Provide an interface that lists the known environment names

[sapphi-red]

Description

It would be nice if we can provide input suggestions for

• the config:

  export default defineConfig({
    environments: {
      s
      ^^^ input suggestion here
    }
  })

• codes in meta-frameworks:

  server.environments.s
                      ^^^ input suggestion here

Suggested solution

Add the KnownEnvironment type that lists the known environment names

// this `Record<string & {}, never>` is to force the value of extended keys to be `never`
interface KnownEnvironment extends Record<string & {}, never> {
  client: never
  ssr: never
}
type KnownEnvironmentNames = keyof KnownEnvironment

type Environments = Partial<Record<KnownEnvironmentNames, string>>

Plugins / Meta-frameworks can extend by:

declare module 'vite' {
  interface KnownEnvironment {
    myEnv: never
  }
}

Alternative

No response

Additional context

This is also useful for vitejs/ecosystem#10

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.