Test the content of an in a React component with Enzyme</a></h1> </div> <div class="grid fw-wrap pb8 mb16 bb bc-black-075"> <div class="grid--cell ws-nowrap mr16 mb8" title="2016-01-12 19:07:53Z"> <span class="fc-light mr2">Asked</span> <time itemprop="dateCreated" datetime="2017-01-03T16:21:39.860" class="fromnow">Jan 03 '17 at 16:21</time> </div> <div class="grid--cell ws-nowrap mr16 mb8"> <span class="fc-light mr2">Active</span> <time class="fromnow" title="2019-08-07T20:21:40.283" datetime="2019-08-07T20:21:40.283">Aug 07 '19 at 20:21</a> </div> <div class="grid--cell ws-nowrap mb8" title="Viewed 8,190 times"> <span class="fc-light mr2">Viewed</span> 8,190 times </div> </div> <div id="mainbar" role="main" aria-label="questions and answers"> <div id="question" class="question" data-questionid="41447842" data-ownerid="372899" data-score="14"> <div class="post-layout"> <div class="votecell post-layout--left"> <div class="js-voting-container grid jc-center fd-column ai-stretch gs4 fc-black-200" data-post-id="41447842"> <button class="js-vote-up-btn grid--cell s-btn s-btnunset c-pointer"><svg aria-hidden="true" class="m0 svg-icon iconArrowUpLg" width="36" height="36" viewBox="0 0 36 36"><path d="M2 26h32L18 10 2 26z"></path></svg></button> <div class="js-vote-count grid--cell fc-black-500 fs-title grid fd-column ai-center" itemprop="upvoteCount" data-value="14">14</div> <button class="js-bookmark-btn s-btn s-btnunset c-pointer py4"> <svg aria-hidden="true" class="svg-icon iconBookmark" width="18" height="18" viewBox="0 0 18 18"><path d="M6 1a2 2 0 00-2 2v14l5-4 5 4V3a2 2 0 00-2-2H6zm3.9 3.83h2.9l-2.35 1.7.9 2.77L9 7.59l-2.35 1.7.9-2.76-2.35-1.7h2.9L9 2.06l.9 2.77z"></path></svg> <div class="js-bookmark-count mt4" data-value="0">0</div> </button> </div> </div> <div class="postcell post-layout--right"> <div class="s-prose js-post-body" itemprop="text"><p>I've written a simple React component that renders an <code><iframe></code>:</p> <pre><code>export class Iframe extends React.component { render() { return <iframe src={ this.props.src } />; } } </code></pre> <p>and I trying to test it by checking that the content loaded with <code>src</code> is properly populated within the <code><iframe></code>. In order to do so I try to access <code>frame.contentWindow</code>, but after mounting it with Enzyme it always returns <code>undefined</code>.</p> <p>I've tried to mock the <code><iframe></code> content with Sinon <a class="external-link" href="http://sinonjs.org/docs/#fakeServer" rel="noreferrer"><code>FakeXMLHttpRequest</code></a>:</p> <pre><code>server = sinon.fakeServer.create(); server.respondWith('GET', 'test', [200, { 'Content-Type': 'text/html' }, '<!DOCTYPE html><html xmlns="http://www.w3.org/1999/xhtml"><body><div class="myClass">Amazing Unicorn</div></body></html>']); container = mount(<Iframe src='test' />); </code></pre> <p>and with <a href="../../a/10419102#10419102"><code><iframe src='data:text/html' ></code></a>:</p> <pre><code>const src = 'data:text/html;charset=utf-8,<!DOCTYPE html><html xmlns="http://www.w3.org/1999/xhtml"><body><div class="myClass">Amazing Unicorn</div></body></html>'; container = mount(<Iframe src={ src } />); </code></pre> <p>but in both cases on the test with Enzyme:</p> <pre><code>container = mount(<Iframe src='...' />); container.instance().contentWindow // equals 'undefined' container.find('iframe').contentWindow // equals 'undefined' </code></pre> <p>The component works and renders as expected on the browser when provided with a valid <code>src</code> attribute. Is there any way to access <code>contentWindow</code> in React tests with Enzyme (or any other test framework)?</p></div> <div class="mt24 mb12"> <div class="post-taglist grid gs4 gsy fd-column"> <div class="grid ps-relative"> <a href="../../questions/tagged/javascript" class="post-tag js-gps-track" title="show questions tagged 'javascript'" rel="tag">javascript</a> <a href="../../questions/tagged/reactjs" class="post-tag js-gps-track" title="show questions tagged 'reactjs'" rel="tag">reactjs</a> <a href="../../questions/tagged/iframe" class="post-tag js-gps-track" title="show questions tagged 'iframe'" rel="tag">iframe</a> <a href="../../questions/tagged/sinon" class="post-tag js-gps-track" title="show questions tagged 'sinon'" rel="tag">sinon</a> <a href="../../questions/tagged/enzyme" class="post-tag js-gps-track" title="show questions tagged 'enzyme'" rel="tag">enzyme</a> </div> </div> </div> <div class="mb0"> <div class="mt16 grid gs8 gsy fw-wrap jc-end ai-start pt4 mb16"> <div class="grid--cell mr16 fl1 w96"></div> <div class="post-signature grid--cell"> <div class="s-user-card s-user-card"> <time class="s-user-card--time" datetime="edited May 23 '17 at 11:47">edited May 23 '17 at 11:47</time> <a href="../../users/-1/community" class="s-avatar s-avatar32 s-user-card--avatar"> <img class="s-avatar--image" src="../../users/profiles/-1.webp" data-jdenticon-width="32" data-jdenticon-height="32" data-jdenticon-value="Community" /> </a> <div class="s-user-card--info"> <a href="../../users/-1/community" class="s-user-card--link">Community</a> <ul class="s-user-card--awards"> <li class="s-user-card--rep" title="reputation score">1</li> <li class="s-award-bling s-award-blingsilver" title="1 silver badges">1</li> </ul> </div> </div> </div> <div class="post-signature owner grid--cell"> <div class="s-user-card s-user-card"> <time class="s-user-card--time" datetime="asked Jan 03 '17 at 16:21">asked Jan 03 '17 at 16:21</time> <a href="../../users/372899/axeeffect" class="s-avatar s-avatar32 s-user-card--avatar"> <img class="s-avatar--image" src="../../users/profiles/372899.webp" data-jdenticon-width="32" data-jdenticon-height="32" data-jdenticon-value="AxeEffect" /> </a> <div class="s-user-card--info"> <a href="../../users/372899/axeeffect" class="s-user-card--link">AxeEffect</a> <ul class="s-user-card--awards"> <li class="s-user-card--rep" title="reputation score">6,345</li> <li class="s-award-bling s-award-blinggold" title="4 gold badges">4</li> <li class="s-award-bling s-award-blingsilver" title="37 silver badges">37</li> <li class="s-award-bling s-award-blingbronze" title="33 bronze badges">33</li> </ul> </div> </div> </div> </div> </div> </div> <div class="post-layout--right js-post-comments-component"> <div id="comments-41447842" class="comments js-comments-container bt bc-black-075 mt12 " data-post-id="41447842" data-min-length="15"> <ul class="comments-list js-comments-list" data-remaining-comments-count="0" data-canpost="false" data-cansee="true" data-comments-unavailable="false" data-addlink-disabled="true"> <li id="comment-71307236" class="comment js-comment " data-comment-id="71307236" data-comment-owner-id="1818114" data-comment-score="0"> <div class="js-comment-actions comment-actions"> <div class="comment-score js-comment-edit-hide"> </div> </div> <div class="comment-text js-comment-text-and-form"> <a name="comment71307236_41447842"></a> <div class="comment-body js-comment-edit-hide"> <span class="comment-copy">I am having the same issue to test it, did you find a solution?</span> – <a href="../../users/1818114/weslley-araujo" title="668 reputation" class="comment-user ">Weslley Araujo</a> <span class="comment-date" dir="ltr"><a class="comment-link" href="../../questions/41447842/test-the-content-of-an-iframe-in-a-react-component-with-enzyme#comment71307236_41447842"><span title="2017-02-06T12:39:11.870 License: CC BY-SA 3.0" class="relativetime-clean">Feb 06 '17 at 12:39</span></a></span> </div> </div> </li> <li id="comment-80529719" class="comment js-comment " data-comment-id="80529719" data-comment-owner-id="1358661" data-comment-score="6"> <div class="js-comment-actions comment-actions"> <div class="comment-score js-comment-edit-hide"> <span title="number of 'useful comment' votes received" class="warm">6</span> </div> </div> <div class="comment-text js-comment-text-and-form"> <a name="comment80529719_41447842"></a> <div class="comment-body js-comment-edit-hide"> <span class="comment-copy">You would have to setup enzyme with a "working" browser. Don't know if that is possible. However, why should you want to test this? IMHO this test is pointless as you would not test your code but react. I think you should just test if the prop "src" is passed down correctly as the iframe's "src" attribute which is possible with enzyme.</span> – <a href="../../users/1358661/lipp" title="5,586 reputation" class="comment-user ">lipp</a> <span class="comment-date" dir="ltr"><a class="comment-link" href="../../questions/41447842/test-the-content-of-an-iframe-in-a-react-component-with-enzyme#comment80529719_41447842"><span title="2017-10-17T13:42:07.157 License: CC BY-SA 3.0" class="relativetime-clean">Oct 17 '17 at 13:42</span></a></span> </div> </div> </li> <li id="comment-84560736" class="comment js-comment " data-comment-id="84560736" data-comment-owner-id="452054" data-comment-score="0"> <div class="js-comment-actions comment-actions"> <div class="comment-score js-comment-edit-hide"> </div> </div> <div class="comment-text js-comment-text-and-form"> <a name="comment84560736_41447842"></a> <div class="comment-body js-comment-edit-hide"> <span class="comment-copy">contentWindow will be actually null not undefined, after you getDOMNode() and check property contentWindow. what you checked is property contentWindow on enzyme wrapper not iframe itself</span> – <a href="../../users/452054/maciejw" title="122 reputation" class="comment-user ">maciejW</a> <span class="comment-date" dir="ltr"><a class="comment-link" href="../../questions/41447842/test-the-content-of-an-iframe-in-a-react-component-with-enzyme#comment84560736_41447842"><span title="2018-02-14T04:15:24.520 License: CC BY-SA 3.0" class="relativetime-clean">Feb 14 '18 at 04:15</span></a></span> </div> </div> </li> </ul> </div> </div> </div> </div> <div id="answers"> <a name="tab-top"></a> <div id="answers-header"> <div class="answers-subheader grid ai-center mb8"> <div class="grid--cell fl1"> <h2 class="mb0" data-answercount="9">2 Answers<span style="display:none;" itemprop="answerCount">2</span></h2> </div> </div> </div> <a name="57401810"></a> <div id="answer-57401810" class="answer " data-answerid="57401810" data-ownerid="3267791" data-score="2" itemprop="suggestedAnswer" itemscope="" itemtype="https://schema.org/Answer"> <div class="post-layout"> <div class="votecell post-layout--left"> <div class="js-voting-container grid jc-center fd-column ai-stretch gs4 fc-black-200" data-post-id="57401810"> <button class="js-vote-up-btn grid--cell s-btn s-btnunset c-pointer"><svg aria-hidden="true" class="m0 svg-icon iconArrowUpLg" width="36" height="36" viewBox="0 0 36 36"><path d="M2 26h32L18 10 2 26z"></path></svg></button> <div class="js-vote-count grid--cell fc-black-500 fs-title grid fd-column ai-center" itemprop="upvoteCount" data-value="2">2</div> </div> </div> <div class="postcell post-layout--right"> <div class="s-prose js-post-body" itemprop="text"><p>The problem is still actual. And the answer is that jsdom provides contentWindow/contentDocument only for attached iframe, and enzyme by default doesn't attach nodes. There is option for mount which directs enzyme to attach node:</p> <pre><code>el = document.createElement('div'); document.body.appendChild(el); wrapper = mount(<MyReactNode />, { attachTo: el }); </code></pre></div> <div class="mb0"> <div class="mt16 grid gs8 gsy fw-wrap jc-end ai-start pt4 mb16"> <div class="grid--cell mr16 fl1 w96"></div> <div class="post-signature grid--cell"> <div class="s-user-card s-user-card"> <time class="s-user-card--time" datetime="answered Aug 07 '19 at 20:21">answered Aug 07 '19 at 20:21</time> <a href="../../users/3267791/oleg-gordeev" class="s-avatar s-avatar32 s-user-card--avatar"> <img class="s-avatar--image" src="../../users/profiles/3267791.webp" data-jdenticon-width="32" data-jdenticon-height="32" data-jdenticon-value="Oleg Gordeev" /> </a> <div class="s-user-card--info"> <a href="../../users/3267791/oleg-gordeev" class="s-user-card--link">Oleg Gordeev</a> <ul class="s-user-card--awards"> <li class="s-user-card--rep" title="reputation score">554</li> <li class="s-award-bling s-award-blingsilver" title="4 silver badges">4</li> <li class="s-award-bling s-award-blingbronze" title="6 bronze badges">6</li> </ul> </div> </div> </div> </div> </div> </div> <div class="post-layout--right js-post-comments-component"> </div> </div> </div> <a name="47940531"></a> <div id="answer-47940531" class="answer " data-answerid="47940531" data-ownerid="1317492" data-score="-4" itemprop="suggestedAnswer" itemscope="" itemtype="https://schema.org/Answer"> <div class="post-layout"> <div class="votecell post-layout--left"> <div class="js-voting-container grid jc-center fd-column ai-stretch gs4 fc-black-200" data-post-id="47940531"> <button class="js-vote-up-btn grid--cell s-btn s-btn__unset c-pointer"><svg aria-hidden="true" class="m0 svg-icon iconArrowUpLg" width="36" height="36" viewBox="0 0 36 36"><path d="M2 26h32L18 10 2 26z"></path></svg></button> <div class="js-vote-count grid--cell fc-black-500 fs-title grid fd-column ai-center" itemprop="upvoteCount" data-value="-4">-4</div> </div> </div> <div class="postcell post-layout--right"> <div class="s-prose js-post-body" itemprop="text"><p>If you're writing a unit test (and I assume that this is what you're doing), you should test the behavior, not the implementation details.</p> <p>If I had to write a test for such component I'd use smth like that:</p> <ul> <li>positive scenario: component renders an iframe with passed <code>src</code></li> <li>negative scenario: component renders null (depends on business logic) if no <code>src</code> passed in props</li> </ul> <p>This test handles both: correct and incorrect behavior. See <a class="external-link" href="https://en.wikipedia.org/wiki/Defensive_programming" rel="nofollow noreferrer"><em>Defensive programming</em></a> for more details.</p> <p>If we're talking about the test implementation, I'd use <a class="external-link" href="https://facebook.github.io/jest/" rel="nofollow noreferrer">Jest</a> and <code>toMatchSnapshot</code> method to check the rendering result on both scenarios.</p></div> <div class="mb0"> <div class="mt16 grid gs8 gsy fw-wrap jc-end ai-start pt4 mb16"> <div class="grid--cell mr16 fl1 w96"></div> <div class="post-signature grid--cell"> <div class="s-user-card s-user-card"> <time class="s-user-card--time" datetime="answered Dec 22 '17 at 11:10">answered Dec 22 '17 at 11:10</time> <a href="../../users/1317492/dmitry-volokh" class="s-avatar s-avatar32 s-user-card--avatar"> <img class="s-avatar--image" src="../../users/profiles/1317492.webp" data-jdenticon-width="32" data-jdenticon-height="32" data-jdenticon-value="Dmitry Volokh" /> </a> <div class="s-user-card--info"> <a href="../../users/1317492/dmitry-volokh" class="s-user-card--link">Dmitry Volokh</a> <ul class="s-user-card--awards"> <li class="s-user-card--rep" title="reputation score">1,630</li> <li class="s-award-bling s-award-blingsilver" title="16 silver badges">16</li> <li class="s-award-bling s-award-bling__bronze" title="28 bronze badges">28</li> </ul> </div> </div> </div> </div> </div> </div> <div class="post-layout--right js-post-comments-component"> </div> </div> </div> </div> </div> </div> </div> <script src="../../static/js/stack-icons.js"></script> <script src="../../static/js/fromnow.js"></script> </body> </html>