Simple example

Dummy todo app built with typectx.

import { createMarket, index } from "typectx"

// 1. Create a market
const market = createMarket()

// 2. Define data (resources) and services (products)
const $session = market.offer("session").asResource<{ userId: string }>()
const $todosDb = market.offer("todosDb").asProduct({
    suppliers: [],
    factory: () => new Map<string, string[]>() // Simple in-memory DB
})
const $addTodo = market.offer("addTodo").asProduct({
    suppliers: [$session, $todosDb],
    factory:
        ({ session, todosDb }) =>
        (todo: string) => {
            const userTodos = todosDb.get(session.userId) || []
            todosDb.set(session.userId, [...userTodos, todo])
            return db.get(session.userId)
        }
})

/*Here, we define two types of suppliers:

-   `$session`: A **Resource** supplier that will hold the current user's session data.
-   `$todosDb`: A **Product** supplier that provides an in-memory `Map` to act as a database. It has no dependencies.
-   `$addTodo`: A **Product** supplier that creates our main `addTodo` function. It depends on both the `$session` and `$todosDb`. */

const session = { userId: "user123" }

// 3. Assemble and use
const addTodo = $addTodo
    // We only need to provide resource dependencies to assemble(). Products are auto-wired
    .assemble(index($session.pack(session)))
    .unpack()

console.log(addTodo("Learn typectx")) // ["Learn typectx"]
console.log(addTodo("Build app")) // ["Learn typectx", "Build app"]