Compile-Time State Machine Guards with Phantom Types

type Draft = { state: 'DRAFT' };
type Published = { state: 'PUBLISHED' };
 
class DocumentProcess<State> {
  constructor(public readonly content: string) {}
 
  static create(content: string): DocumentProcess<Draft> {
    return new DocumentProcess<Draft>(content);
  }
}
 
function publishDocument(
  doc: DocumentProcess<Draft>
): DocumentProcess<Published> {
  return new DocumentProcess<Published>(doc.content);
}
 
const draftDoc = DocumentProcess.create('Framework Core RFC');
const publishedDoc = publishDocument(draftDoc);
// publishDocument(publishedDoc); // Compile Error: Argument of type 'DocumentProcess<Published>' is not assignable to 'DocumentProcess<Draft>'