Q: Typescript - Cannot use 'new' with an expression whose type lacks a call or construct signature I'm trying to connect to PouchDB Database and i got the error 
Typescript Cannot use 'new' with an expression whose type lacks a call or construct signature

Below is my code:-
var PouchDB = require("pouchdb"); 

@Injectable()
export class PouchDBService {

  private isInstantiated: boolean;
  private database: any;

  public constructor(private http: Http) {
    if(!this.isInstantiated) {

      this.database = new PouchDB("db_name"); <--error at this line
      this.isInstantiated = true;
    }


A: @types/pouchdb might be helpful in this case.

A: You might need  to pouchdb as the following:
import * as PouchDB from "pouchdb";

and then can do:
  this.database = new PouchDB("db_name"); //should work

