How do I test JavaScript code with Jest?

Question

AI Bootstrap Builder · Accepted Answer

Jest is a popular testing framework for JavaScript, especially for applications built with React. It allows you to write tests with an easy-to-use API.


        
        // Example function to test
        function add(a, b) {
            return a + b;
        }

        // Jest test case
        test('adds 1 + 2 to equal 3', () => {
            expect(add(1, 2)).toBe(3);
        });

ADDITIONAL COMMENT:

Install Jest using npm with the command: "npm install --save-dev jest".
Create a JavaScript file with the function you want to test, e.g., "add.js".
Create a test file, e.g., "add.test.js", and include the test code as shown above.
Run your tests using the command: "npx jest".

- Jest automatically finds files with ".test.js" or ".spec.js" extensions. - Use "expect" to define assertions and "toBe" to check for equality. ✅ Answered with JavaScript best practices.

How do I test JavaScript code with Jest?

Asked on Sep 10, 2024

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