Destructuring a possibly `undefined` object not caught, throws an error at runtime

🔎 Search Terms

destructuring, Cannot destructure as it is undefined, optional chaining destructuring

🕗 Version & Regression Information

• This changed between versions ______ and _______
• This changed in commit or PR _______
• This is the behavior in every version I tried, and I reviewed the FAQ for entries about _________
• I was unable to test this on prior versions because _______

⏯ Playground Link

https://www.typescriptlang.org/play/?ts=5.6.2#code/MYewdgzgLgBAlmADgVygLhgbwLACgYEwCGA-BpjAEZlYzAbQBOCA5jAL4d6cC8tRGZGAAmAUwBmCUcK648oSLAoA6VZQ4w+CFFGWlllIA

💻 Code

const input: {
    a?: { b?: { c: string } }
} = { a: undefined }

const { ...b } = input.a?.b

🙁 Actual behavior

No error reported by TypeScript.

🙂 Expected behavior

TypeScript should have an indicative error, since this expression might result in undefined, which cannot be destructured.

Similar to this:

Rest types may only be created from object types.(2700)

Additional information about the issue

The error in the JavaScript being ran is:

Uncaught TypeError: Cannot destructure '(intermediate value)' as it is undefined.

Comienza con el enlace al Playground de TypeScript 5.6.2 y el ejemplo de destructuring que incluye input.a?.b. Traza cómo el checker gestiona un objeto que posiblemente sea undefined en una expresión de object-rest destructuring y, a continuación, verifica que el comportamiento completado emita un diagnostic indicativo en lugar de permitir código que lanza un error en tiempo de ejecución.