rspec The expect syntax does not support operator matchers, so you must pass a matcher to `#to`

Question

using the new expect syntax:

 expect(@line.filter_results_and_display_them).to == @processed

Getting this error:

ArgumentError: The expect syntax does not support operator matchers, so you must pass a matcher to '#to'

Answer 1

This syntax works:

expect(@line.filter_results_and_display_them).to eq @processed