Assert the cookie banner shows (or does not show) exactly this text, compared after collapsing whitespace.
Examples
Then the cookie banner should say "We use cookies to improve your experience."
And the cookie banner should say "This site uses cookies."
And the cookie banner should say "Cookies help us run the site."
But the cookie banner should not say "We sell your data."
Then cookie banner should say "Accept our cookies?"
Pattern
Then(/^(?:the )?cookie banner should( not)* say "([^"]*)"$/, …)
Part of @webship-js/squarespace-steps (github.com/webship/squarespace-steps), a step pack for Webship-js 2.0.x.