[FIXED] how to cover values ​that are in a component with tests jest

Issue

is it possible to write tests in jest for a component that is, as it were, inside? that is, I do not have the ability to make the data values ​​​​incremental in the function, they are inside the function, just a simplified example

export default function App() {
      let test1 = 10;
      let test2 = 5;
    
      if (test1 !== test2) {
        console.log("1");
      }
    
      return (
        <div className="App">
          <h1>Hello CodeSandbox</h1>
          <h2>Start editing to see some magic happen!</h2>
        </div>
      );
    }

https://codesandbox.io/s/hungry-bouman-5x293t?file=/src/App.tsx:24-286

Solution

It is not possible to test for the private internals of functions.

The only way you could test it, would be by having it in separate function (just a simple util function) and test separately there. After that just import it anywhere you need.

This means doing something like this

const areTestValueMatching = (test1, test2) => {
  if (test1 !== test2) {
      return false;
  }
  return true
}

it("returns true if test values are matching", () => {
  expect(areTestValueMatching(1, 2)).toBe(false)
})

And then importing areTestValueMatching function into your function component.

Answered By - MalwareMoon
Answer Checked By - - Marilyn (ReactFix Volunteer)