effect-io-ai

Package: effect
Module: Context

Context.pick

Returns a new Context that contains only the specified services.

When to use

Use when you want to keep an allowlist of services in a Context.

Example (Picking services from a context)

import { Context, Option, pipe } from "effect"
import * as assert from "node:assert"

const Port = Context.Service<{ PORT: number }>("Port")
const Timeout = Context.Service<{ TIMEOUT: number }>("Timeout")

const someContext = pipe(
  Context.make(Port, { PORT: 8080 }),
  Context.add(Timeout, { TIMEOUT: 5000 })
)

const context = pipe(someContext, Context.pick(Port))

assert.deepStrictEqual(
  Context.getOption(context, Port),
  Option.some({ PORT: 8080 })
)
assert.deepStrictEqual(Context.getOption(context, Timeout), Option.none())

See

• omit for removing selected services

Signature

declare const pick: <S extends ReadonlyArray<Key<any, any>>>(...services: S) => <Services>(self: Context<Services>) => Context<Services & Service.Identifier<S[number]>>

Source

Since v2.0.0