I was playing around with TS interface features, and I saw that setting a custom property configuration (Object.defineProperty) on an object that implements an interface with "readonly" is passing TS checks for the "readonly" interface property.

  interface SomeInterface {
    readonly x: number;
  }

  let obj: SomeInterface = { x: 10 };

  Object.defineProperty(obj, 'x', { value: 5 });
  //obj.x = 5; //Error: Cannot assign to 'x' because it is a read-only property.ts(2540)
  console.log(obj.x); //will output 5

Expected behavior:
"Error: Cannot assign to 'x' because it is a read-only property..."
Since readonly property is being modified

Actual behavior:
Readonly property is writable

Related Issues:
#29634