Specs for XML parser errors.

lib/oga/xml/parser.y

@@ -206,7 +206,7 @@ end
       end
     end
 
-    raise Racc::ParseError, <<-EOF
+    raise Racc::ParseError, <<-EOF.strip
 Unexpected #{name} with value #{value.inspect} on line #{@line}:
 
 #{lines}

spec/oga/xml/parser/error_spec.rb

@@ -0,0 +1,33 @@
+require 'spec_helper'
+
+describe Oga::XML::Parser do
+  context 'raising syntax errors' do
+    before do
+      @invalid_xml = <<-EOF.strip
+<person>
+  <name>Alice</name>
+  <age>25
+  <nationality>Dutch</nationality>
+</person>
+      EOF
+    end
+
+    example 'raise a Racc::ParseError' do
+      expect { parse(@invalid_xml) }.to raise_error(Racc::ParseError)
+    end
+
+    example 'display a more meaningful error message' do
+      # Racc basically reports errors at the last moment instead of where they
+      # *actually* occur.
+      partial = <<-EOF.strip
+   1. <person>
+   2. <name>Alice</name>
+   3. <age>25
+   4. <nationality>Dutch</nationality>
+=> 5. </person>
+      EOF
+
+      parse_error(@invalid_xml).should =~ /#{partial}/
+    end
+  end
+end

spec/support/parsing.rb

@@ -41,5 +41,17 @@ module Oga
     def parse_html(input, options = {})
       return Oga::HTML::Parser.new(options).parse(input)
     end
+
+    ##
+    # Parses the given invalid XML and returns the error message.
+    #
+    # @param [String] xml
+    # @return [String]
+    #
+    def parse_error(xml)
+      parse(xml)
+    rescue Racc::ParseError => error
+      return error.message
+    end
   end # ParsingHelpers
 end # Oga