Object spread works for unconstrained generic

TypeScript Version: 3.8.3

Search Terms:
generic
spread
unrestrained
unrestricted

Expected behavior:
The spread function should not compile because T is not constrained to a type that can be spread.

Actual behavior:
It compiles.

Related Issues:
https://github.com/microsoft/TypeScript/issues/30129
https://github.com/microsoft/TypeScript/pull/13288

Code

function spread<T>(t: T) {
  // This should not compile
  return { ...t };
}

// The type of `result` is `number` even though the value of `result` is `{}`
const result = spread(5);

"use strict";

function spread(t) {

    // This should not compile

    return Object.assign({}, t);

}

// Result is still a number when in reality it's {}

const result = spread(5);

{
  "compilerOptions": {
    "noImplicitAny": true,
    "strictNullChecks": true,
    "strictFunctionTypes": true,
    "strictPropertyInitialization": true,
    "strictBindCallApply": true,
    "noImplicitThis": true,
    "noImplicitReturns": true,
    "alwaysStrict": true,
    "esModuleInterop": true,
    "declaration": true,
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true,
    "moduleResolution": 2,
    "target": "ES2017",
    "jsx": "React",
    "module": "ESNext"
  }
}

Playground Link: Provided

Reproduisez le comportement dans le lien Playground fourni avec TypeScript 3.8.3 et les options du compilateur indiquées. Lisez l’issue et la pull request associées, puis suivez la gestion par le compilateur de object spread pour un unconstrained generic. Le travail est terminé lorsque l’exemple est rejeté comme prévu et que le type résultant ne reste plus incorrectement le type de l’argument.