Three import styles

threeWays.js

// way #1
import Storage from "storage";

class MyClass {
  setCache(data) {
    return Storage.insert(data);
  }
}


// way #2
import Storage from "storage";
const storage = new Storage();

class MyClass {
  setCache(data) {
    return storage.insert(data);
  }
}


// way #3

import Storage from "storage";
const storage = new Storage();

class MyClass {
  constructor(storage) {
    this.storage = storage;
  }
  
  setCache(data) {
    return storage.insert(data);
  }
}

// #4
export class Storage {}

//...
export class MyClass {
  constructor(storage) {
    this.storage = storage;
  }
  
  setCache(data) {
    return this.storage.insert(data);
  }
}

// Container State
import Storage from Storage;
import MyClass from MyClass;

export default new MyClass(new Storage());