Fix issue with unit tests for Xcrysden

TODO.rst

@@ -16,3 +16,5 @@ TODO List
 #. ecut is not reported in the GSR file.
 
 #. Move unit conversion to NetcdfReader e.g reader.read_value(varname, unit=None)
+
+#. Write new unit tests for Xcrysden and the other visualizers (move these tools to pymatgen?)

abipy/core/testing.py

@@ -26,6 +26,12 @@ class AbipyTest(TestCase):
     def assert_equal(actual, desired, err_msg='', verbose=True):
         return nptu.assert_equal(actual, desired, err_msg=err_msg, verbose=verbose)
 
+    @staticmethod
+    def which(program):
+        """Returns full path to a executable. None if not found or not executable."""
+        from pymatgen.util.io_utils import which
+        return which(program)
+
 
 class AbipyFileTest(AbipyTest):
     """

abipy/core/tests/test_density.py

@@ -35,9 +35,10 @@ class TestDensity(AbipyTest):
             self.assert_almost_equal(nelect_calc, nelect_file)
             self.assert_almost_equal(rhog_tot[0,0,0] * structure.volume, nelect_file)
 
-            # Export data in xsf format.
-            visu = den.export(".xsf")
-            self.assertTrue(callable(visu))
+            if self.which("xcrysden") is not None:
+                # Export data in xsf format.
+                visu = den.export(".xsf")
+                self.assertTrue(callable(visu))
 
 
 if __name__ == "__main__":

abipy/core/tests/test_structure.py

@@ -24,8 +24,9 @@ class TestStructure(AbipyTest):
             # Call pymatgen machinery to get the high-symmetry stars.
             print(structure.hsym_stars)
 
-            # Export data in Xcrysden format.
-            structure.export(".xsf")
+            if self.which("xcrysden") is not None:
+                # Export data in Xcrysden format.
+                structure.export(".xsf")
 
 
 if __name__ == "__main__":

abipy/waves/tests/test_wfkfile.py

@@ -37,7 +37,8 @@ class TestWFKFile(AbipyTest):
             same_ug = wave.gsphere.fromfftmesh(wave.mesh, ug_mesh)
             self.assert_almost_equal(wave.ug, same_ug)
 
-            wave.export_ur2(".xsf", structure)
+            if self.which("xcrysden") is not None:
+                wave.export_ur2(".xsf", structure)
 
             #print wave.ug.shape, same_ug.shape
             #for idx, g in enumerate(wave.gvecs):