r.rgb: added test, thanks to Sanjeet Bhatti

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@74251 15284696-431f-4ddb-bdfa-cd5b030d7da7

scripts/r.rgb/testsuite/test_r_rgb.py

@@ -0,0 +1,44 @@
+"""
+Created on Sun Jun 08 13:20:31 2018
+
+@author: Sanjeet Bhatti
+"""
+
+from grass.gunittest.case import TestCase
+from grass.gunittest.main import test
+from grass.gunittest.gmodules import SimpleModule
+
+
+class TestRRGB(TestCase):
+    """Test r.rgb script"""
+
+    mapName = 'elevation'
+    red = 'elevation.r'
+    green = 'elevation.g'
+    blue = 'elevation.b'
+
+    @classmethod
+    def setUpClass(cls):
+        """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.red, cls.green, cls.blue))
+        cls.del_temp_region()
+
+    def test_rgb_maps(self):
+        """Generates rgb maps from a raster map test"""
+        module = SimpleModule('r.rgb', input=self.mapName, red=self.red,
+                              green=self.green, blue=self.blue)
+        self.assertModule(module)
+
+        self.assertRasterExists(self.red)
+        self.assertRasterExists(self.green)
+        self.assertRasterExists(self.blue)
+
+if __name__ == '__main__':
+    test()