Assert a plugin is installed, active or inactive, as the Plugins screen lists it. The plugin is named as the screen shows it.
Examples
Then the "Hello Dolly" plugin should be installed
And the "Akismet Anti-spam: Spam Protection" plugin should be inactive
Then the "Hello Dolly" plugin should be active
And the "Some Plugin" plugin should not be installed
Then the "Hello Dolly" plugin should not be active
Pattern
Then(/^the "([^"]*)" plugin should( not)* be (installed|active|inactive)$/, …)
Part of @webship-js/wordpress-steps (github.com/webship/wordpress-steps), a step pack for Webship-js 2.0.x.