r.watershed: add test (author: Stephanie Wendel, swendel621, https://trac.osgeo.org/grass/ticket/2663)

 * original repository: https://github.com/swwendel/GRASS-r.Watershed-UnitTest
 * additional PEP8 changes, introducing few more variables, changed cls to self for normal methods, shorten or reformated comments, TODOs, optimize imports, simplify list syntax for g.remove


git-svn-id: https://svn.osgeo.org/grass/grass/trunk@65145 15284696-431f-4ddb-bdfa-cd5b030d7da7

raster/r.watershed/testsuite/r_watershed_test.py

@@ -0,0 +1,153 @@
+"""
+Name:      r_watershed_test
+Purpose:   This script is to demonstrate a unit test for r.watershed
+           module (originally developed for GIS582 course at NCSU).
+
+Author:    Stephanie Wendel
+Copyright: (C) 205 by Stephanie Wendel and the GRASS Development Team
+Licence:   This program is free software under the GNU General Public
+           License (>=v2). Read the file COPYING that comes with GRASS
+           for details.
+"""
+
+import grass.gunittest
+
+
+class TestWatershed(grass.gunittest.TestCase):
+    """Test case for watershed module"""
+
+    # Setup variables to be used for outputs
+    accumulation = 'test_accumulation'
+    drainage = 'test_drainage'
+    basin = 'test_basin'
+    stream = 'test_stream'
+    halfbasin = 'test_halfbasin'
+    slopelength = 'test_slopelength'
+    slopesteepness = 'test_slopesteepness'
+    elevation = 'elevation'
+    lengthslope_2 = 'test_lengthslope_2'
+    stream_2 = 'test_stream_2'
+
+    @classmethod
+    def setUpClass(cls):
+        """Ensures expected computational region and setup"""
+        # Always use the computational region of the raster elevation
+        cls.use_temp_region()
+        cls.runModule('g.region', raster=cls.elevation)
+
+    @classmethod
+    def tearDownClass(cls):
+        """Remove the temporary region"""
+        cls.del_temp_region()
+
+    def tearDown(self):
+        """Remove the outputs created from the watershed module
+
+        This is executed after each test run.
+        """
+        self.runModule('g.remove', flags='f', type='raster',
+                       name=[self.accumulation, self.drainage,
+                             self.basin, self.stream,
+                             self.halfbasin, self.slopelength,
+                             self.slopesteepness, self.lengthslope_2,
+                             self.stream_2])
+
+    def test_OutputCreated(self):
+        """Test to see if the outputs are created"""
+        # run the watershed module
+        self.assertModule('r.watershed', elevation=self.elevation,
+                          threshold='10000', accumulation=self.accumulation,
+                          drainage=self.drainage, basin=self.basin, stream=self.stream,
+                          half_basin=self.halfbasin, length_slope=self.slopelength,
+                          slope_steepness=self.slopesteepness)
+        # check to see if accumulation output is in mapset
+        self.assertRasterExists(self.accumulation,
+                                msg='accumulation output was not created')
+        # check to see if drainage output is in mapset
+        self.assertRasterExists(self.drainage,
+                                msg='drainage output was not created')
+        # check to see if basin output is in mapset
+        self.assertRasterExists(self.basin,
+                                msg='basin output was not created')
+        # check to see if stream output is in mapset
+        self.assertRasterExists(self.stream,
+                                msg='stream output was not created')
+        # check to see if half.basin output is in mapset
+        self.assertRasterExists(self.halfbasin,
+                                msg='half.basin output was not created')
+        # check to see if length.slope output is in mapset
+        self.assertRasterExists(self.slopelength,
+                                msg='length.slope output was not created')
+        # check to see if slope.steepness output is in mapset
+        self.assertRasterExists(self.slopesteepness,
+                                msg='slope.steepness output was not created')
+
+    def test_fourFlag(self):
+        """Test the -4 flag and the stream and slope lengths
+
+        Tests the -4 flag to see if the stream and slope lengths are
+        approximately the same as the outputs from the default
+        module run.
+        """
+        # Run module with default settings
+        self.assertModule('r.watershed', elevation=self.elevation,
+                          threshold='10000', stream=self.stream,
+                          length_slope=self.slopelength, overwrite=True)
+        # Run module with flag 4
+        self.assertModule('r.watershed', flags='4', elevation='elevation',
+                          threshold='10000', stream=self.stream_2,
+                          length_slope=self.lengthslope_2)
+        # Use the assertRastersNoDifference with precsion 100 to see if close
+        # Compare stream output
+        self.assertRastersNoDifference(self.stream_2, self.stream, 100)
+        # Compare length_slope output
+        self.assertRastersNoDifference(self.lengthslope_2,
+                                       self.slopelength, 10)
+
+    def test_watershedThreadholdfail(self):
+        """Test if threshold of 0 or a negative is accepted
+
+        The module should fail in this test, if it fails, test succeeds.
+        """
+        self.assertModuleFail('r.watershed', elevation=self.elevation,
+                              threshold='0', stream=self.stream, overwrite=True,
+                              msg='Threshold value of 0 considered valid.')
+        self.assertModuleFail('r.watershed', elevation=self.elevation,
+                              threshold='-1', stream=self.stream, overwrite=True,
+                              msg='Threshold value of 0 considered valid.')
+
+    def test_thresholdsize(self):
+        """Test the expected range of basin output values"""
+        self.assertModule('r.watershed', elevation=self.elevation,
+                          threshold='100000', basin=self.basin, overwrite=True)
+        # it is expected that 100k Threshold has a min=2 and max=12 for this
+        # data
+        self.assertRasterMinMax(self.basin, 2, 12)
+        # it is expected that 100k Threshold has a min=2 and max=256 for this
+        # data
+        self.assertModule('r.watershed', elevation=self.elevation,
+                          threshold='10000', basin=self.basin, overwrite=True)
+        self.assertRasterMinMax(self.basin, 2, 256)
+
+    def test_drainageDirection(self):
+        """Test if the drainage direction is between -8 and 8."""
+        self.assertModule('r.watershed', elevation=self.elevation,
+                          threshold='100000', drainage=self.drainage)
+        # Make sure the min/max is between -8 and 8
+        self.assertRasterMinMax(self.drainage, -8, 8,
+                                msg='Direction must be between -8 and 8')
+
+    def test_basinValue(self):
+        """Check to see if the basin value is 0 or greater"""
+        self.assertModule('r.watershed', elevation=self.elevation,
+                          threshold='10000', basin=self.basin)
+        # Make sure the minimum value is 0 for basin value representing unique
+        # positive integer.
+        # TODO: test just min, max is theoretically unlimited
+        # or set a lower value according to what is expected with this data
+        # TODO: add test which tests that 'max basin id' == 'num of basins'
+        self.assertRasterMinMax(self.basin, 0, 1000000,
+                                msg='A basin value is less than 0 or greater than 1000000')
+
+if __name__ == '__main__':
+    grass.gunittest.test()