JS Design Patterns: Proxy, see more at: https://medium.com/p/b8f962affe02

DESIGN_PATTERNS_accessControlWithoutProxyPattern.js

class Products {
  constructor(User) {
    if (typeof User !== "object") {
      throw new Error("User object is required to initialize products class");
      return false;
    }
    this.currentUser = User;
    this.data = [];
  }

  checkPrivilege(permision) {
    const userHasThisPermission = this.currentUser.permissions.some(
      currentPermission => permision === currentPermission,
    );

    return userHasThisPermission;
  }

  add(product) {
    if (this.checkPrivilege("product_add")) {
      this.data.push(product);
      return true;
    }

    return false;
  }

  remove(product) {
    if (this.checkPrivilege("product_remove")) {
      this.data = this.data.filter(
        currentProduct => product !== currentProduct,
      );

      return true;
    }

    return false;
  }

  reports() {
    if (this.checkPrivilege("product_reports")) {
      return `Products reports`;
    }

    return false;
  }
}

class User {
  constructor(name, permissions) {
    this.name = name;
    this.permissions = permissions;
  }
}

const run = () => {
  const productInstanceWithUser1 = new Products(
    new User("Ricardo", ["product_reports"]),
  );

  console.log(
    `User without access to add method tries add new product `,
    productInstanceWithUser1.add("New product"),
  );

  console.log(
    `User without access to add method tries remove product `,
    productInstanceWithUser1.remove("New product"),
  );

  console.log(
    `User with access to report method tries generates a report `,
    productInstanceWithUser1.reports(),
  );
};

run();