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:
self.data_values = data_to_cache
// generate a hash of values to return
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.