Add unconfigured_noop enhancement for RGBs

satpy/enhancements/__init__.py

@@ -30,6 +30,15 @@ def noop(img, **kwargs):
     return img
 
 
+def unconfigured_noop(img, **kwargs):
+    """Do nothing and warn that no enhancement was configured."""
+    import warnings
+    name = img.data.attrs.get('name', '<unknown>')
+    warnings.warn("No enhancement configured for '{}'. Will not stretch and "
+                  "assuming already 0-1 normalized.".format(name))
+    return noop(img, **kwargs)
+
+
 def stretch(img, **kwargs):
     """Perform stretch."""
     return img.stretch(**kwargs)

satpy/etc/enhancements/generic.yaml

@@ -10,7 +10,7 @@ enhancements:
     mode: RGB
     operations:
       - name: passive
-        method: !!python/name:satpy.enhancements.noop
+        method: !!python/name:satpy.enhancements.unconfigured_noop
   reflectance_default:
     standard_name: toa_bidirectional_reflectance
     operations:

satpy/tests/compositor_tests/__init__.py

@@ -382,7 +382,7 @@ def test_basic_sza(self):
         comp = DayNightCompositor(name='dn_test')
         res = comp((self.data_a, self.data_b, self.sza))
         res = res.compute()
-        expected = np.array([[0., 0.2985455], [0.51680423, 1.]])
+        expected = np.array([[0.1, 0.20499086], [0.48003658, 0.75]])
         np.testing.assert_allclose(res.values[0], expected)
 
     def test_basic_area(self):
@@ -391,7 +391,7 @@ def test_basic_area(self):
         comp = DayNightCompositor(name='dn_test')
         res = comp((self.data_a, self.data_b))
         res = res.compute()
-        expected = np.array([[0., 0.33164983], [0.66835017, 1.]])
+        expected = np.array([[0.1, 0.2], [0.3, 0.4]])
         np.testing.assert_allclose(res.values[0], expected)