Writing tests with RSpec for Redis with Rails
capybara, redis, rspec, ruby, ruby-on-rails
Solution
I like to have redis running while the tests are running. Redis, unlike e.g. postgres, is extremely fast and doesn't slow down test run time noticeably.
Just make sure you call `REDIS.flush` in a `before(:each)` block, or the corresponding cucumber hook.
You can test `data_to_cache` independently of redis, but unless you can fully trust the redis driver you're using and the contract it provides, it's safer to actually test `cache_data` (and the corresponding cache fetch method) live. That also allows you to switch to a different redis driver (or to a different fast KV store) without a wholesale rewrite of your tests.
Problem
I have a model class that caches data in redis. The first time I call a method on the model, it computes a JSON/Hash value and stores it in Redis. Under certain circumstances I 'flush' that data and it gets recomputed on the next call. Here's the code snippet similar to the one I use to store the data in Redis: ``` def cache_data self.data_values = data_to_cache REDIS.set(redis_key,ActiveSupport::JSON.encode(self.data_values)) REDIS.get(redis_key) end def data_to_cache # generate a hash of values to return end ``` How should I unit test this code? I use RSpec and Capybara. I also use Cucumber and Capabara for integration testing if that helps.