Define 'tagName' values in Element interfaces to prevent misleading type acceptance.

Bug Report

🔎 Search Terms

• HTML Element Interfaces
• Element tagName
• Element Interfaces
• Incorrect element types accepted

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about Element interfaces

⏯ Playground Link

Playground link with relevant code

💻 Code

// Elements can be assigned to variables of other element types because of interface overlaps being sufficient.
let element: HTMLSpanElement = document.createElement("div");

// If the interfaces included the appropriate 'tagName' property this could be avoided...
let spanElement: HTMLSpanElement & { tagName: "SPAN" } = document.createElement("div") as HTMLDivElement & { tagName: "DIV" };

🙁 Actual behavior

e.g. 'HTMLDivElement' instance can be assigned to variables of type 'HTMLSpanElement'.

🙂 Expected behavior

This should fail the type checking to avoid accidentally assigning elements of an incorrect type.

Inizia dalla riproduzione collegata di TypeScript Playground ed esamina le interfacce HTML Element coinvolte, in particolare tagName su HTMLSpanElement e HTMLDivElement. Il lavoro è completato quando un HTMLDivElement non viene più accettato come HTMLSpanElement, mentre il comportamento mostrato dell’intersezione di tagName continua a essere rappresentato accuratamente.