Assert the error the control panel login form shows after a failed login.
Examples
Then I should see the login error "Invalid username or password."
Then I should see the login error "Password should contain at least 6 characters."
Then we should see the login error "Invalid username or password."
And I should see the login error "Invalid username"
Then I should see the login error "at least 6 characters"
Pattern
Then(/^(I |we )*should see the login error "([^"]*)"$/, …)
Part of @webship-js/craft-cms-steps (github.com/webship/craft-cms-steps), a step pack for Webship-js 2.0.x.