add test file

not currently used, needs converting to rspec

spec/lib/mittsu/3mf/test_exporter.rb

@@ -0,0 +1,65 @@
+require 'minitest_helper'
+require 'rexml/document'
+require 'rexml/xpath'
+
+class Test3MFExporter < Minitest::Test
+  def setup
+    @box = Mittsu::Mesh.new(
+      Mittsu::BoxGeometry.new(1.0, 1.0, 1.0)
+    )
+    @box.name = "box"
+    @exporter = Mittsu::ThreeMFExporter.new
+  end
+
+  def test_filename_sanitization
+    @box.name = "<box>"
+    name = @exporter.send(:filesystem_safe_name, @box)
+    assert_equal "box", name
+  end
+
+  def test_3mf_model_file
+    file = @exporter.send(:model_file, @box)
+    xml = REXML::Document.new file
+    assert_equal "millimeter", REXML::XPath.first(xml, "/model/@unit").value
+    assert_equal "model", REXML::XPath.first(xml, "/model/resources/object/@type").value
+    assert_equal 8, REXML::XPath.match(xml, "/model/resources/object/mesh/vertices/vertex").count
+    assert_equal 12, REXML::XPath.match(xml, "/model/resources/object/mesh/triangles/triangle").count
+  end
+
+  def test_grouped_meshes
+    group = Mittsu::Group.new
+    group.add(@box)
+    group.add(Mittsu::Mesh.new(Mittsu::SphereGeometry.new()))
+    file = @exporter.send(:model_file, group)
+    xml = REXML::Document.new file
+    assert_equal 2, REXML::XPath.match(xml, "/model/resources/object/mesh").count
+    assert_equal 8, REXML::XPath.match(xml, "/model/resources/object[1]/mesh/vertices/vertex").count
+    assert_equal 12, REXML::XPath.match(xml, "/model/resources/object[1]/mesh/triangles/triangle").count
+    assert_equal 63, REXML::XPath.match(xml, "/model/resources/object[2]/mesh/vertices/vertex").count
+    assert_equal 88, REXML::XPath.match(xml, "/model/resources/object[2]/mesh/triangles/triangle").count
+    assert_equal 2, REXML::XPath.match(xml, "/model/build/item").count
+  end
+
+  def test_content_types_file
+    file = @exporter.send(:content_types_file)
+    xml = REXML::Document.new file
+    assert_equal "application/vnd.openxmlformats-package.relationships+xml",
+      REXML::XPath.first(xml, "/Types/Default[@Extension='rels']/@ContentType").value
+  end
+
+  def test_rels_file
+    file = @exporter.send(:rels_file, ["box"])
+    xml = REXML::Document.new file
+    assert_equal "/3D/box.model",
+      REXML::XPath.first(xml, "/Relationships/Relationship/@Target").value
+  end
+
+  def test_export_method_alias
+    Dir.mktmpdir do |dir|
+      filename = File.join(dir, "test.3mf")
+      @exporter.parse(@box, filename)
+      assert File.exist?(filename)
+    end
+  end
+
+end