Skip to content

Instantly share code, notes, and snippets.

@hallettj

hallettj/expanding-nonnullable.ts Secret

Created January 22, 2019 19:15
Show Gist options
  • Star 0 You must be signed in to star a gist
  • Fork 0 You must be signed in to fork a gist
  • Save hallettj/7dab80dfe032baff9483d9da14c46077 to your computer and use it in GitHub Desktop.
Save hallettj/7dab80dfe032baff9483d9da14c46077 to your computer and use it in GitHub Desktop.
Download ZIP
Raw
expanding-nonnullable.ts
NonNullable<string | null>
// The conditional distributes over each branch in `string | null`.
== (string extends null | undefined ? never : string) | (null extends null | undefined ? never : null)
// The conditional in each union branch is resolved.
== string | never
// `never` factors out of the resulting union type.
== string
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment