I tried to insert an Auth System to the Angular App. (This one.

After finishing everything, I got for this code:

private userCurrentState = new BehaviorSubject<boolean>(this.tokenAuthService.isSignedin());

this error message

Argument of type 'boolean | undefined' is not assignable to parameter of type 'boolean'.

TokenAuthService code

getJwtToken(){
    return localStorage.getItem('auth_token');
}

validateToken(){
 const token = this.getJwtToken();
 if(token){
   const payload = this.payload(token);
   if(payload){
     return Object.values(this.tokenIssuer).indexOf(payload.iss) > -1 ? true : false;
   }
 } else {
    return false;
 }
}

isSignedin() {
    return this.validateToken();
}

And I have no idea why. Anybody here to help? Thanks a lot :)

CodePudding user response：

The call this.tokenAuthService.isSignedin() could possibly return undefined, while the BehaviorSubject is expecting a boolean value.

You could get around this by using a boolean variable, and having the variable check the function call to set itself to true if it's true, or false if false or undefined.

CodePudding user response：

Allow BehaviourSubject to accept undefined data type change

private userCurrentState = new BehaviorSubject<boolean>(this.tokenAuthService.isSignedin());

to

private userCurrentState = new BehaviorSubject<boolean | undefined>(this.tokenAuthService.isSignedin());

Or

Since your isSignedin is depends on validateToken(), mark it return type as boolean

validateToken(): boolean{
     const token = this.getJwtToken();
     if(token){
       const payload = this.payload(token);
       if(payload){
         return Object.values(this.tokenIssuer).indexOf(payload.iss) > -1 ? true : false;
       }
       return false; // you can return false here
     } else {
        return false;
     }
  }