Test that size is greater than 0.

workflow/tests/test_plot_profile.py

@@ -11,8 +11,9 @@ test_output_path = os.path.dirname(os.path.abspath(__file__)) + \
 @pytest.mark.singleend
 def test_plot_singleend():
     assert os.path.exists(os.path.join(test_output_path, 'plotProfile.png'))
-
+    assert os.path.getsize(os.path.join(test_output_path, 'plotProfile.png')) > 0
 
 @pytest.mark.pairedend
 def test_plot_pairedend():
-    assert os.path.exists(os.path.join(test_output_path, 'computeMatrix.gz'))
+    assert os.path.exists(os.path.join(test_output_path, 'plotProfile.png'))
+        assert os.path.getsize(os.path.join(test_output_path, 'plotProfile.png')) > 0