Unit not recognized error after 4.0.0 upgrade

[smathieu]

We had some definitions that worked with the 3.0.0 release that are now failing after the upgrade.

Here's a short script to reproduce the issue:

require "ruby-units"

Unit.define("m2") do |u|
  u.definition = Unit.new("1 m") * Unit.new("1 m")
  u.display_name = "m^2"
  u.aliases = ["m²", "square_meter"]
end

puts Unit.new("1 m2") # => 1 m^2
puts Unit.new("1 square_meter") # => raise(ArgumentError, "'#{passed_unit_string}' Unit not recognized") unless used.empty?

This works in the 3.0.0 release, but raises an exception in the latest release. This does not seem to be an intended change.

[olbrich]

I think the problem here is the _ in the alias name. The parsing algorithm strips those out so that numbers can be passed in like 1_000_000, but it also impacts the unit name. I'll look into making that a little more specific so that it only strips out underscores in numbers, but you might be able to use a - instead in the meantime.

See

ruby-units/lib/ruby_units/unit.rb

Line 1584 in e90fc78

unit_string.gsub!(/[%'"#_,]/, '%' => 'percent', "'" => 'feet', '"' => 'inch', '#' => 'pound', '_' => '', ',' => '')

[smathieu]

Thanks for the quick response! This isn't super urgent, but is preventing us from updating. The square_meter strings comes from an external API, so we can't control this.

[olbrich]

@smathieu can you please verify if the branch associated with #331 fixes your issue?