effect-io-ai

Package: effect
Module: Types

Types.Has

Checks whether an object type contains any of the specified keys.

When to use

Use to branch type-level logic when at least one key from a candidate key set exists on an object type.

Details

Returns true if at least one key from Key exists in A, false otherwise.

Example (Checking key presence)

import type { Types } from "effect"

type Yes = Types.Has<{ a: number; b: string }, "a" | "c"> // true
type No = Types.Has<{ a: number }, "b" | "c"> // false

Signature

type Has<A, Key> = (Key extends infer K ? K extends keyof A ? true : never : never) extends never
  ? false
  : true

Source

Since v2.0.0