Fix the case when using order_by_function with Solr strdist

sunspot/lib/sunspot/query/sort.rb

@@ -134,6 +134,23 @@ class FunctionComp
  def initialize(setup,args)
  @function=args.shift
  @fields = []
+ @extras = []
+
+ case @function.to_s
+ when "strdist"
+ # Reference: http://wiki.apache.org/solr/FunctionQuery#strdist
+ valid_measures = [:jw, :edit, :ngram]
+ extra = args.pop
+ if valid_measures.include? extra.to_sym
+ @extras.push(extra)
+ else
+ raise(
+ UnrecognizedRestrictionError,
+ "Use only valid measure options with strdist (#{valid_measures.to_s})"
+ )
+ end
+ end
+
  args.each do |argument|
  case argument.class.name
  when "Array"
@@ -146,7 +163,9 @@ def initialize(setup,args)
  end
  end
  def to_s
- "#{function}(#{fields.map(&:to_s).join(",")})"
+ mapped_fields = fields
+ mapped_fields = mapped_fields + @extras if not @extras.empty?
+ "#{function}(#{mapped_fields.map(&:to_s).join(",")})"
  end
  end
  end

sunspot/spec/integration/scoped_search_spec.rb

@@ -461,8 +461,8 @@ def self.test_field_type(name, attribute, field, *values)
  describe 'ordering by function' do
  before :all do
  Sunspot.remove_all
- @p1 = Post.new(:blog_id => 1, :category_ids => [3])
- @p2 = Post.new(:blog_id => 2, :category_ids => [1])
+ @p1 = Post.new(:title => 'Post Test', :blog_id => 1, :category_ids => [3])
+ @p2 = Post.new(:title => 'Test', :blog_id => 2, :category_ids => [1])
  Sunspot.index([@p1,@p2])
  Sunspot.commit
  end
@@ -486,5 +486,19 @@ def self.test_field_type(name, attribute, field, *values)
  search = Sunspot.search(Post) {order_by_function :product, :blog_id, -2, :desc}
  search.results.first.should == @p1
  end
+ context 'when ordering by strdist' do
+ # Reference: http://wiki.apache.org/solr/FunctionQuery#strdist
+ it 'should only accept valid values as measures' do
+ [:jw, :edit, :ngram].each do |measure|
+ search = Sunspot.search(Post) {order_by_function :strdist, :title, "'Test'", measure, :desc}
+ search.results.first.should == @p2
+ end
+ end
+ it 'should not accept invalid values as measures' do
+ lambda do
+ Sunspot.search(Post) {order_by_function :strdist, :title, "'Test'", :wrong_measure, :desc}
+ end.should raise_error(Sunspot::UnrecognizedRestrictionError)
+ end
+ end
  end
 end