Using a callback function for creating refs can give you more control over how the ref is created, set and unset. If you are using versions of React earlier than version 16.3, then this should be your preferred method of creating refs. Using a callback ref, our previous code snippet will become the following. It’s important to validate that everything works in your production React app as expected. That would be the preference as I'm asserting the children of the frame component. We initialized the state of the component with an uppercase property set to false. Calling preventDefault() for a non-cancelable event has no effect.. Notice in the render() method that we added the ref we created to the component we created earlier. React provides three major ways of creating refs. React executes components multiple times, whenever it senses the need. Most of the modern frameworks provide APIs through which you can access the native DOM representation of your app, and React is not an exception. http://stackoverflow.com/questions/40852131/cant-get-ref-in-jest-tests, Upgrade dependencies to fix build breakages, https://travis-ci.org/graphql/graphiql/builds/181453346, https://travis-ci.org/graphql/graphiql/builds/182431531, Upgrade dependencies to fix build breakages (, TypeError: Cannot read property 'length' of null, [client testing] Jest snapshot testing is not supported, Fail snapshot test after including the typeahead, Cannot test with storyshots due to findDomNode, Portal: rework #handleRef to avoid using ReactDOM.findDOMNode, Menu and MenuItem thorw "Invariant Violation: getNodeFromInstance: Invalid argument" in snapshot test with jest, https://github.com/ericgio/react-bootstrap-typeahead/, Replaced findDomNode with ref in order to use react-test-renderer for snapshot testing with storybook, Mock rc-select due to findDOMNode not being supported, jest snapshot tests are failing with invariant Violation, Jest snapshot testing - ReactTestRenderer: Invariant Violation: getNodeFromInstance: Invalid argument, Unable to generate Snapshot for antd Table with Jest, [test] Jest snapshot testing "getNodeFromInstance: Invalid argument", TypeError: Cannot read property 'ownerDocument' of null - when using react-test-renderer, Unable to find node on an unmounted component, TypeError: this._touchableNode.addEventListener is not a function, Remove placeholder from API once upgraded to React 16, Replace string ref with callback ref to support jest snapshots, Console.error logged when running component from inside react-test-renderer, Error during Jest unit test run after upgrading to react 16.6.0: Invariant Violation: Unable to find node on an unmounted component, TypeError: element.setAttribute is not a function The above error occurred in the component, Storybook shoryshots + Recharts(option: IntersectionObserver) Error, TypeError: _this.ref.current.querySelector is not a function, fix(Ref): do not return Fibers as refs for "react-test-renderer", You can mock it out (assuming you use Jest), In the future test renderer could provide a first-class component mocking API out of the box, unrelated to Jest. The main emphasis is on the string ref we created on the element. Note that we can only create refs on class components since they create an instance of the class when mounted. Already on GitHub? 9 min read Starting from React 16.3, the React API included a new createRef() method that can be used for creating refs in much the same way as we did using the callback function. For some reason I still can't use ref in jest tests. Something like: Finally, as last option, you can mock react-dom itself.

First with null, then again with the DOM element. This is worth noting for refs created with React.createRef(). Specifies the function to run when the event occurs. Refs work with test renderer in master, and you can even mock them to return something else instead of null: There are no plans to support findDOMNode() in test renderer because it should be agnostic of React DOM and there is no way to implement it in a way that won't break in the future.