Then the page generator should start with "Gatsby"

Assert what the page's generator meta tag says: the whole content ("be"), its start ("start with") or a part of it ("contain"), without regard to case. The name of the generator is a value of the step, so the same step tells a page of this site from a page another tool made.

Examples

Then the page generator should start with "Gatsby"
And the page generator should be "Gatsby 5.16.1"
And the page generator should contain "5.16"
But the page generator should not start with "Hugo"
Then page generator should start with "Gatsby 5"

Pattern

Then(/^(?:the )?page generator should( not)* (be|start with|contain) "([^"]*)"$/, …)

Part of @webship-js/gatsby-steps (github.com/webship/gatsby-steps), a step pack for Webship-js 2.0.x.