RxJs / Angular: Changing a request parameter after a failure using retry

I'm making a request for a window of data based on a date and a range. The result of the request can be empty requiring me to make another request and change some parameters. The previous way I made the request was a recursive function that worked well but it can be a lot better.

Using a combination of rxjs pipe operators this can be one chain that works beautifully.

  

constructor(private http: HttpClient){}

someFunction() {
    const retryObject = { foo: 1};
    return of(retryObject)
        .pipe(
            switchMap(obj => {
        return this.http(`http://some.name?foo=${obj.foo}`);
    }),
    map(result => {
        if (result.error) {
            // Update the foo value and it will try the request again with the new value
            retryObject.foo++;
            throw 'an error happened';
        }
        // Happy path
    }),
    retry([HOW MANY TIMES YOU WANT TO TRY THE REQUEST])
).subscribe(result => {
        // Do something with your data
    })
}

The magic here is the retry pipe in combination with throwing an error. The linked page used throwError but it didn't retry the request. You can't pass in a string or number into the of operator. Javascript is pass-by-value for those. You need a reference to an object that can be updated.