In some very specific cases, floating-point storage inaccuracy causes :formatted_value to return an unexpected value; specifically, when 57% is stored as a 0%-formatted percentage, :formatted_value returns 56%. Ultimately, this is because the formatter implementation truncates instead of rounding:
Kernel.format('%d%%', number.to_f * 100)
In this specific case, 57% is stored as 0.56999999999999995. Multiplied by 100, that's 56.999999999999995. The %d token truncates that to 56%, whereas %.0f would correctly round to 57%.
PR coming momentarily!
Steps to reproduce
See Gist at https://gist.github.com/leboshi/e0e6302b50eaef325744087048f16924; download and run self-contained (plus XLSX) test script.
Issue
In some very specific cases, floating-point storage inaccuracy causes
:formatted_valueto return an unexpected value; specifically, when57%is stored as a0%-formatted percentage,:formatted_valuereturns56%. Ultimately, this is because the formatter implementation truncates instead of rounding:In this specific case, 57% is stored as 0.56999999999999995. Multiplied by 100, that's 56.999999999999995. The
%dtoken truncates that to 56%, whereas%.0fwould correctly round to 57%.(Possibly related to issue #384?)
System configuration
Roo version: 2.8.3
Ruby version: 2.7.2