Can not inject dependency in my CustomAuthProvider

[khanorder]

i'm trying initialize AuthProvider as described on readme.

but i can not inject dependency in my CustomAuthProvider

If inject without constructor as described on readme, All injected dependencies are undefined.

@injectable()
export class CustomAuthProvider implements interfaces.AuthProvider {

    @inject(LoggerService.name) private readonly _loggerService!: LoggerService;
    @inject(DBService.name) private readonly _db!: DBService;
    @injectHttpContext private readonly _httpContext!: HttpContext;

    public async getUser(
        req: express.Request,
        res: express.Response,
        next: express.NextFunction
    ): Promise<interfaces.Principal> {
        let user: Auth.User|null = null;
        try {
            user = await this._db.SelectUserInfo(req.session.user.email);
            // this._db is undefined
        } catch (error) {
            this._loggerService.logger.error(error);
            // this._loggerService is undefined too.
        }
        const principal = new Principal(user);
        return principal;
    }

}

And if inject a dependency to CustomAuthProvider on constructor of CustomAuthProvider, error occured on line of initializing InversifyExpressServer.

//customAuthProvider.ts

@injectable()
export class CustomAuthProvider implements interfaces.AuthProvider {

    constructor (
        @inject(LoggerService.name) private readonly _loggerService: LoggerService,
        @inject(DBService.name) private readonly _db: DBService,
        @injectHttpContext private readonly _httpContext: HttpContext
    ) {
    }

    public async getUser(
        req: express.Request,
        res: express.Response,
        next: express.NextFunction
    ): Promise<interfaces.Principal> {
        let user: Auth.User|null = null;
        try {
            user = await this._db.SelectUserInfo(req.session.user.email);
        } catch (error) {
            this._loggerService.logger.error(error);
        }
        const principal = new Principal(user);
        return principal;
    }

}

// app.ts
this.container = new Container();
this.container.bind(LoggerService.name).to(LoggerService);
this.container.bind(DBService.name).to(DBService).inSingletonScope();
this.container.bind(CustomAuthProvider.name).to(CustomAuthProvider).inSingletonScope();

this.server = new InversifyExpressServer(this.container, null, null, null, CustomAuthProvider); // error is occured on this line.
//Argument of type 'typeof CustomAuthProvider' is not assignable to parameter of type 'new () => AuthProvider'.
//Types of construct signatures are incompatible.
//Type 'new (_loggerService: LoggerService, _db: DBService, _httpContext: HttpContext) => CustomAuthProvider' is not assignable to type 'new () => AuthProvider'.ts(2345)

How can i use another dependencies on CustomAuthProvider?

[Seth-Carter]

You can't inject in the constructor because the interface.AuthProvider doesn't allow it.

How you did it in your first example is right, although you don't need the httpContext, since the getUser method receives req, res, and next already.

I suspect there's something wrong with your container configuration. Your logger is most likely a simple class instance without any of its dependencies and should be bound with toConstantValue().

Also, you should use generics with bind methods:
this.container.bind<DBService>(DBService.name).to(DBService).inSingletonScope()

If you don't, Inversify will struggle to resolve your bindings. At least I've had issues in the past when I've tried to leave out the generic.

[hArsh92]

Yet there is no straight forward way to achieve this, but I solved it with a work around. Might not be the correct approach but works 100%

import container from '../di/inversify.config';

@injectable()
export class CustomAuthProvider implements interfaces.AuthProvider {
    private readonly _loggerService: LoggerService;
    private readonly _db: DBService;

    constructor () {
           _loggerService = container.get<LoggerService>(LoggerService.name)
          _db = container.get<DBService>(DBService.name)
    }

    public async getUser(
        req: express.Request,
        res: express.Response,
        next: express.NextFunction
    ): Promise<interfaces.Principal> {
        let user: Auth.User|null = null;
        try {
            user = await this._db.SelectUserInfo(req.session.user.email);
        } catch (error) {
            this._loggerService.logger.error(error);
        }
        const principal = new Principal(user);
        return principal;
    }

}

// src/core/di/inversify.config

import { Container } from 'inversify';

const container = new Container();
export default container;

Hope this helps

Note: I'm not able to inject the httpContext for some reason anywhere in the app, apart from controller (not even middleware).