Base generic type for weak nominal typing in Typescript
npm install ts-taggedDefines the Tagged generic type letting you created tagged types with base type T and name N.
Two variables of a tagged type can only be assigned to each other if they have the same base type and name.
This implements a weak form of nominal typing suitable for types shared across multiple packages.
``bash`
npm install -S ts-tagged
`typescript
import { Tagged } from "ts-tagged";
type Email = Tagged
type DisplayName = Tagged
const email: Email = "foo@example.com";
const displayName: DisplayName = "Foo Bar";
function sendEmail(recipient: Email) {
// ...
}
sendEmail(email); // OK
sendEmail(displayName); // Compilation error: the names don't match
sendEmail("bar@example.com"); // OK: Unnamed, but the base type matches
sendEmail(42); // Compilation error: The base type does not match
``