It's very easy to forget to add `require 'rails_helper'` at the top of every core/plugin spec file, and omissions can cause some very confusing/sporadic errors.
By setting this flag in `.rspec`, we can remove the need for `require 'rails_helper'` entirely.
Previously calls such as `Emoji["smile"]` would force a full dehydration of
objects from Redis.
This introduces a version safe site and global emoji cache so lookups are
cheap. It eliminates iterating through the list of emojis and pulling from
redis.
Distributed cache uses a normalized name as the key and stores an Array tuple
with version and Emoji. Successful hits always confirm version matches.
Interface to Emoji object remains unchanged.
We opted for 2 caches to improve reuse on multisites. misses though will be
stored in both caches. If there is a hit on the global cache we can avoid
looking up in site local cache and storing a miss there.
This change both speeds up specs (less strings to allocate) and helps catch
cases where methods in Discourse are mutating inputs.
Overall we will be migrating everything to use #frozen_string_literal: true
it will take a while, but this is the first and safest move in this direction
