Dydra.com SPARQL tests

These tests define the Dydra.com SPARQL dialect. They are based heavily on the W3C spec as well as custom tests. They are the best way to determine when and why we deviate from the SPARQL standard.

For every known deviation from a W3C test, the W3C test remains intact alongside, and is tagged with an rspec tag. Thus, not every test in the repository is expected to pass. The failing tests are there for comparison purposes.

To run only the tests that we would expect to pass:

$ bundle install
$ bundle exec rspec -cfn \
    --tag '~reduced:all' \
    --tag '~arithmetic:boxed' \
    --tag '~blank_nodes:unique' \
    --tag '~status:bug' \
    --tag '~tz:zoned' \
    spec/w3c/data-r2/

Known buggy tests are skipped with --tag '~status:bug', to enable them, remove the tag.

Running specs from another project

{SPARQL::Spec} can be required from a project implementing a SPARQL engine by requiring 'sparql/spec' and using with a spec running such as the following:

require File.join(File.dirname(__FILE__), 'spec_helper')
require 'sparql/spec'
require 'rdf/isomorphic'

describe SPARQL::Algebra do
  describe "w3c dawg SPARQL syntax tests" do
    SPARQL::Spec.load_sparql1_0_tests.group_by(&:manifest).each do |man, tests|
      describe man.to_s.split("/")[-2] do
        tests.each do |t|
          it "evaluates #{t.name}" do

            graphs = t.graphs # Hash containing strings for :default and named graphs

            query = t.action.query_string
            expected = t.solutions          # RDF::Query::Solutions, RDF::Graph or boolean, based on form

            result = sparql_query(:graphs => graphs, :query => query, :base_uri => t.action.query_file,
                                  :repository => "sparql-spec", :form => t.form)

            case t.form
            when :select, :create, :describe
              result.should be_isomorphic_with(expected)
            when :ask
              result.should be_true
            end
          end
        end
      end
    end
  end
end

Within spec_helper, define a method sparql_query, taking defined graphs, and query string returning an RDF::Query::Solutions result set. For example:

Known Quirks

The tags above represent our known quirks. W3C tests remain alongside these tests, tagged differently, with the original W3C expectations instead of our adjusted ones.

arithmetic: boxed

This tag marks tests which fail because of normalization of numeric types. Dydra.com treats the literal "01", and many other variables of untyped literals, as a number. Some W3C tests require the store to return the original value, in some cases after doing arithmetic comparisons on it. A SPARQL endpoint passing arithmetic:boxed tests would return the non-normalized numeric values.

blank_nodes:unique

This tag marks tests which have been modified (not necessarily failing) due to Dydra.com's treatment of blank node identifiers as canonical. Tests tagged with blank_nodes:unique would be passed by a SPARQL endpoint that generates new blank node identifiers for each serialization/query/etc.

reduced:all

The REDUCED modifier may or may not reduce all results. The expectations for tests marked reduced:all are not reduced. Dydra.com passes tests which remove duplicates.

values:lexical

Dydra.com treats some input as the lexical representations of their real values. In particular, dates, times, and datetimes are always returned in Zulu time, regardless of their input format. Time zone information is not saved. In the same way, string literal language tags are normalized to a lowercase form.