const company: Partial<Company> = {
  ...(update.name ? { name: update.name } : null),
  ...(update.email ? { email: update.email } : null),
  ...(update.alias ? { aliassssss: update.alias } : null), // no error
};

declare const someCondition: boolean;

type MyObject = { foo: number } & ({ bar: number } | {});

const a: MyObject = {
    foo: 1,
    // ✅ Error
    bar: 'foo',
};

const b: MyObject = {
    foo: 1,
    ...(someCondition
        ? {
              // ❌ Expected error, got none
              bar: 'foo',
          }
        : {}),
};

type Bar = {
    a: string; 
};

type Chaz = {
    a: string, 
    c: "zip" | "zap"
}

function usesBar(value: Bar, c: "zip" | "zap") : Chaz {
    return {
        c, 
        ...value, // The excess properties will clobber the c value!
    }; 
}

const d = {
    a: "hello", 
    c: "blah blah blah"
}; 

const e = usesBar(d, "zip"); 
console.log(e);
// {
//  "c": "blah blah blah",
//  "a": "hello"
// }

type Params = {
  a?: any;
  b?: any;
}

function func (params: Params) {
  return;
}

const objWithAllowedKeys = { a: 2 }
const objWithForbiddenKeys = { c: 2 }

func({ ...objWithAllowedKeys }) // valid - no error ✅
func({ ...objWithForbiddenKeys }) // valid - error ✅
func({ ...objWithAllowedKeys, ...objWithForbiddenKeys }) // invalid - why no error? ❌