Test return value of function with Jest in React
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If you need to access a class method in your test, it will be available as a property on the return of the instance method for your wrapper.
const wrapper = shallow(<MyComponent />);
expect(wrapper.instance().doSomethingFancy()).toEqual(true);
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Modular Integration
Updated on January 22, 2021Comments
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Modular Integration over 3 years
How would I test the return value in the "doSomethingFancy" function in this React code? I tried to find a super simple example and couldn't find anything. So I would like to write a test that checks that the number 2 is returned. I know it doesn't really return to anything as I wrote this as an example so I can learn how to write tests for my React application.
import React from 'react'; class FancyStuff extends React.Component { render() { return <div> <h1> Hello, {this.props.name} </h1> <button onClick={this.doSomethingFancy}> Add 1 + 1! </button> </div>; } doSomethingFancy(e) { e.preventDefault(); let value = 1 + 1; return value; } }; export default FancyStuff;