classBValidationErrors = await validate(classB);
if (classAValidationErrors.length > 0 && classBValidationErrors.length > 0) {
throw new BadRequestException('some fancy info text');
}
}
return value;
}
}
Controller usage:
#Post('/somecall')
public async doSomething(
#Body(new CustomePipeName()) bodyDto: (ClassA | ClassB)
): Promise<any> {
// do something
}

How to get repository in NestJS Interceptor

I had created on Interceptor in the module. I want to get repository [LocumRepository] in the Interceptor and put some processing after the call.
Following is my Intercepter class:
import { CallHandler, ExecutionContext, Injectable, NestInterceptor } from '#nestjs/common';
import { LocumEntity } from '../../locum/entities/locum.entity';
import { getRepository, Like, Repository } from 'typeorm';
import { Observable, combineLatest } from 'rxjs';
import { tap } from 'rxjs/operators';
import { map } from 'rxjs/operators';
#Injectable()
export class ApprovalInterceptor implements NestInterceptor {
intercept(context: ExecutionContext, next: CallHandler): Observable<any> {
return next
.handle()
.pipe(
map(value => this.updateLocumStatus(value, context))
);
}
async updateLocumStatus(value, context) {
if (context.switchToHttp().getResponse().statusCode) {
let locumData = await getRepository(LocumEntity)
.createQueryBuilder('locum')
.where('locum.id = :id', { id: value.locumId })
.getOne();
}
return value;
}
}
I am receiving following error:
No repository for "LocumRepository" was found. Looks like this entity is not registered in current "default" connection?
while LocumRepository declared in the module file and I am using it out side the Interceptor class
As an interceptor is #Injectable() you could take the DI approach and inject it as you normally would using #InjectRepository(Locum) (or whatever your entity is called), and then do the usual service this.repo.repoMethod(). This way, you also still get the benefits of using DI and being able to provide amock during testing. The only thing to make sure of with this approach is that you have this repository available in the current module where the interceptor will be used.

How to ignore some routes from #UseGuards() in a controller?

I have a controller like this:
#ApiBearerAuth()
#UseGuards(AuthGuard('jwt'))
#ApiTags('books')
#Controller('books')
export class BooksController {
#Post()
async create(#Body() createBookVm: CreateBookVm) {
//........
}
#Get()
async all() {
//........
}
}
When I access all() rout in above controller without accessToken I get the foloowing error:
{"statusCode":401,"error":"Unauthorized"}
It is a correct behavior but I want ignore all() action from general #UseGuards of the controller. I want access it as a public rout without authorization.
The easiest way is to change Guards to routes:
#ApiBearerAuth()
#ApiTags('books')
#Controller('books')
export class BooksController {
#Post()
#UseGuards(AuthGuard('jwt'))
async create(#Body() createBookVm: CreateBookVm) {
//........
}
#Get()
async all() {
//........
}
}
To provide another answer, albeit one that requires more code, is you could create a custom decorator that assigns metadata to the class and/or the class method. This metadata, in theory, would be for telling the guard to skip the auth check on this entire class, or on this route (depending on how you set the metadata up), and return true so that the request can still flow.
I've got a decorator like this set up here that sets up metadata if you'd like to take a look at how it works.
With this kind of approach, you could bind the guard globally, and then add the #AuthSkip() (or whatever you call it) decorator to the routes or classes you don't want to authorize.
Now you'll need to extend the AuthGuard('jwt') and update the canActivate() method to check for this metadata in the current context. This means that you'll need to add the Reflector as a dependency to the guard class and use it to get the metadata from both the class and the current route (if you went so far as to make it work for ignoring classes and not just routes), and if the metadata exists, then the route was to be skipped, return true from the guard. I make that kind of check here if you'd like to see an example of that in action.
Assuming you have used the app.useGlobalGuards() method inside main.ts file, add the following code inside the auth.guard.ts file:
import { ExecutionContext, Injectable } from '#nestjs/common';
import { Reflector } from '#nestjs/core';
import { AuthGuard as PassportAuthGaurd } from '#nestjs/passport';
#Injectable()
export class AuthGuard extends PassportAuthGaurd('jwt') {
constructor(private readonly reflector: Reflector) {
super();
}
canActivate(context: ExecutionContext) {
const isPublic = this.reflector.get<boolean>(
'isPublic',
context.getHandler()
);
if (isPublic) {
return true;
}
return super.canActivate(context);
}
}
I had used pssport jwt method here, but you can alter it according to you, just remember to keep constructor and the logic of canActivate same.
Now in your main.ts modify global guard so we can use Reflectors in it:
const reflector = app.get(Reflector);
app.useGlobalGuards(new AuthGuard(reflector));
Now in order to make routes public we would use a custom decorator, for that create a file named public.decorator.ts and add the following code:
import { SetMetadata } from '#nestjs/common';
export const Public = () => SetMetadata('isPublic', true);
Here we have added a custom metadata value which is same value that we used inside our auth.guard.ts file. Now just add this #Public() decorator on the route that you want to make public:
#Get()
#Public()
async all() {
//........
}
Now your all function won't check for the token authentication.
I found this blog which does the same thing, you can check it out.

Is it possible to override global scoped guard with controller/method scoped one

I'm writing webAPI using NestJS framework. I was not able to override global scoped guard with the one placed on method or controller level. All of my endpoints will use JWT verification guard except one used for logging into the system. Is it possible to create one guard on root level and only override this global guard with #UseGuard() decorator on single method level?
I tried to use guard before listen function call and also use APP_GUARDprovider, but in both cases I'm not able to override this behavior.
Code example:
https://codesandbox.io/embed/nest-yymkf
Just to add my 2 cents.
Instead of defining 2 guards (reject and accept) as the OP have done, I have defined a custom decorator:
import { SetMetadata } from '#nestjs/common'
export const NoAuth = () => SetMetadata('no-auth', true)
The reject guard (AuthGuard) uses Reflector to be able to access the decorator's metadata and decides to activate or not based on it.
import { CanActivate, ExecutionContext, Injectable } from '#nestjs/common'
import { Reflector } from '#nestjs/core'
import { Observable } from 'rxjs'
#Injectable()
export class AuthGuard implements CanActivate {
constructor(private readonly reflector: Reflector) {}
canActivate(
context: ExecutionContext,
): boolean | Promise<boolean> | Observable<boolean> {
const noAuth = this.reflector.get<boolean>('no-auth', context.getHandler())
if(noAuth) return true
// else your logic here
}
}
I then bind the reject guard globally in some module:
#Module({
providers: [{
provide: APP_GUARD,
useClass: AuthGuard
}]
})
and proceed to use the decorator where needed:
#NoAuth()
#Get() // anyone can access this
getHello(): string {
return 'Hello Stranger!'
}
#Get('secret') // protected by the global guard
getSecret(): string {
return 'ssshhh!'
}
After a posting the question I figured out the solution for my problem. I should add some custom meta-data into my controller and put a logic inside the guard to read that meta-data.
I have updated the code sample.

Access Nest "injector" in a custom interceptor

I need to access a service (provided by Nest TypeOrmModule) inside the intercept function (important note: not as constructor parameter!!!) because it depends of the passed options (entity in this case).
The service injection token is provided by the getRepositoryToken function.
export class PaginationInterceptor {
constructor(private readonly entity: Function) {}
intercept(context: ExecutionContext, call$: Observable<any>): Observable<any> {
// Here I want to inject the TypeORM repository.
// I know how to get the injection token, but not HOW to
// get the "injector" itself.
const repository = getRepositoryToken(this.entity);
// stuff...
return call$;
}
}
Is any concept of "service container" in Nest? This github issue didn't help me.
Example usage (controller action):
#Get()
#UseInterceptors(new PaginationInterceptor(Customer))
async getAll() {
// stuff...
}
Regarding dependency injection (if you really want/need it), I guess using a mixin class can do the trick. See the v4 documentation (Advanced > Mixin classes).
import { NestInterceptor, ExecutionContext, mixin, Inject } from '#nestjs/common';
import { getRepositoryToken } from '#nestjs/typeorm';
import { Observable } from 'rxjs';
import { Repository } from 'typeorm';
export function mixinPaginationInterceptor<T extends new (...args: any[]) => any>(entityClass: T) {
// declare the class here as we can't give it "as-is" to `mixin` because of the decorator in its constructor
class PaginationInterceptor implements NestInterceptor {
constructor(#Inject(getRepositoryToken(entityClass)) private readonly repository: Repository<T>) {}
intercept(context: ExecutionContext, $call: Observable<any>) {
// do your things with `this.repository`
return $call;
}
}
return mixin(PaginationInterceptor);
}
Disclaimer: this is valid TypeScript code but I didn't had the chance to test it in a real project, so it might need a bit of rework. The idea is to use it like this:
#UseInterceptors(mixinPaginationInterceptor(YourEntityClass))
Let me know if you have any question about the code. But I think the doc about mixin is pretty good!
OR You can also use getRepository from typeorm (passing the entity class). This is not DI, thus, it will oblige you to spyOn the getRepository function in order to do proper testing.
Regarding the container, I'm almost sure that the only way to access it is using the Execution Context, as pointed by Kim.

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