increasing test coverage

caught an error!

lib/csvlint/csvw/number_format.rb

@@ -134,7 +134,7 @@ def initialize(pattern=nil, grouping_separator=nil, decimal_separator=".")
                 fractional_regexp += "(#{Regexp.escape(@grouping_separator)}[0-9]{1,#{max_fraction_digits % @fractional_grouping_size}})?" if max_fraction_digits % @fractional_grouping_size > 0
               else
                 fractional_regexp += "([0-9]{#{@fractional_grouping_size}}#{Regexp.escape(@grouping_separator)}){0,#{(max_fraction_digits / @fractional_grouping_size) - 1}}" if max_fraction_digits > @fractional_grouping_size
-                fractional_regexp += "[0-9]{#{@fractional_grouping_size}}"
+                fractional_regexp += "[0-9]{1,#{@fractional_grouping_size}}"
               end
               fractional_regexp = "#{Regexp.escape(@decimal_separator)}#{fractional_regexp}"
               fractional_regexp = "(#{fractional_regexp})?" if min_fraction_digits == 0

spec/csvw/number_format_spec.rb

@@ -300,6 +300,20 @@
     expect(format.parse("12.345,67,8")).to eql(nil)
   end
 
+  it "should parse numbers that match 0.###,### correctly" do
+    format = Csvlint::Csvw::NumberFormat.new("0.###,###")
+    expect(format.parse("1")).to eq(1)
+    expect(format.parse("12.3")).to eql(12.3)
+    expect(format.parse("12.34")).to eql(12.34)
+    expect(format.parse("12.345")).to eq(12.345)
+    expect(format.parse("12.3456")).to eql(nil)
+    expect(format.parse("12.345,6")).to eql(12.3456)
+    expect(format.parse("12.34,56")).to eql(nil)
+    expect(format.parse("12.345,67")).to eq(12.34567)
+    expect(format.parse("12.345,678")).to eql(12.345678)
+    expect(format.parse("12.345,67,8")).to eql(nil)
+  end
+
   it "should parse numbers that match 0.000,### correctly" do
     format = Csvlint::Csvw::NumberFormat.new("0.000,###")
     expect(format.parse("1")).to eq(nil)