Merge b5ebfbf into 303f90f

CHANGELOG.md

@@ -1,4 +1,5 @@
 # [develop](https://github.com/benlangfeld/ruby_speech)
+  * Bugfix: Rulerefs referenced n-levels deep under Rulerefs should be expanded.
 
 # [2.3.2](https://github.com/benlangfeld/ruby_speech/compare/v2.3.1...v2.3.2) - [2014-04-21](https://rubygems.org/gems/ruby_speech/versions/2.3.2)
   * Bugfix: String nodes should take non-strings and cast to a string (`#to_s`)

lib/ruby_speech/grxml/grammar.rb

@@ -32,6 +32,7 @@ class Grammar < Element
       self.defaults = { :version => '1.0', :language => "en-US", namespace: GRXML_NAMESPACE }
 
       VALID_CHILD_TYPES = [Nokogiri::XML::Element, Nokogiri::XML::Text, Rule, Tag].freeze
+      MAX_RULE_NESTING_DEFAULT = 25.freeze
 
       ##
       #
@@ -116,9 +117,19 @@ def inline
       # @return self
       #
       def inline!
-        xpath("//ns:ruleref", :ns => GRXML_NAMESPACE).each do |ref|
-          rule = rule_with_id ref[:uri].sub(/^#/, '')
-          ref.swap rule.dup.children
+        (self.class.max_rule_nesting + 1).times do |i|
+          rule = nil
+          j = 0
+          xpath("//ns:ruleref", :ns => GRXML_NAMESPACE).each do |ref|
+            if ([i,j].max + 1) > self.class.max_rule_nesting
+              raise ArgumentError, "Max ruleref recursion level of #{self.class.max_rule_nesting} has been exceeded."
+            end
+            rule = rule_with_id ref[:uri].sub(/^#/, '')
+            raise ArgumentError, "The Ruleref \"#{ref[:uri]}\" is referenced but not defined" unless rule
+            ref.swap rule.dup.children
+            j += 1
+          end
+          break unless rule
         end
 
         query = "./ns:rule[@id!='#{root}']"
@@ -185,6 +196,10 @@ def embed(other)
 
       private
 
+      def self.max_rule_nesting
+        (ENV['RUBYSPEECH_MAX_RULE_NESTING'] || MAX_RULE_NESTING_DEFAULT).to_i
+      end
+
       def has_matching_root_rule?
         !root || root_rule
       end

spec/ruby_speech/grxml/grammar_spec.rb

@@ -232,6 +232,111 @@ module GRXML
           grammar.inline!.should == inline_grammar
           grammar.should == inline_grammar
         end
+
+        context 'nested' do
+          context 'in a self-referencial infinite loop' do
+            subject do
+              RubySpeech::GRXML.draw mode: :dtmf, root: 'main' do
+                rule :id => :main, :scope => 'public' do
+                  ruleref uri: '#paradox'
+                end
+                rule id: 'paradox' do
+                  ruleref uri: '#paradox'
+                end
+              end
+            end
+
+            it 'should be rejected with an error' do
+              expect { subject.inline }.to raise_error ArgumentError, /Max ruleref recursion level of 25 has been exceeded./
+            end
+          end
+
+          context 'with an invalid-reference' do
+            subject do
+              RubySpeech::GRXML.draw mode: :dtmf, root: 'main' do
+                rule :id => :main, :scope => 'public' do
+                  ruleref uri: '#lost'
+                end
+              end.inline
+            end
+
+            it 'should raise a descriptive exception' do
+              expect { subject }.to raise_error ArgumentError, 'The Ruleref "#lost" is referenced but not defined'
+            end
+          end
+
+          context 'deeply' do
+            before :each do
+              subject.root = 'main'
+              subject << Rule.new(doc, :id => 'main', :scope => 'public') do
+                ruleref uri: '#level0'
+              end
+
+              levels.times do |i|
+                next_ref = i + 1
+                subject << if next_ref < levels
+                   Rule.new(doc, :id => "level#{i}") do
+                    ruleref uri: "#level#{next_ref}"
+                  end
+                else
+                  Rule.new(doc, :id => "level#{i}") do
+                    string "How about an oatmeal cookie?  You'll feel better."
+                  end
+                end
+              end
+            end
+
+            after :each do
+              ENV['RUBYSPEECH_MAX_RULE_NESTING'] = nil
+            end
+
+            let :expected_doc do
+              RubySpeech::GRXML.draw root: 'main' do
+                rule :id => :main, :scope => 'public' do
+                  string "How about an oatmeal cookie?  You'll feel better."
+                end
+              end
+            end
+
+            context '25 levels deep' do
+              let(:levels) { 25 }
+
+              it 'should equal the expected doc' do
+                expect(subject.inline).to eq expected_doc
+              end
+            end
+
+            context '26 levels deep' do
+              let(:levels) { 26 }
+
+              it 'should be rejected with an error' do
+                expect { subject.inline }.to raise_error ArgumentError, /Max ruleref recursion level of 25 has been exceeded./
+              end
+            end
+
+            context 'with RUBYSPEECH_MAX_RULE_NESTING=100' do
+              before :each do
+                ENV['RUBYSPEECH_MAX_RULE_NESTING'] = '100'
+              end
+
+              context '100 levels deep' do
+                let(:levels) { 100 }
+
+                it 'should equal the expected doc' do
+                  expect(subject.inline).to eq expected_doc
+                end
+              end
+
+              context '101 levels deep' do
+                let(:levels) { 101 }
+
+                it 'should be rejected with an error' do
+                  expect { subject.inline }.to raise_error ArgumentError, /Max ruleref recursion level of 100 has been exceeded./
+                end
+              end
+            end
+          end
+        end
       end
 
       describe "#tokenize!" do