Ruby on Rails

We have a Lockable concern that allows for locks via Redis

module Lockable    extend ActiveSupport::Concern      def redis_lock(key, options = {})      Redis::Lock.new(        key,        expiration: options[:expiration] || 15,        timeout: options[:timeout] || 0.1      ).lock { yield if block_given? }    end  end

We use this in a Controller method to ensure concurrent requests are handled correctly.

def create    redis_lock(<generated_key>, timeout: 15) do      # perform_operation    end      render json: <data>, status: :ok  end

When testing this action, I want to test that the correct generated_key is being sent to Redis to initiate a lock.

I set up an expect for the Redis::Lock but that returns false always presumably because the request to create is sent mid request and not at the end of it.

expect(Redis::Lock).to receive(:create).once

Since the lock is cleared at the end of the method call, I cannot check for the key in redis as a test.

This answer recommends setting up a fake class that matches the structure of Lockable to emulate the same behaviour but how do I write a test for it? The method we have does not return any value to verify.

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