gistfile1.js

let testTree = require('react-test-tree');

class LoginPage extends React.Component {
    render() {
        return (
            <form className="LoginPage">
                <input type="email" ref="email" value={this.state.email} />
                <input type="password" ref="password" value={this.state.password} />
                <input type="submit" ref="login" value="Login" />
            </form>
        );
    }
}

let page = testTree(<LoginPage />);

expect(page.email.value).to.equal("foo@bar.com");

page.email.value = "bar@baz.com";
page.password.value = "password";
page.login.click();