This type does not possess the designated property

Question

This type does not possess the designated property

I've encountered a puzzling issue with my code. It seems that the authenticateUser function returns an array structured like this:

{
  success: false,
  msg: "invalid password"
}

However, when I attempt to verify if success == false, I receive an error stating that there is no such property on type Objects.

this.authService.authenticateUser(user).subscribe(data=>{
  if(data.success){//here need to check response for success
    console.log(data)
    this.authService.storeUserData(data);
    this.router.navigate(['/user']);
  }else{
    this.router.navigate(['/login']);
  }

Despite reviewing examples from various tutorials, I have yet to find a solution to this problem.

angular typescript

Answer 1

Answer №1

There are two different approaches to accomplish this task:

First, you can opt to utilize the type any:

this.authService.authenticateUser(user).subscribe((data: any)=>{
  if(data.success){//it is important to verify if the response indicates success
    console.log(data)
    this.authService.storeUserData(data);
    this.router.navigate(['/user']);
  }else{
    this.router.navigate(['/login']);
  }
}

Alternatively, you can define a strongly typed structure like {success: boolean, msg: string} or create an interface for this purpose:

this.authService.authenticateUser(user).subscribe((data: {success: boolean, msg: string}) =>{
  if(data.success){//ensure to validate the response for success
    console.log(data)
    this.authService.storeUserData(data);
    this.router.navigate(['/user']);
  }else{
    this.router.navigate(['/login']);
  }
}

Answer 2

There are two different approaches to accomplish this task:

First, you can opt to utilize the type any:

this.authService.authenticateUser(user).subscribe((data: any)=>{
  if(data.success){//it is important to verify if the response indicates success
    console.log(data)
    this.authService.storeUserData(data);
    this.router.navigate(['/user']);
  }else{
    this.router.navigate(['/login']);
  }
}

Alternatively, you can define a strongly typed structure like {success: boolean, msg: string} or create an interface for this purpose:

this.authService.authenticateUser(user).subscribe((data: {success: boolean, msg: string}) =>{
  if(data.success){//ensure to validate the response for success
    console.log(data)
    this.authService.storeUserData(data);
    this.router.navigate(['/user']);
  }else{
    this.router.navigate(['/login']);
  }
}

Answer 3

Answer №2

I may not have much experience with Angular, but from what I understand, the issue here seems to be related to improper typing of data. One way you could potentially solve this problem is by using casting or a type-guard.

const checkSuccess = (input: any): input is {success: boolean} {
     return "success" in input;
}

if(checkSuccess(data) && data.success) ...

Answer 4

I may not have much experience with Angular, but from what I understand, the issue here seems to be related to improper typing of data. One way you could potentially solve this problem is by using casting or a type-guard.

const checkSuccess = (input: any): input is {success: boolean} {
     return "success" in input;
}

if(checkSuccess(data) && data.success) ...

This type does not possess the designated property

Answer №1

Answer №2

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