I have a React app and I'm trying to create a basic Jest unit test. I've created a basic Calculator class like this within a Calculator.js file:
class Calculator{
add(num1, num2){
return num1 + num2;
}
}
export default Calculator;
At the same level, I've created a new Jest unit test named Calculator.test.js like this:
import './Calculator';
test('adds 1 + 2 to equal 3', () => {
expect(new Calculator().add(1, 2)).toBe(3);
});
However, when the Jest test harness runs, the following error gets output:
ReferenceError: Calculator is not defined 3 | 4 | test('adds 1 + 2 to equal 3', () => { > 5 | expect(new Calculator().add(1, 2)).toBe(3); | ^ 6 | }); 7 | at Object.<anonymous> (src/services/Calculator.test.js:5:14)
Any idea what I'm doing wrong with this particular implementation?
Try this in your Calculator.test.js:
import Calculator from './Calculator';
Empty import (as in import './Calculator';) only loads the module, but doesn’t actually import anything.