Assert a component is, or is not, offered in the Canvas component library, by machine id or visible name. The editor fills its Library from the same endpoint queried here, so this checks what a site builder can place without driving the editor.
Examples
Then the Canvas component library should list the "Heading" component
And the Canvas component library should list the "sdc.mercury.text" component
Then the Canvas component library should not list the "Legacy slider" component
And the Canvas component library should list the "block.system_branding_block" component
Then the Canvas component library should not list the "sdc.old.banner" component
Pattern
Then(/^the Canvas component library should( not)* list the "([^"]*)" component$/, …)
Part of @webship-js/drupal-cms-steps (github.com/webship/drupal-cms-steps), a step pack for Webship-js 2.0.x.