title: Why isn't object-fit working in flexbox?
body: <p>I have several columns that I am giving equal width using flex. Each contains <code>img</code> tags, and I'd like those images to exhibit the <code>object-fit: cover</code> sizing.</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.container {
    display: flex;
    flex-direction: row;
    width: 100%;
  }
  .test {
    flex: 1;
    margin-right: 1rem;
    overflow: hidden;
    height: 400px;
  }
  img {
    object-fit: cover;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="container"&gt;
    &lt;div class="test"&gt;&lt;img src="http://placehold.it/1920x1080"&gt;&lt;/div&gt;
    &lt;div class="test"&gt;&lt;img src="http://placehold.it/1920x1080"&gt;&lt;/div&gt;
    &lt;div class="test"&gt;&lt;img src="http://placehold.it/1920x1080"&gt;&lt;/div&gt;
    &lt;div class="test"&gt;&lt;img src="http://placehold.it/1920x1080"&gt;&lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>The images are not resizing, as can be seen in <a href="http://codepen.io/harangue/pen/bpzJxO" rel="noreferrer">this demo</a>. Why is that?</p>