known-keys.mdx

title	description	date	authors	draft
Known keys	When you need an object where all the keys are mapped to one type except some known keys that are mapped to different types.	2024-02-20	pomber	true

Sources:

• microsoft/TypeScript#31153
• https://github.dev/sindresorhus/type-fest/blob/main/source/merge.d.ts

type MyType = {
  [s: string]: string
  foo: number
}

When you need an object where all the keys are mapped to one type except some known keys that are mapped to different types.

Why Omit doesn't work:

type Omit<T, K extends keyof T> = Pick<T, Exclude<keyof T, K>>

interface FancyIndices {
  [x: symbol]: number
  [x: `${string}Token`]: string
}

does this work?