Add test for unhandled NaN values

nabu/preproc/tests/test_flatfield.py

@@ -277,25 +277,29 @@ class TestFlatField:
         """
         radios, flats, darks, config = self.get_test_elements("two_flats_with_radios_indices")
 
+        # Retrieve the actual data for radios/darks/flats to use FlatField instead of FlatFieldDataUrl.
+        # Create a setting yielding "0/0": one pixel such that flat==dark and radio==dark
         for flat_idx, flat_url in flats.items():
             flats[flat_idx] = get_data(flat_url)
+            flats[flat_idx][0, 0] = 99
         for dark_idx, dark_url in darks.items():
             darks[dark_idx] = get_data(dark_url)
+            darks[dark_idx][0, 0] = 99
+        radios[:, 0, 0] = 99
 
-        radios[0] == darks[0]
-        flats[list(flats.keys())[0]] = darks[0]
-        FF = FlatField(radios.shape, flats, darks, radios_indices=config["radios_indices"])
-        FF.normalize_radios(radios)
-        # TODO adapt expected results to account for modified radios[0] and flats[0]. The interpolation is different!
+        # FlatField() without NaN handling yields NaN and raises RuntimeWarning
+        FF_no_nan_handling = FlatField(
+            radios.shape, flats, darks,
+            radios_indices=config["radios_indices"], nan_value=None
+        )
+        with pytest.warns(RuntimeWarning):
+            FF_no_nan_handling.normalize_radios(radios)
+        assert np.alltrue(np.logical_not(np.isfinite(radios[:, 0, 0]))), "First pixel should be nan or inf"
+        radios[:, 0, 0] = radios[:, 1, 1]
         self.check_normalized_radios(radios, config["expected_result"])
 
 
 
-
-
-
-
-
 # This test should be closer to the ESRF standard setting.
 # There are 2 flats, one dark, 4000 radios.
 #  dark :  indice=0     value=10