把最实用的前端技术
讲得一看就懂

type EventName<T extends string> = `on${Capitalize<T>}`
// produces: 'onClick' | 'onChange' | 'onSubmit'

type DomEvents = EventName<'click' | 'change' | 'submit'>
// type safe CSS properties

type CSSVar<T extends string> = `--${T}`

type Config = {
  theme: 'light' | 'dark' | 'system'
  colors: Record<string, string>
}
// with a normal annotation you lose the literal type
const config1: Config = {
  theme: 'dark',