How to mock/consider javascript prototype functions by default in jest test cases

Question

The following code throws error as : TypeError: Cannot read property 'trim' of undefined

      this.setState({
        details: {
          ...this.state.details,
          [classificationType]: [value.trim()]
        }
      });

How to improve jest test cases to consider string features?

Answer 1

Might be you are not getting value that's why it is unable to read trim() function on that. Can you please explain from where you are getting value ? What mock data you used to execute your test case?