How do I deal with localStorage in jest tests?

Question

I keep getting \"localStorage is not defined\" in Jest tests which makes sense but what are my options? Hitting brick walls.

Answer 1

You need to mock local storage with this snippets

// localStorage.js

var localStorageMock = (function() {
    var store = {};

    return {
        getItem: function(key) {
            return store[key] || null;
        },
        setItem: function(key, value) {
            store[key] = value.toString();
        },
        clear: function() {
            store = {};
        }
    };

})();

Object.defineProperty(window, 'localStorage', {
     value: localStorageMock
});

And in the jest config:

"setupFiles":["localStorage.js"]

Feel free to ask anything .