tcomb-loves-immutable-js.js

const t = require("tcomb");
// imstruct is a tcomb type builder that internally builds an
// Immutable.Record object, but applies tcomb's type system to it
const imstruct = require("../util/imstruct");

const Person = imstruct({
  name: t.String,
  age: t.Number
});

const Address = imstruct({
  person: Person,
  city: t.String,
  state: t.String
})

// Create immutable records
const l = Person({ name: "James", age: 7 });
console.log(l.name); // -> "James"
console.log(l.get("name")); // -> "James"

console.log(l.set("name", "sarah");
// -> { name: "sarah", age: 7 }

// This will throw an error: `Invalid value "foo" supplied to age: Number`
Person({ name: "James", age: "foo" });

// Create composite types
const addr = Address({
  person: Person({ name: "James", age: 7 }),
  city: "Richmond",
  state: "VA"
});

console.log(addr.getIn(["person", "name"])); // -> "James"

console.log(addr.setIn(["person", "name"], "Sarah"));
// ->
// { person: { name: "Sarah", age: 7 },
//   city: "Richmond",
//   state: "VA" }

// This will throw an error:
// `Invalid value "badAge" supplied to age: Number`
console.log(addr.setIn(["person", "age"], "badAge"));