How can I test code using the module pattern?

How can I test code using the module pattern?

The module pattern helps encapsulate code, making it easier to test. You can create a module and expose methods for testing.

Can you show me an example of a module pattern?

Sure! Here's a simple example:

const MyModule = (function() {
    let privateVar = 'I am private';
    return {
        publicMethod: function() {
            return privateVar;
        }
    };
})();

You can test publicMethod to ensure it returns the expected value.

How do I write tests for this module?

You can use a testing framework like Mocha or Jest. For example, with Jest:

test('publicMethod returns privateVar', () => {
    expect(MyModule.publicMethod()).toBe('I am private');
});

What if I want to test private methods?

Testing private methods directly is not recommended. Instead, focus on testing the public interface of your module.