I am trying to test a function that is declared inside another function(Parent). I tried a few things but was not able to test that. I am using react library and JEST testing framework in the project.

Here is the service file (service.ts) function which I am trying to test:

import { useThisHook } from './base-hooks';

export function someFunction(param: string) {

  const [
    resolveFunction,
    ,
    { loading, error },
  ] = useThisHook();
  
  const childFun = (param : number) => {
     resolveFunction(someArguments);
  }
  
  return{
     someValue: childFun
  }
}

Here is the spec file code:

import * as SomeHooks from './base-hooks';
import * as Service from './service';

describe('Service function', () => {
  beforeEach(() => {
     jest.spyOn(SomeHooks, 'useThisHook').mockReturnValue(
      {
         //Some Value
      }
     );
  });

  test('Some function test', () => {
    const someFunctionResponse = Service.someFunction('string');

    expect(someFunctionResponse).toEqual({
        someValue: expect.any(Function),
    });
  });
});

Till here it is fine. Tests are also getting passed but the problem is that childFn is not getting the coverage and that's what my requirement is. I am new to React and Jest. I am not able to understand how can I achieve that. I tried many things but didn't succeed.