The wrong types of exceptions are being raised

[ajvondrak]

In places like

mock_redis_lua_extension/lib/mock_redis_lua_extension.rb

Line 77 in ce41d51

raise ArgumentError, "NOSCRIPT No matching script. Please use EVAL."

a generic ArgumentError is being raised. However, the actual redis client will raise things like Redis::CommandError (for the NOSCRIPT error at least). You'll notice that the mock_redis gem takes care to raise the same sorts of errors: https://github.com/brigade/mock_redis/search?q=commanderror&unscoped_q=commanderror

As is, I now have to write my code like

begin
  $redis.evalsha(...)
rescue Redis::CommandError, ArgumentError => error # notice the two types of errors here
  raise unless error.message.start_with?('NOSCRIPT')
  $redis.eval(...)
end

Using only one class or the other, either my test suite will break or my real-world code will. So I think it's prudent to go through each raise and determine whether the right type of error is being used.