Fix new and new! on RDF.Literal and RDF.String when language nil given

lib/rdf/datatypes/string.ex

@@ -5,13 +5,19 @@ defmodule RDF.String do
 
   use RDF.Datatype, id: RDF.Datatype.NS.XSD.string
 
-  def new(value, opts) when is_list(opts), do: new(value, Map.new(opts))
-  def new(value, %{language: _} = opts), do: RDF.LangString.new!(value, opts)
-  def new(value, opts), do: super(value, opts)
+  def new(value, opts) when is_list(opts),
+    do: new(value, Map.new(opts))
+  def new(value, %{language: language} = opts) when not is_nil(language),
+    do: RDF.LangString.new!(value, opts)
+  def new(value, opts),
+    do: super(value, opts)
 
-  def new!(value, opts) when is_list(opts), do: new!(value, Map.new(opts))
-  def new!(value, %{language: _} = opts), do: RDF.LangString.new!(value, opts)
-  def new!(value, opts), do: super(value, opts)
+  def new!(value, opts) when is_list(opts),
+    do: new!(value, Map.new(opts))
+  def new!(value, %{language: language} = opts) when not is_nil(language),
+    do: RDF.LangString.new!(value, opts)
+  def new!(value, opts),
+    do: super(value, opts)
 
 
   def build_literal_by_lexical(lexical, opts) do

lib/rdf/literal.ex

@@ -67,7 +67,10 @@ defmodule RDF.Literal do
   def new(value, opts) when is_list(opts),
     do: new(value, Map.new(opts))
 
-  def new(value, %{language: language} = opts) when not is_nil(language) do
+  def new(value, %{language: nil} = opts),
+    do: new(value, Map.delete(opts, :language))
+
+  def new(value, %{language: language} = opts) do
     if is_binary(value) do
       if opts[:datatype] in [nil, @lang_string] do
         RDF.LangString.new(value, opts)

test/unit/datatypes/string_test.exs

@@ -17,6 +17,14 @@ defmodule RDF.StringTest do
       assert RDF.String.new("foo", language: "en") ==
              RDF.LangString.new("foo", language: "en")
     end
+
+    test "nil as language is ignored" do
+      assert RDF.String.new("Eule", datatype: XSD.string, language: nil) ==
+             RDF.String.new("Eule", datatype: XSD.string)
+      assert RDF.String.new("Eule", language: nil) ==
+             RDF.String.new("Eule")
+    end
+
   end
 
   describe "new!" do
@@ -24,6 +32,14 @@ defmodule RDF.StringTest do
       assert RDF.String.new!("foo", language: "en") ==
              RDF.LangString.new!("foo", language: "en")
     end
+
+    test "nil as language is ignored" do
+      assert RDF.String.new!("Eule", datatype: XSD.string, language: nil) ==
+             RDF.String.new!("Eule", datatype: XSD.string)
+      assert RDF.String.new!("Eule", language: nil) ==
+             RDF.String.new!("Eule")
+    end
+
   end
 
 end

test/unit/literal_test.exs

@@ -91,6 +91,18 @@ defmodule RDF.LiteralTest do
       end
     end
 
+    test "nil as language is ignored" do
+      assert Literal.new("Eule", datatype: XSD.string, language: nil) ==
+             Literal.new("Eule", datatype: XSD.string)
+      assert Literal.new("Eule", language: nil) ==
+             Literal.new("Eule")
+
+      assert Literal.new!("Eule", datatype: XSD.string, language: nil) ==
+             Literal.new!("Eule", datatype: XSD.string)
+      assert Literal.new!("Eule", language: nil) ==
+             Literal.new!("Eule")
+    end
+
     test "construction of a rdf:langString works, but results in an invalid literal" do
       assert %Literal{value: "Eule"} = literal = Literal.new("Eule", datatype: RDF.langString)
       refute Literal.valid?(literal)