Add version-dependent tests for negative years in Dates and DateTimes

README.md

@@ -725,12 +725,19 @@ config :rdf,
 
 
 
+## Caveats
+
+The `Date` and `DateTime` modules of Elixir versions < 1.7.2 don't handle negative years properly. In case you're data contains negative years in `xsd:date` or `xsd:dateTime` literals, you'll have to upgrade to a newer Elixir version.
+
+
+
 ## Getting help
 
 - [Documentation](http://hexdocs.pm/rdf)
 - [Google Group](https://groups.google.com/d/forum/rdfex)
 
 
+
 ## TODO
 
 There's still much to do for a complete RDF ecosystem for Elixir, which means there are plenty of opportunities for you to contribute. Here are some suggestions:
@@ -744,11 +751,13 @@ There's still much to do for a complete RDF ecosystem for Elixir, which means th
 - improve documentation
 
 
+
 ## Contributing
 
 see [CONTRIBUTING](CONTRIBUTING.md) for details.
 
 
+
 ## License and Copyright
 
 (c) 2017-2018 Marcel Otto. MIT Licensed, see [LICENSE](LICENSE.md) for details.

test/unit/datatypes/date_test.exs

@@ -10,8 +10,8 @@ defmodule RDF.DateTest do
       "2010-01-01+01:00" => { {~D[2010-01-01], "+01:00"} , nil                , "2010-01-01+01:00" },
       "2009-12-31-01:00" => { {~D[2009-12-31], "-01:00"} , nil                , "2009-12-31-01:00" },
       "2014-09-01-08:00" => { {~D[2014-09-01], "-08:00"} , nil                , "2014-09-01-08:00" },
-# TODO: DateTime doesn't support negative years (at least with the iso8601 conversion functions)
+# TODO: Dates on Elixir versions < 1.7.2 don't handle negative years correctly, so we test this conditionally below
-#      "-2010-01-01Z"     => {  ~D[-2010-01-01]           , nil                , "-2010-01-01Z"     },
+#      "-2010-01-01Z"     => { {~D[-2010-01-01], "Z"}     , nil                , "-2010-01-01Z"     },
     },
     invalid: ~w(
         foo
@@ -25,6 +25,28 @@ defmodule RDF.DateTest do
       ) ++ [true, false, 2010, 3.14, "2010-01-01Z foo", "foo 2010-01-01Z"]
 
 
+  unless Version.compare(System.version(), "1.7.2") == :lt do
+    test "negative years" do
+      assert Date.new("-2010-01-01Z") ==
+               %Literal{value: {~D[-2010-01-01], "Z"}, uncanonical_lexical: nil, datatype: RDF.NS.XSD.date, language: nil}
+      assert (Date.new("-2010-01-01Z") |> Literal.lexical) == "-2010-01-01Z"
+      assert (Date.new("-2010-01-01Z") |> Literal.canonical) == Date.new("-2010-01-01Z")
+      assert Literal.valid? Date.new("-2010-01-01Z")
+
+      assert Date.new("-2010-01-01") ==
+               %Literal{value: ~D[-2010-01-01], uncanonical_lexical: nil, datatype: RDF.NS.XSD.date, language: nil}
+      assert (Date.new("-2010-01-01") |> Literal.lexical) == "-2010-01-01"
+      assert (Date.new("-2010-01-01") |> Literal.canonical) == Date.new("-2010-01-01")
+      assert Literal.valid? Date.new("-2010-01-01")
+
+      assert Date.new("-2010-01-01+00:00") ==
+               %Literal{value: {~D[-2010-01-01], "Z"}, uncanonical_lexical: "-2010-01-01+00:00", datatype: RDF.NS.XSD.date, language: nil}
+      assert (Date.new("-2010-01-01+00:00") |> Literal.lexical) == "-2010-01-01+00:00"
+      assert (Date.new("-2010-01-01+00:00") |> Literal.canonical) == Date.new("-2010-01-01Z")
+      assert Literal.valid? Date.new("-2010-01-01+00:00")
+    end
+  end
+
   describe "equality" do
     test "two literals are equal when they have the same datatype and lexical form" do
       [

test/unit/datatypes/date_time_test.exs

@@ -22,8 +22,8 @@ defmodule RDF.DateTimeTest do
       "2009-12-31T23:00:00-01:00"        => { dt( "2010-01-01T00:00:00Z")        , "2009-12-31T23:00:00-01:00", "2010-01-01T00:00:00Z" },
       "2009-12-31T24:00:00"              => { dt( "2010-01-01T00:00:00")         , "2009-12-31T24:00:00"      , "2010-01-01T00:00:00"  },
       "2009-12-31T24:00:00+00:00"        => { dt( "2010-01-01T00:00:00Z")        , "2009-12-31T24:00:00+00:00", "2010-01-01T00:00:00Z" },
-# TODO: DateTime doesn't support negative years (at least with the iso8601 conversion functions)
+# TODO: DateTimes on Elixir versions < 1.7.2 don't handle negative years correctly, so we test this conditionally below
-#      "-2010-01-01T00:00:00Z"         => { dt("-2010-01-01T00:00:00Z") , nil, "-2010-01-01T00:00:00Z" },
+#      "-2010-01-01T00:00:00Z"            => { dt("-2010-01-01T00:00:00Z")        , nil, "-2010-01-01T00:00:00Z" },
     },
     invalid: ~w(
         foo
@@ -37,6 +37,23 @@ defmodule RDF.DateTimeTest do
         2010_
       ) ++ [true, false, 2010, 3.14, "2010-01-01T00:00:00Z foo", "foo 2010-01-01T00:00:00Z"]
 
+  unless Version.compare(System.version(), "1.7.2") == :lt do
+    test "negative years" do
+      assert DateTime.new("-2010-01-01T00:00:00Z") ==
+               %Literal{value: dt("-2010-01-01T00:00:00Z"), uncanonical_lexical: nil, datatype: RDF.NS.XSD.dateTime, language: nil}
+      assert (DateTime.new("-2010-01-01T00:00:00Z") |> Literal.lexical) == "-2010-01-01T00:00:00Z"
+      assert (DateTime.new("-2010-01-01T00:00:00Z") |> Literal.canonical) ==
+               DateTime.new("-2010-01-01T00:00:00Z")
+      assert Literal.valid? DateTime.new("-2010-01-01T00:00:00Z")
+
+      assert DateTime.new("-2010-01-01T00:00:00+00:00") ==
+               %Literal{value: dt("-2010-01-01T00:00:00Z"), uncanonical_lexical: "-2010-01-01T00:00:00+00:00", datatype: RDF.NS.XSD.dateTime, language: nil}
+      assert (DateTime.new("-2010-01-01T00:00:00+00:00") |> Literal.lexical) == "-2010-01-01T00:00:00+00:00"
+      assert (DateTime.new("-2010-01-01T00:00:00+00:00") |> Literal.canonical) ==
+               DateTime.new("-2010-01-01T00:00:00Z")
+      assert Literal.valid? DateTime.new("-2010-01-01T00:00:00+00:00")
+    end
+  end
 
   describe "equality" do
     test "two literals are equal when they have the same datatype and lexical form" do