How would you fix this "Promise<any>' provides no match for the signature '(value: any): {} | PromiseLike<{}>" Error

user_7572374 0
Viewed 2854

I am trying to user promises in order to do a synchronous execution.

I have followed the instructions listed in a github forum, with no luck. 

getData2(user: string, guid: string) {
  return new Promise<any>((resolve, reject) => {
    //doing some stuff in here
    resolve();
  });
}

getData1(user: string, guid: string) {
  return new Promise<any>((resolve, reject) => {
    //doing some other stuff in here
    resolve();
  });
}

userCheck(user: string) {
  //checking some array in here
}

userMethod(someArray: any){
  var i: any;
  var length = someArray.length;
  for (i=0; i < length; i++){
    this.getData1(someArray[i], userID).then(
      this.getData2(someArray[i], userID)).then(
          this.userCheck(someArray[i]));
      });
    })}
  }

The idea is that I want to first finish getData1 and then do getData2 and then do userCheck.

When I do it the way I have laid out above I get the error message:

Argument of type 'void' is not assignable to parameter of type '(value: {}) => {} | PromiseLike<{}>'.

After fixing this issue I ran into the fact that the userCheck function is still executing before getData2 finishes. I am not sure why. the getData2 function looks like this. 

getCCData(user: string, id: string){
    console.log('grabbing CC information', id, user);
        return new Promise((resolve, reject) =>
        {
        this._apiService.getAssertion(id).toPromise().then(assert =>
{
    return this._apiService.getToken(assert.toString(), user);
}).then((data: any) =>
{   
    return this._apiService.ccMeta(data.access_token.toString(), id);
}).then(parseString(Promise)).then((information: any) =>
{
    this.ccData.push(
    {
        key: 'userStatus',
        value: information.entry
    });
});

    resolve();
        });
}

I'm not sure if this is the correct way to design this function. Any extra insight would be great.

promise angular
1 Answers

The error indicates that then() expects a Function as parameter, while you provide it with the return value of another then() call, which is a Promise.

To resolve the error, change the calls inside the then()-calls to arrow functions:

for (const item of someArray) {
  this.getData1(item, userID).then(() =>
    this.getData2(item, userID).then(() =>
      this.userCheck(item)
    )
  );
}
user_95688530
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