Assert one of the site's built-in forms is, or is not, visible, by the data-drupal-selector and the id Form API derives from the form's machine name, whatever the theme. Forms with fields the page is useless without (the login form's username and password, the site information form's site name) additionally require those fields. The contact form is any form of the Contact module, not only the one named "feedback". On a site without the Contact or the Search module the step says so.
Examples
Then I should see the login form
And should see the sign-in form
Then we should see the registration form
And I should see the password reset form
Then we should see the contact us form
And I should not see the login form
Pattern
Then(/^(I |we )*should( not)* see the (login|sign-?in|registration|register|sign[ -]?up|password reset|reset password|forgot password|contact[ -]?us|contact|search|site information) form$/, …)
Part of @webship-js/drupal-cms-steps (github.com/webship/drupal-cms-steps), a step pack for Webship-js 2.0.x.