My plugin is added to the config, but its middleware is never called

Some plugins are order-dependent.

For example, CanHaveConnectedSteps has a middleware for the instance result method in the Standard config.

middlewares :result do
  # ...
  use Plugins::Service::CanHaveConnectedSteps::Middleware
  # ...
end

If your plugin enhances the instance result method as well, you may be affected by CanHaveConnectedSteps.

How? Let's check its source.

module ConvenientService
  module Service
    module Plugins
      module CanHaveConnectedSteps
        class Middleware < Core::MethodChainMiddleware
          def next(...)
            return chain.next(...) if entity.steps.none?
            # ...
            entity.steps.result
          end
          # ...
        end
      end
    end
  end
end

It works as a proxy middleware.

When a service has no steps, CanHaveConnectedSteps just calls what is next in the middleware chain, by chain.next(...).

Otherwise, it returns the last completed step result.

Let's place, e.g. HasJSendResultParamsValidations::UsingActiveModelValidations plugin after CanHaveConnectedSteps in your application service config.

module ApplicationService
  module Config
    include ConvenientService::Concern

    included do
      include ConvenientService::Standard::Config
      # ...
      middlewares :result do
        use ConvenientService::Plugins::Service::HasJSendResultParamsValidations::UsingActiveModelValidations::Middleware
      end
    end
  end
end

This way HasJSendResultParamsValidations::UsingActiveModelValidations is never called for services with steps.

To fix that, locate it before CanHaveConnectedSteps like so:

module ApplicationService
  module Config
    include ConvenientService::Concern

    included do |service_class|
      service_class.class_exec do
        include ConvenientService::Standard::Config
        # ...
        middlewares :result do
          insert_before \
            ConvenientService::Plugins::Service::CanHaveConnectedSteps::Middleware,
            ConvenientService::Plugins::Service::HasJSendResultParamsValidations::UsingActiveModelValidations::Middleware
        end
      end
    end
  end
end

Apart from insert_before, insert_after, insert_after_each, insert_before_each, replace, and delete are also available.