How to pass a param to HttpInterceptor?

Maybe there’s a better way to handle this problem, but as a workaround you can create and pass custom HttpParams to request and then check them in the interceptor. For example:

export class CustomHttpParams extends HttpParams {
  constructor(public param1: boolean) {
   super();
  }
}

Using this class in http call:

this.http.get('https://example.com', {
  params: new CustomHttpParams(true)
})

And now in interceptor:

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
  if (request.params instanceof CustomHttpParams && request.params.param1) 
    request = request.clone({
      setHeaders: {
        'header1': 'xxxxxx'
      }
    });
  else
    request = request.clone({
      setHeaders: {
        'header2': 'yyyyyy'
      }
    });

  return next.handle(request);
}