Add simple test for Pdf export

Author: ales-erjavec

Orange/widgets/tests/test_io.py

@@ -0,0 +1,20 @@
+import os
+import tempfile
+import unittest
+
+from AnyQt.QtWidgets import QGraphicsScene, QGraphicsRectItem
+from Orange.widgets.tests.base import GuiTest
+
+from Orange.widgets import io as imgio
+
+@unittest.skipUnless(hasattr(imgio, "PdfFormat"), "QPdfWriter not available")
+class TestIO(GuiTest):
+    def test_pdf(self):
+        sc = QGraphicsScene()
+        sc.addItem(QGraphicsRectItem(0, 0, 20, 20))
+        fd, fname = tempfile.mkstemp()
+        os.close(fd)
+        try:
+            imgio.PdfFormat.write_image(fname, sc)
+        finally:
+            os.unlink(fname)