Faking internal calls

[danruziska]

Hi,

I'd like to know how to mock internal calls in this specific scenario:

module1.js

function function1() {
  //Some logic code
  return module2.function2(arg1);
}

I want to fake function2, but the code under test, which is function1, runs the real implementation.

Right now, I'm stuck with this solution:

const module1 = require('path/to/module1.js');

it('should return fake function2', () => {
  //Arrange
  let function2Return = {
    test:'test',
    test2:'test2'
  };
  //module2.js contains function2()
  let mod2= testdouble.replace('path/to/module2.js');
  testdouble.when(mod2.function2().thenReturn(
    function2Return
  )); 
  //Act
  //module1.js contains function1()
  let result = module1.function1();
  //Assert
  assert.strictEqual('test2',result.test2);
});

How do I tie the real implementation of function1() with the fake implementation of function2()?

Thanks

[searls]

You need to require module1 after you've replaced module2.

it('should return fake function2', () => {
  //Arrange
  let function2Return = {
    test:'test',
    test2:'test2'
  };
  //module2.js contains function2()
  let mod2= testdouble.replace('path/to/module2.js');
  const module1 = require('path/to/module1.js'); // <-- like this
  testdouble.when(mod2.function2().thenReturn(
    function2Return
  )); 
  //Act
  //module1.js contains function1()
  let result = module1.function1();
  //Assert
  assert.strictEqual('test2',result.test2);
});