JS `Object.defineProperty` declaration can't define divergent accessors

🔎 Search Terms

divergent accessors setter getter expando js jsdoc

🕗 Version & Regression Information

• This is the behavior in every version I tried

⏯ Playground Link

https://www.typescriptlang.org/play?filetype=js#code/MYewdgzgLgBAHjAvDA3gXwNwCgsHkBGAVgKbBQB0AJsQGYCWYxACgE4gAOxLUAngBRwANDABEUYtBHCUWGDAD0AKkUwAAi2JQAri0ipoLBgHM0MRfNkwjmvgEpUluRu27RI7HLSDLSlavYAhiwBALaoYFoh+FymAWYWchA2Afbo3mi22Fg0WmBkdOAwdBAgADYB4gBibCEAonCBYJQgAIIQEHRGYCHEYFAQAEIMlMZ2DnJw5OLQSDAALABMGAryMFxsLDD4WrAQABYgWqWUW8QwuADSWGhYQA

💻 Code

const x = {};

Object.defineProperty(x, "test", {
  /** @returns {string} */
  get() {
    return "";
  },
  /** @param {number} a */
  set(a) {},
});

function isolateFromExpandoAssignmentsBinding() {
  x.test = 42; // error but should be OK
}

🙁 Actual behavior

The write type of this expando member is string

🙂 Expected behavior

The write type of this expando member should be number since divergent accessors are allowed nowadays

Additional information about the issue

No response

Start by running the playground link and the minimal Object.defineProperty example to reproduce the divergent getter and setter types. Trace how the TypeScript type checker determines the write type for this expando member, then verify that x.test accepts number while preserving the getter's string type.