lib/si/module.rb in si-0.1.2 vs lib/si/module.rb in si-0.1.3

@@ -1,13 +1,16 @@
 module SI
   class << self
     def convert num, options = {}
-      options = { :length => options } if options.is_a?(Fixnum) && options >= 3
+      options = { :length => options } if options.is_a?(Fixnum)
       options = DEFAULT.merge(options)
       length,
       min_exp,
       max_exp = options.values_at(:length, :min_exp, :max_exp)
+      raise ArgumentError.new("Invalid length") if length < 2
+      return num.is_a?(Fixnum) ? '0' : "0.#{'0' * (length - 1)}" if num == 0
+
       base    = options[:base].to_f
       minus   = num < 0 ? '-' : ''
       nump    = num.abs
 
       PREFIXES.keys.sort.reverse.select { |exp| (min_exp..max_exp).include? exp }.each do |exp|
@@ -25,10 +28,9 @@
       nil
     end
 
     def revert str, options = {}
       options = DEFAULT.select { |k, v| k == :base }.merge(options)
-      base    = options[:base]
       pair    = PREFIXES.to_a.find { |k, v| v == str[-1] }
 
       if pair
         str[0...-1].to_f * (options[:base] ** pair.first)
       else