Fix r.fillnulls to run in python 3 (#85)

* Fix r.fillnulls to run in python 3 and update testsuite to cover bspline case as well as run with the NC elevation test dataset.
* Fix r.fillnulls: Use grass.script.decode rather than str.decode and some testsuite touch-ups.

scripts/r.fillnulls/r.fillnulls.py

@@ -473,7 +473,7 @@ def main():
                     flags='n',
                     stderr=subprocess.PIPE,
                     env=new_env)
-                stdout, stderr = p.communicate()
+                stderr = grass.decode(p.communicate()[1])
                 if "No NULL cells found" in stderr:
                     grass.run_command('g.copy', raster='%s,%sfilled' % (input, prefix), overwrite=True)
                     p.returncode = 0
@@ -494,7 +494,7 @@ def main():
                     flags='n',
                     stderr=subprocess.PIPE,
                     env=new_env)
-                stdout, stderr = p.communicate()
+                stderr = grass.decode(p.communicate()[1])
                 if "No NULL cells found" in stderr:
                     grass.run_command('g.copy', raster='%s,%sfilled' % (input, prefix), overwrite=True)
                     p.returncode = 0

scripts/r.fillnulls/testsuite/test_r_fillnulls.py

@@ -3,6 +3,7 @@ Created on Sun Jun 07 21:57:07 2018
 
 @author: Sanjeet Bhatti
 """
+import os
 
 from grass.gunittest.case import TestCase
 from grass.gunittest.main import test
@@ -13,36 +14,42 @@ from grass.script.core import run_command
 class TestRFillNulls(TestCase):
     """Test r.fillnulls script"""
 
-    mapName = 'elev_srtm_30m'
-    expression = 'elev_srtm_30m_filt = if(elev_srtm_30m < 50.0, \
-    null(), elev_srtm_30m)'
-    mapNameCalc = 'elev_srtm_30m_filt'
-    mapComplete = 'elev_srtm_30m_complete'
+    module_dir = os.path.dirname(os.path.dirname(__file__))
+    module = os.path.join(module_dir, 'r.fillnulls.py')
+    mapName = 'elevation'
+    expression = 'elevation_filt = if(elevation > 130, \
+    null(), elevation)'
+    mapNameCalc = 'elevation_filt'
+    mapComplete = 'elevation_complete'
     values = 'null_cells=0'
 
-    @classmethod
-    def setUpClass(cls):
+    def setUp(self):
         """Create maps in a small region."""
-        cls.use_temp_region()
-        cls.runModule('g.region', raster=cls.mapName, flags='p')
-
-    @classmethod
-    def tearDownClass(cls):
-        """Remove temporary region"""
-        cls.runModule('g.remove', flags='f', type='raster',
-                      name=(cls.mapNameCalc, cls.mapComplete))
-        cls.del_temp_region()
-
-    def test_fill_nulls(self):
-        """Fill nulls test"""
+        self.use_temp_region()
+        self.runModule('g.region', res=200, raster=self.mapName, flags='ap')
         run_command('r.mapcalc', expression=self.expression)
 
-        module = SimpleModule('r.fillnulls', input=self.mapNameCalc,
-                              output=self.mapComplete, tension=20)
+    def tearDown(self):
+        """Remove temporary region"""
+        self.runModule('g.remove', flags='f', type='raster',
+                       name=(self.mapNameCalc, self.mapComplete))
+        self.del_temp_region()
+
+    def test_rst(self):
+        module = SimpleModule(self.module, input=self.mapNameCalc,
+                              output=self.mapComplete, segmax=1200,
+                              npmin=100, tension=150)
         self.assertModule(module)
+        self.assertRasterFitsUnivar(raster=self.mapComplete,
+                                    reference=self.values)
 
+    def test_bspline(self):
+        module = SimpleModule(self.module, input=self.mapNameCalc,
+                              output=self.mapComplete, method='bicubic')
+        self.assertModule(module)
         self.assertRasterFitsUnivar(raster=self.mapComplete,
                                     reference=self.values)
 
+
 if __name__ == '__main__':
     test()