Macro

Macro is similar to a function that has control over the lifecycle event, schema, context with full type safety.
Once defined, it will be available in a hook and can be activated by adding the property.

import { Elysia } from 'elysia'

const plugin = new Elysia({
  name: 'plugin'
}).macro({
  hi: (word: string) => ({
    beforeHandle() {
      console.log(word)
    }
  })
})

const app = new Elysia()
  .use(plugin)
  .get('/', () => 'hi', {
    hi: 'Elysia'
  })

Accessing the path should log “Elysia” as the results.

Property shorthand

Starting from Elysia 1.2.10, each property in the macro object can be a function or an object.
If the property is an object, it will be translated to a function that accepts a boolean parameter, and will be executed if the parameter is true.

import { Elysia } from 'elysia'

export const auth = new Elysia()
  .macro({
    // This property shorthand
    isAuth: {
      resolve: () => ({
        user: 'saltyaom'
      })
    },
    // is equivalent to
    isAuth(enabled: boolean) {
      if (!enabled) return

      return {
        resolve() {
          return { user }
        }
      }
    }
  })

API

macro has the same API as a hook.
In the previous example we create a hi macro that accepts a string.
We then assigned hi to "Elysia", the value was then sent back to the hi function, and then that function added a new event to the beforeHandle stack.

This is equivalent to pushing a function to beforeHandle as follows:

import { Elysia } from 'elysia'

const app = new Elysia()
  .get('/', () => 'hi', {
    beforeHandle() {
      console.log('Elysia')
    }
  })

macro shines when a logic is more complex than simply accepting a new function—for example, creating an authorization layer for each route.

import { Elysia } from 'elysia'
import { auth } from './auth'

const app = new Elysia()
  // …

The code snippet above is truncated.