Array#sort and #sort! documentation issue
The documentation about the values that should be returned by the block is backwards.
a <=> b will return -1 if a is lower than b, i.e. b follows a (in the sorted array).
a <=> b will return 1 if a is greater than b, i.e. a follows b (in the sorted array).
Using the "follows" verbal form might not be the best choice here, but I'd rather let a native english speaker rephrase it if needed.
This part of the documentation is backwards since the 2.0.0 release (commit 53b61ccb).