FAQ

Questions

Can I have multiple application containers?

Yes, no problem at all. If you want, they can even share tokens and hence instances!

Why getContainerSet is always async?

This is temporary(?) limitation to keep typescript happy and typescript types reasonably sane. In most real world scenarios your frontend dependencies are already async.

Why should I use ITI?

We strongly believe that helps to implement good DI patterns in your codebase and offers better tradeoffs compared to alternative DI frameworks or solutions. Check our alternatives section

How does handle circular dependency?

You can not create a circular dependency with iti and typescript. It will throw a typescript error if you try :)

import { createContainer } from "iti"

/*
// Part 1: You can create a circular dependency
// in your business logic
┌───┐   ┌───┐   ┌───┐   ┌───┐   ┌───┐
│ A │──▶│ B │──▶│ C │──▶│ D │──▶│ E │
└───┘   └───┘   └───┘   └───┘   └───┘
                  ▲               │
                  │               │
                  └───────────────┘
*/
class A {
  constructor() {}
}
class B {
  constructor(a: A) {}
}
class C {
  constructor(b: B, e: E) {}
}
class D {
  constructor(c: C) {}
}
class E {
  constructor(d: E) {}
}

// Part 2: You can't express a circular dependency because of typescript checks
createContainer()
  .add((ctx) => ({
    a: () => new A(),
  }))
  .add((ctx) => ({
    b: () => new B(ctx.a),
  }))
  .add((ctx) => ({
    // This line will throw a Typescript error at compile time
    c: () => new C(ctx.a, ctx.e),
  }))