Here is my ts code

var el:number|null
export const im=function(){
  if (el==null){
    const ans= {
      exists:false
    }
    return ans
  }
  const ans2={
    value:7,    
    exists:true,

  }    
  return ans2
}()

By looking at the code, the type of im should be:

const im2: {
    value: number;
    exists: boolean;
} | {
    exists: boolean;
}

But in reality it is not. the generated .d.ts reads:

export declare const im2: {
    exists: boolean;
};

my question is: why is it?