CASL subject example

casl.js

class Todo {
  constructor({ title, assignee }) {
    this.title = title;
    this.assignee = assignee;
  }
}

const myTodo = new Todo({
  title: "buy food",
  assignee: "me"
});

const johnTodo = new Todo({
  title: "read the book",
  assignee: "John"
});

const ability = new Ability(defineAbilitiesFor("member"));

console.log("can read my todo?", ability.can("read", myTodo)); // true
console.log("can close my todo?", ability.can("close", myTodo)); // true

console.log("can read John's todo", ability.can("read", johnTodo));  // true
console.log("can close John's todo?", ability.can("close", johnTodo)); // false

https://codesandbox.io/s/4qxj4y2l99?expanddevtools=1&fontsize=14&view=preview