This is a Lightning Component to show a Case Close button in Salesforce with input fields in a modal box. Case Close solution using Quick Action do not create Case Comment Record and it is not shown in a modal box like quick actions on other objects. This solution only shows Case Status values which are of Type Closed dynamically using apex in the Status Selection field.
abhimanyud3dx/Close-Case-Lightning-Component
Code sample to close case via custom Lightning button with modal box
JavaScript