While assert_select is flexible and powerful (having many more options than the ones shown here), experience shows that it’s wise to take a lightweight approach by testing only HTML elements (such as site layout links) that are unlikely to change much over time.
Code Matching HTML
assert_select "div" <div>foobar</div>
assert_select "div", "foobar" <div>foobar</div>
assert_select "div.nav" <div class="nav">foobar</div>
assert_select "div#profile" <div id="profile">foobar</div>
assert_select "div[name=yo]" <div name="yo">hey</div>
assert_select "a[href=?]", ’/’, count: 1 <a href="/">foo</a>
assert_select "a[href=?]", ’/’, text: "foo" <a href="/">foo</a>