test_composites.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright (c) 2018-2020 Satpy developers
#
# This file is part of satpy.
#
# satpy is free software: you can redistribute it and/or modify it under the
# terms of the GNU General Public License as published by the Free Software
# Foundation, either version 3 of the License, or (at your option) any later
# version.
#
# satpy is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along with
# satpy.  If not, see <http://www.gnu.org/licenses/>.
"""Tests for compositors in composites/__init__.py."""

import os
import unittest
from datetime import datetime
from unittest import mock

import dask
import dask.array as da
import numpy as np
import pytest
import xarray as xr
from pyresample import AreaDefinition

import satpy


class TestMatchDataArrays(unittest.TestCase):
    """Test the utility method 'match_data_arrays'."""

    def _get_test_ds(self, shape=(50, 100), dims=('y', 'x')):
        """Get a fake DataArray."""
        from pyresample.geometry import AreaDefinition
        data = da.random.random(shape, chunks=25)
        area = AreaDefinition(
            'test', 'test', 'test',
            {'proj': 'eqc', 'lon_0': 0.0,
             'lat_0': 0.0},
            shape[dims.index('x')], shape[dims.index('y')],
            (-20037508.34, -10018754.17, 20037508.34, 10018754.17))
        attrs = {'area': area}
        return xr.DataArray(data, dims=dims, attrs=attrs)

    def test_single_ds(self):
        """Test a single dataset is returned unharmed."""
        from satpy.composites import CompositeBase
        ds1 = self._get_test_ds()
        comp = CompositeBase('test_comp')
        ret_datasets = comp.match_data_arrays((ds1,))
        assert ret_datasets[0].identical(ds1)

    def test_mult_ds_area(self):
        """Test multiple datasets successfully pass."""
        from satpy.composites import CompositeBase
        ds1 = self._get_test_ds()
        ds2 = self._get_test_ds()
        comp = CompositeBase('test_comp')
        ret_datasets = comp.match_data_arrays((ds1, ds2))
        assert ret_datasets[0].identical(ds1)
        assert ret_datasets[1].identical(ds2)

    def test_mult_ds_no_area(self):
        """Test that all datasets must have an area attribute."""
        from satpy.composites import CompositeBase
        ds1 = self._get_test_ds()
        ds2 = self._get_test_ds()
        del ds2.attrs['area']
        comp = CompositeBase('test_comp')
        self.assertRaises(ValueError, comp.match_data_arrays, (ds1, ds2))

    def test_mult_ds_diff_area(self):
        """Test that datasets with different areas fail."""
        from pyresample.geometry import AreaDefinition

        from satpy.composites import CompositeBase, IncompatibleAreas
        ds1 = self._get_test_ds()
        ds2 = self._get_test_ds()
        ds2.attrs['area'] = AreaDefinition(
            'test', 'test', 'test',
            {'proj': 'eqc', 'lon_0': 0.0,
             'lat_0': 0.0},
            100, 50,
            (-30037508.34, -20018754.17, 10037508.34, 18754.17))
        comp = CompositeBase('test_comp')
        self.assertRaises(IncompatibleAreas, comp.match_data_arrays, (ds1, ds2))

    def test_mult_ds_diff_dims(self):
        """Test that datasets with different dimensions still pass."""
        from satpy.composites import CompositeBase

        # x is still 50, y is still 100, even though they are in
        # different order
        ds1 = self._get_test_ds(shape=(50, 100), dims=('y', 'x'))
        ds2 = self._get_test_ds(shape=(3, 100, 50), dims=('bands', 'x', 'y'))
        comp = CompositeBase('test_comp')
        ret_datasets = comp.match_data_arrays((ds1, ds2))
        assert ret_datasets[0].identical(ds1)
        assert ret_datasets[1].identical(ds2)

    def test_mult_ds_diff_size(self):
        """Test that datasets with different sizes fail."""
        from satpy.composites import CompositeBase, IncompatibleAreas

        # x is 50 in this one, 100 in ds2
        # y is 100 in this one, 50 in ds2
        ds1 = self._get_test_ds(shape=(50, 100), dims=('x', 'y'))
        ds2 = self._get_test_ds(shape=(3, 50, 100), dims=('bands', 'y', 'x'))
        comp = CompositeBase('test_comp')
        self.assertRaises(IncompatibleAreas, comp.match_data_arrays, (ds1, ds2))

    def test_nondimensional_coords(self):
        """Test the removal of non-dimensional coordinates when compositing."""
        from satpy.composites import CompositeBase
        ds = self._get_test_ds(shape=(2, 2))
        ds['acq_time'] = ('y', [0, 1])
        comp = CompositeBase('test_comp')
        ret_datasets = comp.match_data_arrays([ds, ds])
        self.assertNotIn('acq_time', ret_datasets[0].coords)


class TestRatioSharpenedCompositors(unittest.TestCase):
    """Test RatioSharpenedRGB and SelfSharpendRGB compositors."""

    def setUp(self):
        """Create test data."""
        from pyresample.geometry import AreaDefinition
        area = AreaDefinition('test', 'test', 'test',
                              {'proj': 'merc'}, 2, 2,
                              (-2000, -2000, 2000, 2000))
        attrs = {'area': area,
                 'start_time': datetime(2018, 1, 1, 18),
                 'modifiers': tuple(),
                 'resolution': 1000,
                 'calibration': 'reflectance',
                 'units': '%',
                 'name': 'test_vis'}
        low_res_data = np.ones((2, 2), dtype=np.float64) + 4
        low_res_data[1, 1] = 0.0  # produces infinite ratio
        ds1 = xr.DataArray(da.from_array(low_res_data, chunks=2),
                           attrs=attrs, dims=('y', 'x'),
                           coords={'y': [0, 1], 'x': [0, 1]})
        self.ds1 = ds1
        ds2 = xr.DataArray(da.ones((2, 2), chunks=2, dtype=np.float64) + 2,
                           attrs=attrs, dims=('y', 'x'),
                           coords={'y': [0, 1], 'x': [0, 1]})
        ds2.attrs['name'] += '2'
        self.ds2 = ds2
        ds3 = xr.DataArray(da.ones((2, 2), chunks=2, dtype=np.float64) + 3,
                           attrs=attrs, dims=('y', 'x'),
                           coords={'y': [0, 1], 'x': [0, 1]})
        ds3.attrs['name'] += '3'
        self.ds3 = ds3

        # high resolution version
        high_res_data = np.ones((2, 2), dtype=np.float64)
        high_res_data[1, 0] = np.nan  # invalid value in one band
        ds4 = xr.DataArray(da.from_array(high_res_data, chunks=2),
                           attrs=attrs, dims=('y', 'x'),
                           coords={'y': [0, 1], 'x': [0, 1]})
        ds4.attrs['name'] += '4'
        ds4.attrs['resolution'] = 500
        self.ds4 = ds4

        # high resolution version - but too big
        ds4 = xr.DataArray(da.ones((4, 4), chunks=2, dtype=np.float64),
                           attrs=attrs.copy(), dims=('y', 'x'),
                           coords={'y': [0, 1, 2, 3], 'x': [0, 1, 2, 3]})
        ds4.attrs['name'] += '4'
        ds4.attrs['resolution'] = 500
        ds4.attrs['rows_per_scan'] = 1
        ds4.attrs['area'] = AreaDefinition('test', 'test', 'test',
                                           {'proj': 'merc'}, 4, 4,
                                           (-2000, -2000, 2000, 2000))
        self.ds4_big = ds4

    def test_bad_color(self):
        """Test that only valid band colors can be provided."""
        from satpy.composites import RatioSharpenedRGB
        self.assertRaises(ValueError, RatioSharpenedRGB, name='true_color', high_resolution_band='bad')

    def test_match_data_arrays(self):
        """Test that all areas have to be the same resolution."""
        from satpy.composites import IncompatibleAreas, RatioSharpenedRGB
        comp = RatioSharpenedRGB(name='true_color')
        self.assertRaises(IncompatibleAreas, comp, (self.ds1, self.ds2, self.ds3), optional_datasets=(self.ds4_big,))

    def test_more_than_three_datasets(self):
        """Test that only 3 datasets can be passed."""
        from satpy.composites import RatioSharpenedRGB
        comp = RatioSharpenedRGB(name='true_color')
        self.assertRaises(ValueError, comp, (self.ds1, self.ds2, self.ds3, self.ds1),
                          optional_datasets=(self.ds4_big,))

    def test_basic_no_high_res(self):
        """Test that three datasets can be passed without optional high res."""
        from satpy.composites import RatioSharpenedRGB
        comp = RatioSharpenedRGB(name='true_color')
        res = comp((self.ds1, self.ds2, self.ds3))
        self.assertEqual(res.shape, (3, 2, 2))

    def test_basic_no_sharpen(self):
        """Test that color None does no sharpening."""
        from satpy.composites import RatioSharpenedRGB
        comp = RatioSharpenedRGB(name='true_color', high_resolution_band=None)
        res = comp((self.ds1, self.ds2, self.ds3), optional_datasets=(self.ds4,))
        self.assertEqual(res.shape, (3, 2, 2))

    def test_basic_red(self):
        """Test that basic high resolution red can be passed."""
        from satpy.composites import RatioSharpenedRGB
        comp = RatioSharpenedRGB(name='true_color')
        res = comp((self.ds1, self.ds2, self.ds3), optional_datasets=(self.ds4,))
        res = res.values
        self.assertEqual(res.shape, (3, 2, 2))
        np.testing.assert_allclose(res[0], self.ds4.values)
        np.testing.assert_allclose(res[1], np.array([[0.6, 0.6], [np.nan, 3.0]], dtype=np.float64))
        np.testing.assert_allclose(res[2], np.array([[0.8, 0.8], [np.nan, 4.0]], dtype=np.float64))

    def test_self_sharpened_no_high_res(self):
        """Test for exception when no high res band is specified."""
        from satpy.composites import SelfSharpenedRGB
        comp = SelfSharpenedRGB(name='true_color', high_resolution_band=None)
        self.assertRaises(ValueError, comp, (self.ds1, self.ds2, self.ds3))

    def test_self_sharpened_basic(self):
        """Test that three datasets can be passed without optional high res."""
        from satpy.composites import SelfSharpenedRGB
        comp = SelfSharpenedRGB(name='true_color')
        res = comp((self.ds1, self.ds2, self.ds3))
        res = res.values
        self.assertEqual(res.shape, (3, 2, 2))
        np.testing.assert_allclose(res[0], self.ds1.values)
        np.testing.assert_allclose(res[1], np.array([[4, 4], [4, 0]], dtype=np.float64))
        np.testing.assert_allclose(res[2], np.array([[5.333333, 5.333333], [5.333333, 0]], dtype=np.float64))

    def test_no_units(self):
        """Test that the computed RGB has no units attribute."""
        from satpy.composites import RatioSharpenedRGB
        comp = RatioSharpenedRGB(name='true_color')
        res = comp((self.ds1, self.ds2, self.ds3))
        assert "units" not in res.attrs


class TestDifferenceCompositor(unittest.TestCase):
    """Test case for the difference compositor."""

    def setUp(self):
        """Create test data."""
        from pyresample.geometry import AreaDefinition
        area = AreaDefinition('test', 'test', 'test',
                              {'proj': 'merc'}, 2, 2,
                              (-2000, -2000, 2000, 2000))
        attrs = {'area': area,
                 'start_time': datetime(2018, 1, 1, 18),
                 'modifiers': tuple(),
                 'resolution': 1000,
                 'name': 'test_vis'}
        ds1 = xr.DataArray(da.ones((2, 2), chunks=2, dtype=np.float64),
                           attrs=attrs, dims=('y', 'x'),
                           coords={'y': [0, 1], 'x': [0, 1]})
        self.ds1 = ds1
        ds2 = xr.DataArray(da.ones((2, 2), chunks=2, dtype=np.float64) + 2,
                           attrs=attrs, dims=('y', 'x'),
                           coords={'y': [0, 1], 'x': [0, 1]})
        ds2.attrs['name'] += '2'
        self.ds2 = ds2

        # high res version
        ds2 = xr.DataArray(da.ones((4, 4), chunks=2, dtype=np.float64) + 4,
                           attrs=attrs.copy(), dims=('y', 'x'),
                           coords={'y': [0, 1, 2, 3], 'x': [0, 1, 2, 3]})
        ds2.attrs['name'] += '2'
        ds2.attrs['resolution'] = 500
        ds2.attrs['rows_per_scan'] = 1
        ds2.attrs['area'] = AreaDefinition('test', 'test', 'test',
                                           {'proj': 'merc'}, 4, 4,
                                           (-2000, -2000, 2000, 2000))
        self.ds2_big = ds2

    def test_basic_diff(self):
        """Test that a basic difference composite works."""
        from satpy.composites import DifferenceCompositor
        comp = DifferenceCompositor(name='diff', standard_name='temperature_difference')
        res = comp((self.ds1, self.ds2))
        np.testing.assert_allclose(res.values, -2)
        assert res.attrs.get('standard_name') == 'temperature_difference'

    def test_bad_areas_diff(self):
        """Test that a difference where resolutions are different fails."""
        from satpy.composites import DifferenceCompositor, IncompatibleAreas
        comp = DifferenceCompositor(name='diff')
        # too many arguments
        self.assertRaises(ValueError, comp, (self.ds1, self.ds2, self.ds2_big))
        # different resolution
        self.assertRaises(IncompatibleAreas, comp, (self.ds1, self.ds2_big))


@pytest.fixture
def fake_area():
    """Return a fake 2×2 area."""
    from pyresample.geometry import create_area_def
    return create_area_def("skierffe", 4087, area_extent=[-5_000, -5_000, 5_000, 5_000], shape=(2, 2))


@pytest.fixture
def fake_dataset_pair(fake_area):
    """Return a fake pair of 2×2 datasets."""
    ds1 = xr.DataArray(
            da.full((2, 2), 8, chunks=2, dtype=np.float32), attrs={"area": fake_area})
    ds2 = xr.DataArray(
            da.full((2, 2), 4, chunks=2, dtype=np.float32), attrs={"area": fake_area})
    return (ds1, ds2)


def test_ratio_compositor(fake_dataset_pair):
    """Test the ratio compositor."""
    from satpy.composites import RatioCompositor
    comp = RatioCompositor(name="ratio", standard_name="channel_ratio")
    res = comp(fake_dataset_pair)
    np.testing.assert_allclose(res.values, 2)


def test_sum_compositor(fake_dataset_pair):
    """Test the sum compositor."""
    from satpy.composites import SumCompositor
    comp = SumCompositor(name="sum", standard_name="channel_sum")
    res = comp(fake_dataset_pair)
    np.testing.assert_allclose(res.values, 12)


class TestDayNightCompositor(unittest.TestCase):
    """Test DayNightCompositor."""

    def setUp(self):
        """Create test data."""
        bands = ['R', 'G', 'B']
        start_time = datetime(2018, 1, 1, 18, 0, 0)

        # RGB
        a = np.zeros((3, 2, 2), dtype=np.float64)
        a[:, 0, 0] = 0.1
        a[:, 0, 1] = 0.2
        a[:, 1, 0] = 0.3
        a[:, 1, 1] = 0.4
        a = da.from_array(a, a.shape)
        self.data_a = xr.DataArray(a, attrs={'test': 'a', 'start_time': start_time},
                                   coords={'bands': bands}, dims=('bands', 'y', 'x'))
        b = np.zeros((3, 2, 2), dtype=np.float64)
        b[:, 0, 0] = np.nan
        b[:, 0, 1] = 0.25
        b[:, 1, 0] = 0.50
        b[:, 1, 1] = 0.75
        b = da.from_array(b, b.shape)
        self.data_b = xr.DataArray(b, attrs={'test': 'b', 'start_time': start_time},
                                   coords={'bands': bands}, dims=('bands', 'y', 'x'))

        sza = np.array([[80., 86.], [94., 100.]])
        sza = da.from_array(sza, sza.shape)
        self.sza = xr.DataArray(sza, dims=('y', 'x'))

        # fake area
        my_area = AreaDefinition(
            "test", "", "",
            "+proj=longlat",
            2, 2,
            (-95.0, 40.0, -92.0, 43.0),
        )
        self.data_a.attrs['area'] = my_area
        self.data_b.attrs['area'] = my_area
        # not used except to check that it matches the data arrays
        self.sza.attrs['area'] = my_area

    def test_daynight_sza(self):
        """Test compositor with both day and night portions when SZA data is included."""
        from satpy.composites import DayNightCompositor
        comp = DayNightCompositor(name='dn_test', day_night="day_night")
        res = comp((self.data_a, self.data_b, self.sza))
        res = res.compute()
        expected = np.array([[0., 0.22122352], [0.5, 1.]])
        np.testing.assert_allclose(res.values[0], expected)

    def test_daynight_area(self):
        """Test compositor both day and night portions when SZA data is not provided."""
        from satpy.composites import DayNightCompositor
        comp = DayNightCompositor(name='dn_test', day_night="day_night")
        res = comp((self.data_a, self.data_b))
        res = res.compute()
        expected = np.array([[0., 0.33164983], [0.66835017, 1.]])
        np.testing.assert_allclose(res.values[0], expected)

    def test_night_only_sza(self):
        """Test compositor with night portion when SZA data is included."""
        from satpy.composites import DayNightCompositor
        comp = DayNightCompositor(name='dn_test', day_night="night_only")
        res = comp((self.data_b, self.sza))
        res = res.compute()
        expected = np.array([[np.nan, 0.], [0.5, 1.]])
        np.testing.assert_allclose(res.values[0], expected)

    def test_night_only_area(self):
        """Test compositor with night portion when SZA data is not provided."""
        from satpy.composites import DayNightCompositor
        comp = DayNightCompositor(name='dn_test', day_night="night_only")
        res = comp((self.data_b))
        res = res.compute()
        expected = np.array([[np.nan, 0.], [0., 0.]])
        np.testing.assert_allclose(res.values[0], expected)

    def test_day_only_sza(self):
        """Test compositor with day portion when SZA data is included."""
        from satpy.composites import DayNightCompositor
        comp = DayNightCompositor(name='dn_test', day_night="day_only")
        res = comp((self.data_a, self.sza))
        res = res.compute()
        expected = np.array([[0., 0.22122352], [0., 0.]])
        np.testing.assert_allclose(res.values[0], expected)

    def test_day_only_area(self):
        """Test compositor with day portion when SZA data is not provided."""
        from satpy.composites import DayNightCompositor
        comp = DayNightCompositor(name='dn_test', day_night="day_only")
        res = comp((self.data_a))
        res = res.compute()
        expected = np.array([[0., 0.33164983], [0.66835017, 1.]])
        np.testing.assert_allclose(res.values[0], expected)


class TestFillingCompositor(unittest.TestCase):
    """Test case for the filling compositor."""

    def test_fill(self):
        """Test filling."""
        from satpy.composites import FillingCompositor
        comp = FillingCompositor(name='fill_test')
        filler = xr.DataArray(np.array([1, 2, 3, 4, 3, 2, 1]))
        red = xr.DataArray(np.array([1, 2, 3, np.nan, 3, 2, 1]))
        green = xr.DataArray(np.array([np.nan, 2, 3, 4, 3, 2, np.nan]))
        blue = xr.DataArray(np.array([4, 3, 2, 1, 2, 3, 4]))
        res = comp([filler, red, green, blue])
        np.testing.assert_allclose(res.sel(bands='R').data, filler.data)
        np.testing.assert_allclose(res.sel(bands='G').data, filler.data)
        np.testing.assert_allclose(res.sel(bands='B').data, blue.data)


class TestMultiFiller(unittest.TestCase):
    """Test case for the MultiFiller compositor."""

    def test_fill(self):
        """Test filling."""
        from satpy.composites import MultiFiller
        comp = MultiFiller(name='fill_test')
        attrs = {"units": "K"}
        a = xr.DataArray(
                np.array([1, np.nan, np.nan, np.nan, np.nan, np.nan, np.nan]),
                attrs=attrs.copy())
        b = xr.DataArray(
                np.array([np.nan, 2, 3, np.nan, np.nan, np.nan, np.nan]),
                attrs=attrs.copy())
        c = xr.DataArray(
                np.array([np.nan, 22, 3, np.nan, np.nan, np.nan, 7]),
                attrs=attrs.copy())
        d = xr.DataArray(
                np.array([np.nan, np.nan, np.nan, np.nan, np.nan, 6, np.nan]),
                attrs=attrs.copy())
        e = xr.DataArray(
                np.array([np.nan, np.nan, np.nan, np.nan, 5, np.nan, np.nan]),
                attrs=attrs.copy())
        expected = xr.DataArray(np.array([1, 2, 3, np.nan, 5, 6, 7]))
        res = comp([a, b, c], optional_datasets=[d, e])
        np.testing.assert_allclose(res.data, expected.data)
        assert "units" in res.attrs
        assert res.attrs["units"] == "K"


class TestLuminanceSharpeningCompositor(unittest.TestCase):
    """Test luminance sharpening compositor."""

    def test_compositor(self):
        """Test luminance sharpening compositor."""
        from satpy.composites import LuminanceSharpeningCompositor
        comp = LuminanceSharpeningCompositor(name='test')
        # Three shades of grey
        rgb_arr = np.array([1, 50, 100, 200, 1, 50, 100, 200, 1, 50, 100, 200])
        rgb = xr.DataArray(rgb_arr.reshape((3, 2, 2)),
                           dims=['bands', 'y', 'x'], coords={'bands': ['R', 'G', 'B']})
        # 100 % luminance -> all result values ~1.0
        lum = xr.DataArray(np.array([[100., 100.], [100., 100.]]),
                           dims=['y', 'x'])
        res = comp([lum, rgb])
        np.testing.assert_allclose(res.data, 1., atol=1e-9)
        # 50 % luminance, all result values ~0.5
        lum = xr.DataArray(np.array([[50., 50.], [50., 50.]]),
                           dims=['y', 'x'])
        res = comp([lum, rgb])
        np.testing.assert_allclose(res.data, 0.5, atol=1e-9)
        # 30 % luminance, all result values ~0.3
        lum = xr.DataArray(np.array([[30., 30.], [30., 30.]]),
                           dims=['y', 'x'])
        res = comp([lum, rgb])
        np.testing.assert_allclose(res.data, 0.3, atol=1e-9)
        # 0 % luminance, all values ~0.0
        lum = xr.DataArray(np.array([[0., 0.], [0., 0.]]),
                           dims=['y', 'x'])
        res = comp([lum, rgb])
        np.testing.assert_allclose(res.data, 0.0, atol=1e-9)


class TestSandwichCompositor:
    """Test sandwich compositor."""

    # Test RGB and RGBA
    @pytest.mark.parametrize(
        "input_shape,bands",
        [
            ((3, 2, 2), ['R', 'G', 'B']),
            ((4, 2, 2), ['R', 'G', 'B', 'A'])
        ]
    )
    @mock.patch('satpy.composites.enhance2dataset')
    def test_compositor(self, e2d, input_shape, bands):
        """Test luminance sharpening compositor."""
        from satpy.composites import SandwichCompositor

        rgb_arr = da.from_array(np.random.random(input_shape), chunks=2)
        rgb = xr.DataArray(rgb_arr, dims=['bands', 'y', 'x'],
                           coords={'bands': bands})
        lum_arr = da.from_array(100 * np.random.random((2, 2)), chunks=2)
        lum = xr.DataArray(lum_arr, dims=['y', 'x'])

        # Make enhance2dataset return unmodified dataset
        e2d.return_value = rgb
        comp = SandwichCompositor(name='test')

        res = comp([lum, rgb])

        for band in rgb:
            if band.bands != 'A':
                # Check compositor has modified this band
                np.testing.assert_allclose(res.loc[band.bands].to_numpy(),
                                           band.to_numpy() * lum_arr / 100.)
            else:
                # Check Alpha band remains intact
                np.testing.assert_allclose(res.loc[band.bands].to_numpy(),
                                           band.to_numpy())
        # make sure the compositor doesn't modify the input data
        np.testing.assert_allclose(lum.values, lum_arr.compute())


class TestInlineComposites(unittest.TestCase):
    """Test inline composites."""

    def test_inline_composites(self):
        """Test that inline composites are working."""
        from satpy.composites.config_loader import load_compositor_configs_for_sensors
        comps = load_compositor_configs_for_sensors(['visir'])[0]
        # Check that "fog" product has all its prerequisites defined
        keys = comps['visir'].keys()
        fog = [comps['visir'][dsid] for dsid in keys if "fog" == dsid['name']][0]
        self.assertEqual(fog.attrs['prerequisites'][0]['name'], '_fog_dep_0')
        self.assertEqual(fog.attrs['prerequisites'][1]['name'], '_fog_dep_1')
        self.assertEqual(fog.attrs['prerequisites'][2], 10.8)

        # Check that the sub-composite dependencies use wavelengths
        # (numeric values)
        keys = comps['visir'].keys()
        fog_dep_ids = [dsid for dsid in keys if "fog_dep" in dsid['name']]
        self.assertEqual(comps['visir'][fog_dep_ids[0]].attrs['prerequisites'],
                         [12.0, 10.8])
        self.assertEqual(comps['visir'][fog_dep_ids[1]].attrs['prerequisites'],
                         [10.8, 8.7])

        # Check the same for SEVIRI and verify channel names are used
        # in the sub-composite dependencies instead of wavelengths
        comps = load_compositor_configs_for_sensors(['seviri'])[0]
        keys = comps['seviri'].keys()
        fog_dep_ids = [dsid for dsid in keys if "fog_dep" in dsid['name']]
        self.assertEqual(comps['seviri'][fog_dep_ids[0]].attrs['prerequisites'],
                         ['IR_120', 'IR_108'])
        self.assertEqual(comps['seviri'][fog_dep_ids[1]].attrs['prerequisites'],
                         ['IR_108', 'IR_087'])


class TestColormapCompositor(unittest.TestCase):
    """Test the ColormapCompositor."""

    def setUp(self):
        """Set up the test case."""
        from satpy.composites import ColormapCompositor
        self.colormap_compositor = ColormapCompositor('test_cmap_compositor')

    def test_build_colormap_with_int_data_and_without_meanings(self):
        """Test colormap building."""
        palette = np.array([[0, 0, 0], [127, 127, 127], [255, 255, 255]])
        colormap, squeezed_palette = self.colormap_compositor.build_colormap(palette, np.uint8, {})
        self.assertTrue(np.allclose(colormap.values, [0, 1]))
        self.assertTrue(np.allclose(squeezed_palette, palette / 255.0))

    def test_build_colormap_with_int_data_and_with_meanings(self):
        """Test colormap building."""
        palette = xr.DataArray(np.array([[0, 0, 0], [127, 127, 127], [255, 255, 255]]),
                               dims=['value', 'band'])
        palette.attrs['palette_meanings'] = [2, 3, 4]
        colormap, squeezed_palette = self.colormap_compositor.build_colormap(palette, np.uint8, {})
        self.assertTrue(np.allclose(colormap.values, [2, 3, 4]))
        self.assertTrue(np.allclose(squeezed_palette, palette / 255.0))


class TestPaletteCompositor(unittest.TestCase):
    """Test the PaletteCompositor."""

    def test_call(self):
        """Test palette compositing."""
        from satpy.composites import PaletteCompositor
        cmap_comp = PaletteCompositor('test_cmap_compositor')
        palette = xr.DataArray(np.array([[0, 0, 0], [127, 127, 127], [255, 255, 255]]),
                               dims=['value', 'band'])
        palette.attrs['palette_meanings'] = [2, 3, 4]

        data = xr.DataArray(da.from_array(np.array([[4, 3, 2], [2, 3, 4]], dtype=np.uint8)), dims=['y', 'x'])
        res = cmap_comp([data, palette])
        exp = np.array([[[1., 0.498039, 0.],
                         [0., 0.498039, 1.]],
                        [[1., 0.498039, 0.],
                         [0., 0.498039, 1.]],
                        [[1., 0.498039, 0.],
                         [0., 0.498039, 1.]]])
        self.assertTrue(np.allclose(res, exp))


class TestColorizeCompositor(unittest.TestCase):
    """Test the ColorizeCompositor."""

    def test_colorize_no_fill(self):
        """Test colorizing."""
        from satpy.composites import ColorizeCompositor
        colormap_composite = ColorizeCompositor('test_color_compositor')
        palette = xr.DataArray(np.array([[0, 0, 0], [127, 127, 127], [255, 255, 255]]),
                               dims=['value', 'band'])
        palette.attrs['palette_meanings'] = [2, 3, 4]

        data = xr.DataArray(np.array([[4, 3, 2],
                                      [2, 3, 4]],
                                     dtype=np.uint8),
                            dims=['y', 'x'])
        res = colormap_composite([data, palette])
        exp = np.array([[[1., 0.498039, 0.],
                         [0., 0.498039, 1.]],
                        [[1., 0.498039, 0.],
                         [0., 0.498039, 1.]],
                        [[1., 0.498039, 0.],
                         [0., 0.498039, 1.]]])
        self.assertTrue(np.allclose(res, exp, atol=1e-4))

    def test_colorize_with_interpolation(self):
        """Test colorizing with interpolation."""
        from satpy.composites import ColorizeCompositor
        colormap_composite = ColorizeCompositor('test_color_compositor')
        palette = xr.DataArray(np.array([[0, 0, 0], [127, 127, 127], [255, 255, 255]]),
                               dims=['value', 'band'])
        palette.attrs['palette_meanings'] = [2, 3, 4]

        data = xr.DataArray(da.from_array(np.array([[4, 3, 2.5],
                                                    [2, 3.2, 4]])),
                            dims=['y', 'x'],
                            attrs={'valid_range': np.array([2, 4])})
        res = colormap_composite([data, palette])
        exp = np.array([[[1.0000149, 0.49804664, 0.24907766],
                         [0., 0.59844028, 1.0000149]],
                        [[1.00005405, 0.49806613, 0.24902255],
                         [0., 0.59846373, 1.00005405]],
                        [[1.00001585, 0.49804711, 0.24896771],
                         [0., 0.59844073, 1.00001585]]])
        self.assertTrue(np.allclose(res, exp, atol=1e-4))


class TestCloudTopHeightCompositor(unittest.TestCase):
    """Test the CloudTopHeightCompositor."""

    def setUp(self):
        """Set up the test case."""
        from satpy.composites.cloud_products import CloudTopHeightCompositor
        self.colormap_composite = CloudTopHeightCompositor('test_cmap_compositor')
        self.palette = xr.DataArray(np.array([[0, 0, 0], [127, 127, 127], [255, 255, 255]]),
                                    dims=['value', 'band'])
        self.palette.attrs['palette_meanings'] = [2, 3, 4]

        self.exp = np.array([[[0., 0.498, 0.],
                              [0., 0.498, np.nan]],
                             [[0., 0.498, 0.],
                              [0., 0.498, np.nan]],
                             [[0., 0.498, 0.],
                              [0., 0.498, np.nan]]])
        self.exp_all_valid = np.array([[[0., 0.498, 0.],
                                        [0., 0.498, 0.]],
                                       [[0., 0.498, 0.],
                                        [0., 0.498, 0.]],
                                       [[0., 0.498, 0.],
                                        [0., 0.498, 0.]]])

    def test_call_numpy_with_invalid_value_in_status(self):
        """Test the CloudTopHeight composite generation."""
        status = xr.DataArray(np.array([[1, 0, 1], [1, 0, 65535]]), dims=['y', 'x'],
                              attrs={'_FillValue': 65535})
        data = xr.DataArray(np.array([[4, 3, 2], [2, 3, 4]], dtype=np.uint8),
                            dims=['y', 'x'])
        res = self.colormap_composite([data, self.palette, status])

        np.testing.assert_allclose(res, self.exp, atol=1e-4)

    def test_call_dask_with_invalid_value_in_status(self):
        """Test the CloudTopHeight composite generation."""
        status = xr.DataArray(da.from_array(np.array([[1, 0, 1], [1, 0, 65535]])), dims=['y', 'x'],
                              attrs={'_FillValue': 65535})
        data = xr.DataArray(da.from_array(np.array([[4, 3, 2], [2, 3, 4]], dtype=np.uint8)),
                            dims=['y', 'x'])
        res = self.colormap_composite([data, self.palette, status])

        np.testing.assert_allclose(res, self.exp, atol=1e-4)

    def test_call_dask_with_invalid_value_in_data(self):
        """Test the CloudTopHeight composite generation."""
        status = xr.DataArray(da.from_array(np.array([[1, 0, 1], [1, 0, 1]])), dims=['y', 'x'],
                              attrs={'_FillValue': 65535})
        data = xr.DataArray(da.from_array(np.array([[4, 3, 2], [2, 3, 99]], dtype=np.uint8)),
                            dims=['y', 'x'],
                            attrs={'_FillValue': 99})
        res = self.colormap_composite([data, self.palette, status])

        np.testing.assert_allclose(res, self.exp_all_valid, atol=1e-4)

    def test_call_with_alternative_fill_value_color(self):
        """Test the CloudTopHeight composite generation."""
        status = xr.DataArray(da.from_array(np.array([[1, 0, 1], [1, 0, 1]])), dims=['y', 'x'],
                              attrs={'_FillValue': 65535})
        data = xr.DataArray(da.from_array(np.array([[4, 3, 2], [2, 3, 4]], dtype=np.uint8)),
                            dims=['y', 'x'],
                            attrs={'_FillValue': 99})
        self.palette.attrs['fill_value_color'] = np.array([1, 1, 1])
        res = self.colormap_composite([data, self.palette, status])
        exp = np.array([[[1., 0.498, 1.],
                         [1., 0.498, 1.]],
                        [[1., 0.498, 1.],
                         [1., 0.498, 1.]],
                        [[1., 0.498, 1.],
                         [1., 0.498, 1.]]])
        np.testing.assert_allclose(res, exp, atol=1e-4)


class TestPrecipCloudsCompositor(unittest.TestCase):
    """Test the PrecipClouds compositor."""

    def test_call(self):
        """Test the precip composite generation."""
        from satpy.composites.cloud_products import PrecipCloudsRGB
        colormap_compositor = PrecipCloudsRGB('test_precip_compositor')

        data_light = xr.DataArray(np.array([[80, 70, 60, 0], [20, 30, 40, 255]], dtype=np.uint8),
                                  dims=['y', 'x'], attrs={'_FillValue': 255})
        data_moderate = xr.DataArray(np.array([[60, 50, 40, 0], [20, 30, 40, 255]], dtype=np.uint8),
                                     dims=['y', 'x'], attrs={'_FillValue': 255})
        data_intense = xr.DataArray(np.array([[40, 30, 20, 0], [20, 30, 40, 255]], dtype=np.uint8),
                                    dims=['y', 'x'], attrs={'_FillValue': 255})
        data_flags = xr.DataArray(np.array([[0, 0, 4, 0], [0, 0, 0, 0]], dtype=np.uint8),
                                  dims=['y', 'x'])
        res = colormap_compositor([data_light, data_moderate, data_intense, data_flags])

        exp = np.array([[[0.24313725, 0.18235294, 0.12156863, np.nan],
                         [0.12156863, 0.18235294, 0.24313725, np.nan]],
                        [[0.62184874, 0.51820728, 0.41456583, np.nan],
                         [0.20728291, 0.31092437, 0.41456583, np.nan]],
                        [[0.82913165, 0.7254902, 0.62184874, np.nan],
                         [0.20728291, 0.31092437, 0.41456583, np.nan]]])

        np.testing.assert_allclose(res, exp)


class TestSingleBandCompositor(unittest.TestCase):
    """Test the single-band compositor."""

    def setUp(self):
        """Create test data."""
        from satpy.composites import SingleBandCompositor
        self.comp = SingleBandCompositor(name='test')

        all_valid = np.ones((2, 2))
        self.all_valid = xr.DataArray(all_valid, dims=['y', 'x'])

    def test_call(self):
        """Test calling the compositor."""
        # Dataset with extra attributes
        all_valid = self.all_valid
        all_valid.attrs['sensor'] = 'foo'
        attrs = {
            'foo': 'bar',
            'resolution': 333,
            'units': 'K',
            'sensor': {'fake_sensor1', 'fake_sensor2'},
            'calibration': 'BT',
            'wavelength': 10.8
        }
        self.comp.attrs['resolution'] = None
        res = self.comp([all_valid], **attrs)
        # Verify attributes
        self.assertEqual(res.attrs.get('sensor'), 'foo')
        self.assertTrue('foo' in res.attrs)
        self.assertEqual(res.attrs.get('foo'), 'bar')
        self.assertTrue('units' in res.attrs)
        self.assertTrue('calibration' in res.attrs)
        self.assertFalse('modifiers' in res.attrs)
        self.assertEqual(res.attrs['wavelength'], 10.8)
        self.assertEqual(res.attrs['resolution'], 333)


class TestCategoricalDataCompositor(unittest.TestCase):
    """Test composiotor for recategorization of categorical data."""

    def setUp(self):
        """Create test data."""
        attrs = {'name': 'foo'}
        data = xr.DataArray(da.from_array([[2., 1.], [3., 0.]]), attrs=attrs,
                            dims=('y', 'x'), coords={'y': [0, 1], 'x': [0, 1]})

        self.data = data

    def test_basic_recategorization(self):
        """Test general functionality of compositor incl. attributes."""
        from satpy.composites import CategoricalDataCompositor
        lut = [np.nan, 0, 1, 1]
        name = 'bar'
        comp = CategoricalDataCompositor(name=name, lut=lut)
        res = comp([self.data])
        res = res.compute()
        expected = np.array([[1., 0.], [1., np.nan]])
        np.testing.assert_equal(res.values, expected)
        np.testing.assert_equal(res.attrs['name'], name)
        np.testing.assert_equal(res.attrs['composite_lut'], lut)

    def test_too_many_datasets(self):
        """Test that ValueError is raised if more than one dataset is provided."""
        from satpy.composites import CategoricalDataCompositor
        lut = [np.nan, 0, 1, 1]
        comp = CategoricalDataCompositor(name='foo', lut=lut)
        np.testing.assert_raises(ValueError, comp, [self.data, self.data])


class TestGenericCompositor(unittest.TestCase):
    """Test generic compositor."""

    def setUp(self):
        """Create test data."""
        from satpy.composites import GenericCompositor
        self.comp = GenericCompositor(name='test')
        self.comp2 = GenericCompositor(name='test2', common_channel_mask=False)

        all_valid = np.ones((1, 2, 2))
        self.all_valid = xr.DataArray(all_valid, dims=['bands', 'y', 'x'])
        first_invalid = np.reshape(np.array([np.nan, 1., 1., 1.]), (1, 2, 2))
        self.first_invalid = xr.DataArray(first_invalid,
                                          dims=['bands', 'y', 'x'])
        second_invalid = np.reshape(np.array([1., np.nan, 1., 1.]), (1, 2, 2))
        self.second_invalid = xr.DataArray(second_invalid,
                                           dims=['bands', 'y', 'x'])
        wrong_shape = np.reshape(np.array([1., 1., 1.]), (1, 3, 1))
        self.wrong_shape = xr.DataArray(wrong_shape, dims=['bands', 'y', 'x'])

    def test_masking(self):
        """Test masking in generic compositor."""
        # Single channel
        res = self.comp([self.all_valid])
        np.testing.assert_allclose(res.data, 1., atol=1e-9)
        # Three channels, one value invalid
        res = self.comp([self.all_valid, self.all_valid, self.first_invalid])
        correct = np.reshape(np.array([np.nan, 1., 1., 1.]), (2, 2))
        for i in range(3):
            np.testing.assert_almost_equal(res.data[i, :, :], correct)
        # Three channels, two values invalid
        res = self.comp([self.all_valid, self.first_invalid, self.second_invalid])
        correct = np.reshape(np.array([np.nan, np.nan, 1., 1.]), (2, 2))
        for i in range(3):
            np.testing.assert_almost_equal(res.data[i, :, :], correct)

    def test_concat_datasets(self):
        """Test concatenation of datasets."""
        from satpy.composites import IncompatibleAreas
        res = self.comp._concat_datasets([self.all_valid], 'L')
        num_bands = len(res.bands)
        self.assertEqual(num_bands, 1)
        self.assertEqual(res.shape[0], num_bands)
        self.assertEqual(res.bands[0], 'L')
        res = self.comp._concat_datasets([self.all_valid, self.all_valid], 'LA')
        num_bands = len(res.bands)
        self.assertEqual(num_bands, 2)
        self.assertEqual(res.shape[0], num_bands)
        self.assertEqual(res.bands[0], 'L')
        self.assertEqual(res.bands[1], 'A')
        self.assertRaises(IncompatibleAreas, self.comp._concat_datasets,
                          [self.all_valid, self.wrong_shape], 'LA')

    def test_get_sensors(self):
        """Test getting sensors from the dataset attributes."""
        res = self.comp._get_sensors([self.all_valid])
        self.assertIsNone(res)
        dset1 = self.all_valid
        dset1.attrs['sensor'] = 'foo'
        res = self.comp._get_sensors([dset1])
        self.assertEqual(res, 'foo')
        dset2 = self.first_invalid
        dset2.attrs['sensor'] = 'bar'
        res = self.comp._get_sensors([dset1, dset2])
        self.assertIn('foo', res)
        self.assertIn('bar', res)
        self.assertEqual(len(res), 2)
        self.assertIsInstance(res, set)

    @mock.patch('satpy.composites.GenericCompositor._get_sensors')
    @mock.patch('satpy.composites.combine_metadata')
    @mock.patch('satpy.composites.check_times')
    @mock.patch('satpy.composites.GenericCompositor.match_data_arrays')
    def test_call_with_mock(self, match_data_arrays, check_times, combine_metadata, get_sensors):
        """Test calling generic compositor."""
        from satpy.composites import IncompatibleAreas
        combine_metadata.return_value = dict()
        get_sensors.return_value = 'foo'
        # One dataset, no mode given
        res = self.comp([self.all_valid])
        self.assertEqual(res.shape[0], 1)
        self.assertEqual(res.attrs['mode'], 'L')
        match_data_arrays.assert_not_called()
        # This compositor has been initialized without common masking, so the
        # masking shouldn't have been called
        projectables = [self.all_valid, self.first_invalid, self.second_invalid]
        match_data_arrays.return_value = projectables
        res = self.comp2(projectables)
        match_data_arrays.assert_called_once()
        match_data_arrays.reset_mock()
        # Dataset for alpha given, so shouldn't be masked
        projectables = [self.all_valid, self.all_valid]
        match_data_arrays.return_value = projectables
        res = self.comp(projectables)
        match_data_arrays.assert_called_once()
        match_data_arrays.reset_mock()
        # When areas are incompatible, masking shouldn't happen
        match_data_arrays.side_effect = IncompatibleAreas()
        self.assertRaises(IncompatibleAreas,
                          self.comp, [self.all_valid, self.wrong_shape])
        match_data_arrays.assert_called_once()

    def test_call(self):
        """Test calling generic compositor."""
        # Multiple datasets with extra attributes
        all_valid = self.all_valid
        all_valid.attrs['sensor'] = 'foo'
        attrs = {'foo': 'bar', 'resolution': 333}
        self.comp.attrs['resolution'] = None
        res = self.comp([self.all_valid, self.first_invalid], **attrs)
        # Verify attributes
        self.assertEqual(res.attrs.get('sensor'), 'foo')
        self.assertIn('foo', res.attrs)
        self.assertEqual(res.attrs.get('foo'), 'bar')
        self.assertNotIn('units', res.attrs)
        self.assertNotIn('calibration', res.attrs)
        self.assertNotIn('modifiers', res.attrs)
        self.assertIsNone(res.attrs['wavelength'])
        self.assertEqual(res.attrs['mode'], 'LA')
        self.assertEqual(res.attrs['resolution'], 333)


class TestAddBands(unittest.TestCase):
    """Test case for the `add_bands` function."""

    def test_add_bands_l_rgb(self):
        """Test adding bands."""
        from satpy.composites import add_bands

        # L + RGB -> RGB
        data = xr.DataArray(da.ones((1, 3, 3)), dims=('bands', 'y', 'x'),
                            coords={'bands': ['L']})
        new_bands = xr.DataArray(da.array(['R', 'G', 'B']), dims=('bands'),
                                 coords={'bands': ['R', 'G', 'B']})
        res = add_bands(data, new_bands)
        res_bands = ['R', 'G', 'B']
        self.assertEqual(res.attrs['mode'], ''.join(res_bands))
        np.testing.assert_array_equal(res.bands, res_bands)
        np.testing.assert_array_equal(res.coords['bands'], res_bands)

    def test_add_bands_l_rgba(self):
        """Test adding bands."""
        from satpy.composites import add_bands

        # L + RGBA -> RGBA
        data = xr.DataArray(da.ones((1, 3, 3)), dims=('bands', 'y', 'x'),
                            coords={'bands': ['L']}, attrs={'mode': 'L'})
        new_bands = xr.DataArray(da.array(['R', 'G', 'B', 'A']), dims=('bands'),
                                 coords={'bands': ['R', 'G', 'B', 'A']})
        res = add_bands(data, new_bands)
        res_bands = ['R', 'G', 'B', 'A']
        self.assertEqual(res.attrs['mode'], ''.join(res_bands))
        np.testing.assert_array_equal(res.bands, res_bands)
        np.testing.assert_array_equal(res.coords['bands'], res_bands)

    def test_add_bands_la_rgb(self):
        """Test adding bands."""
        from satpy.composites import add_bands

        # LA + RGB -> RGBA
        data = xr.DataArray(da.ones((2, 3, 3)), dims=('bands', 'y', 'x'),
                            coords={'bands': ['L', 'A']}, attrs={'mode': 'LA'})
        new_bands = xr.DataArray(da.array(['R', 'G', 'B']), dims=('bands'),
                                 coords={'bands': ['R', 'G', 'B']})
        res = add_bands(data, new_bands)
        res_bands = ['R', 'G', 'B', 'A']
        self.assertEqual(res.attrs['mode'], ''.join(res_bands))
        np.testing.assert_array_equal(res.bands, res_bands)
        np.testing.assert_array_equal(res.coords['bands'], res_bands)

    def test_add_bands_rgb_rbga(self):
        """Test adding bands."""
        from satpy.composites import add_bands

        # RGB + RGBA -> RGBA
        data = xr.DataArray(da.ones((3, 3, 3)), dims=('bands', 'y', 'x'),
                            coords={'bands': ['R', 'G', 'B']},
                            attrs={'mode': 'RGB'})
        new_bands = xr.DataArray(da.array(['R', 'G', 'B', 'A']), dims=('bands'),
                                 coords={'bands': ['R', 'G', 'B', 'A']})
        res = add_bands(data, new_bands)
        res_bands = ['R', 'G', 'B', 'A']
        self.assertEqual(res.attrs['mode'], ''.join(res_bands))
        np.testing.assert_array_equal(res.bands, res_bands)
        np.testing.assert_array_equal(res.coords['bands'], res_bands)

    def test_add_bands_p_l(self):
        """Test adding bands."""
        from satpy.composites import add_bands

        # P(RGBA) + L -> RGBA
        data = xr.DataArray(da.ones((1, 3, 3)), dims=('bands', 'y', 'x'),
                            coords={'bands': ['P']},
                            attrs={'mode': 'P'})
        new_bands = xr.DataArray(da.array(['L']), dims=('bands'),
                                 coords={'bands': ['L']})
        with pytest.raises(NotImplementedError):
            add_bands(data, new_bands)


class TestStaticImageCompositor(unittest.TestCase):
    """Test case for the static compositor."""

    @mock.patch('satpy.resample.get_area_def')
    def test_init(self, get_area_def):
        """Test the initializiation of static compositor."""
        from satpy.composites import StaticImageCompositor

        # No filename given raises ValueError
        with self.assertRaises(ValueError):
            StaticImageCompositor("name")

        # No area defined
        comp = StaticImageCompositor("name", filename="/foo.tif")
        self.assertEqual(comp._cache_filename, "/foo.tif")
        self.assertIsNone(comp.area)

        # Area defined
        get_area_def.return_value = "bar"
        comp = StaticImageCompositor("name", filename="/foo.tif", area="euro4")
        self.assertEqual(comp._cache_filename, "/foo.tif")
        self.assertEqual(comp.area, "bar")
        get_area_def.assert_called_once_with("euro4")

    @mock.patch('satpy.aux_download.retrieve')
    @mock.patch('satpy.aux_download.register_file')
    @mock.patch('satpy.Scene')
    def test_call(self, Scene, register, retrieve):  # noqa
        """Test the static compositing."""
        from satpy.composites import StaticImageCompositor

        satpy.config.set(data_dir=os.path.join(os.path.sep, 'path', 'to', 'image'))
        remote_tif = "http://example.com/foo.tif"

        class MockScene(dict):
            def load(self, arg):
                pass

        img = mock.MagicMock()
        img.attrs = {}
        scn = MockScene()
        scn['image'] = img
        Scene.return_value = scn
        # absolute path to local file
        comp = StaticImageCompositor("name", filename="/foo.tif", area="euro4")
        res = comp()
        Scene.assert_called_once_with(reader='generic_image',
                                      filenames=['/foo.tif'])
        register.assert_not_called()
        retrieve.assert_not_called()
        self.assertIn("start_time", res.attrs)
        self.assertIn("end_time", res.attrs)
        self.assertIsNone(res.attrs['sensor'])
        self.assertNotIn('modifiers', res.attrs)
        self.assertNotIn('calibration', res.attrs)

        # remote file with local cached version
        Scene.reset_mock()
        register.return_value = "data_dir/foo.tif"
        retrieve.return_value = "data_dir/foo.tif"
        comp = StaticImageCompositor("name", url=remote_tif, area="euro4")
        res = comp()
        Scene.assert_called_once_with(reader='generic_image',
                                      filenames=['data_dir/foo.tif'])
        self.assertIn("start_time", res.attrs)
        self.assertIn("end_time", res.attrs)
        self.assertIsNone(res.attrs['sensor'])
        self.assertNotIn('modifiers', res.attrs)
        self.assertNotIn('calibration', res.attrs)

        # Non-georeferenced image, no area given
        img.attrs.pop('area')
        comp = StaticImageCompositor("name", filename="/foo.tif")
        with self.assertRaises(AttributeError):
            comp()

        # Non-georeferenced image, area given
        comp = StaticImageCompositor("name", filename="/foo.tif", area='euro4')
        res = comp()
        self.assertEqual(res.attrs['area'].area_id, 'euro4')

        # Filename contains environment variable
        os.environ["TEST_IMAGE_PATH"] = "/path/to/image"
        comp = StaticImageCompositor("name", filename="${TEST_IMAGE_PATH}/foo.tif", area='euro4')
        self.assertEqual(comp._cache_filename, "/path/to/image/foo.tif")

        # URL and filename without absolute path
        comp = StaticImageCompositor("name", url=remote_tif, filename="bar.tif")
        self.assertEqual(comp._url, remote_tif)
        self.assertEqual(comp._cache_filename, "bar.tif")

        # No URL, filename without absolute path, use default data_dir from config
        with mock.patch('os.path.exists') as exists:
            exists.return_value = True
            comp = StaticImageCompositor("name", filename="foo.tif")
            self.assertEqual(comp._url, None)
            self.assertEqual(comp._cache_filename,
                             os.path.join(os.path.sep, 'path', 'to', 'image', 'foo.tif'))


def _enhance2dataset(dataset, convert_p=False):
    """Mock the enhance2dataset to return the original data."""
    return dataset


class TestBackgroundCompositor:
    """Test case for the background compositor."""

    @classmethod
    def setup_class(cls):
        """Create shared input data arrays."""
        foreground_data = {
            "L": np.array([[[1., 0.5], [0., np.nan]]]),
            "LA": np.array([[[1., 0.5], [0., np.nan]], [[0.5, 0.5], [0.5, 0.5]]]),
            "RGB": np.array([
                [[1., 0.5], [0., np.nan]],
                [[1., 0.5], [0., np.nan]],
                [[1., 0.5], [0., np.nan]]]),
            "RGBA": np.array([
                [[1.0, 0.5], [0.0, np.nan]],
                [[1.0, 0.5], [0.0, np.nan]],
                [[1.0, 0.5], [0.0, np.nan]],
                [[0.5, 0.5], [0.5, 0.5]]]),
        }
        cls.foreground_data = foreground_data

    @mock.patch('satpy.composites.enhance2dataset', _enhance2dataset)
    @pytest.mark.parametrize(
        ('foreground_bands', 'background_bands', 'exp_bands', 'exp_result'),
        [
            ('L', 'L', 'L', np.array([[1.0, 0.5], [0.0, 1.0]])),
            ('LA', 'LA', 'L', np.array([[1.0, 0.75], [0.5, 1.0]])),
            ('RGB', 'RGB', 'RGB', np.array([
                [[1., 0.5], [0., 1.]],
                [[1., 0.5], [0., 1.]],
                [[1., 0.5], [0., 1.]]])),
            ('RGBA', 'RGBA', 'RGB', np.array([
                [[1., 0.75], [0.5, 1.]],
                [[1., 0.75], [0.5, 1.]],
                [[1., 0.75], [0.5, 1.]]])),
            ('RGBA', 'RGB', 'RGB', np.array([
                [[1., 0.75], [0.5, 1.]],
                [[1., 0.75], [0.5, 1.]],
                [[1., 0.75], [0.5, 1.]]])),
        ]
    )
    def test_call(self, foreground_bands, background_bands, exp_bands, exp_result):
        """Test the background compositing."""
        from satpy.composites import BackgroundCompositor
        comp = BackgroundCompositor("name")

        # L mode images
        foreground_data = self.foreground_data[foreground_bands]
        attrs = {'mode': foreground_bands, 'area': 'foo'}
        foreground = xr.DataArray(da.from_array(foreground_data),
                                  dims=('bands', 'y', 'x'),
                                  coords={'bands': [c for c in attrs['mode']]},
                                  attrs=attrs)
        attrs = {'mode': background_bands, 'area': 'foo'}
        background = xr.DataArray(da.ones((len(background_bands), 2, 2)), dims=('bands', 'y', 'x'),
                                  coords={'bands': [c for c in attrs['mode']]},
                                  attrs=attrs)
        res = comp([foreground, background])
        assert res.attrs['area'] == 'foo'
        np.testing.assert_allclose(res, exp_result)
        assert res.attrs['mode'] == exp_bands

    @mock.patch('satpy.composites.enhance2dataset', _enhance2dataset)
    def test_multiple_sensors(self):
        """Test the background compositing from multiple sensor data."""
        from satpy.composites import BackgroundCompositor
        comp = BackgroundCompositor("name")

        # L mode images
        attrs = {'mode': 'L', 'area': 'foo'}
        foreground_data = self.foreground_data["L"]
        foreground = xr.DataArray(da.from_array(foreground_data),
                                  dims=('bands', 'y', 'x'),
                                  coords={'bands': [c for c in attrs['mode']]},
                                  attrs=attrs.copy())
        foreground.attrs['sensor'] = 'abi'
        background = xr.DataArray(da.ones((1, 2, 2)), dims=('bands', 'y', 'x'),
                                  coords={'bands': [c for c in attrs['mode']]},
                                  attrs=attrs.copy())
        background.attrs['sensor'] = 'glm'
        res = comp([foreground, background])
        assert res.attrs['area'] == 'foo'
        np.testing.assert_allclose(res, np.array([[1., 0.5], [0., 1.]]))
        assert res.attrs['mode'] == 'L'
        assert res.attrs['sensor'] == {'abi', 'glm'}


class TestMaskingCompositor:
    """Test case for the simple masking compositor."""

    @pytest.fixture
    def conditions_v1(self):
        """Masking conditions with string values."""
        return [{'method': 'equal',
                 'value': 'Cloud-free_land',
                 'transparency': 100},
                {'method': 'equal',
                 'value': 'Cloud-free_sea',
                 'transparency': 50}]

    @pytest.fixture
    def conditions_v2(self):
        """Masking conditions with numerical values."""
        return [{'method': 'equal',
                 'value': 1,
                 'transparency': 100},
                {'method': 'equal',
                 'value': 2,
                 'transparency': 50}]

    @pytest.fixture
    def test_data(self):
        """Test data to use with masking compositors."""
        return xr.DataArray(da.random.random((3, 3)), dims=['y', 'x'])

    @pytest.fixture
    def test_ct_data(self):
        """Test 2D CT data array."""
        flag_meanings = ['Cloud-free_land', 'Cloud-free_sea']
        flag_values = da.array([1, 2])
        ct_data = da.array([[1, 2, 2],
                            [2, 1, 2],
                            [2, 2, 1]])
        ct_data = xr.DataArray(ct_data, dims=['y', 'x'])
        ct_data.attrs['flag_meanings'] = flag_meanings
        ct_data.attrs['flag_values'] = flag_values
        return ct_data

    @pytest.fixture
    def test_ct_data_v3(self, test_ct_data):
        """Set ct data to NaN where it originally is 1."""
        return test_ct_data.where(test_ct_data == 1)

    @pytest.fixture
    def reference_data(self, test_data, test_ct_data):
        """Get reference data to use in masking compositor tests."""
        # The data are set to NaN where ct is `1`
        return test_data.where(test_ct_data > 1)

    @pytest.fixture
    def reference_alpha(self):
        """Get reference alpha to use in masking compositor tests."""
        ref_alpha = da.array([[0, 0.5, 0.5],
                              [0.5, 0, 0.5],
                              [0.5, 0.5, 0]])
        return xr.DataArray(ref_alpha, dims=['y', 'x'])

    def test_init(self):
        """Test the initializiation of compositor."""
        from satpy.composites import MaskingCompositor

        # No transparency or conditions given raises ValueError
        with pytest.raises(ValueError):
            comp = MaskingCompositor("name")

        # transparency defined
        transparency = {0: 100, 1: 50}
        conditions = [{'method': 'equal', 'value': 0, 'transparency': 100},
                      {'method': 'equal', 'value': 1, 'transparency': 50}]
        comp = MaskingCompositor("name", transparency=transparency.copy())
        assert not hasattr(comp, 'transparency')
        # Transparency should be converted to conditions
        assert comp.conditions == conditions

        # conditions defined
        comp = MaskingCompositor("name", conditions=conditions.copy())
        assert comp.conditions == conditions

    def test_get_flag_value(self):
        """Test reading flag value from attributes based on a name."""
        from satpy.composites import _get_flag_value

        flag_values = da.array([1, 2])
        mask = da.array([[1, 2, 2],
                         [2, 1, 2],
                         [2, 2, 1]])
        mask = xr.DataArray(mask, dims=['y', 'x'])
        flag_meanings = ['Cloud-free_land', 'Cloud-free_sea']
        mask.attrs['flag_meanings'] = flag_meanings
        mask.attrs['flag_values'] = flag_values

        assert _get_flag_value(mask, 'Cloud-free_land') == 1
        assert _get_flag_value(mask, 'Cloud-free_sea') == 2

        flag_meanings_str = 'Cloud-free_land Cloud-free_sea'
        mask.attrs['flag_meanings'] = flag_meanings_str
        assert _get_flag_value(mask, 'Cloud-free_land') == 1
        assert _get_flag_value(mask, 'Cloud-free_sea') == 2

    @pytest.mark.parametrize("mode", ["LA", "RGBA"])
    def test_call_numerical_transparency_data(
            self, conditions_v1, test_data, test_ct_data, reference_data,
            reference_alpha, mode):
        """Test call the compositor with numerical transparency data.

        Use parameterisation to test different image modes.
        """
        from satpy.composites import MaskingCompositor
        from satpy.tests.utils import CustomScheduler

        # Test with numerical transparency data
        with dask.config.set(scheduler=CustomScheduler(max_computes=0)):
            comp = MaskingCompositor("name", conditions=conditions_v1,
                                     mode=mode)
            res = comp([test_data, test_ct_data])
        assert res.mode == mode
        for m in mode.rstrip("A"):
            np.testing.assert_allclose(res.sel(bands=m), reference_data)
        np.testing.assert_allclose(res.sel(bands='A'), reference_alpha)

    def test_call_named_fields(self, conditions_v2, test_data, test_ct_data,
                               reference_data, reference_alpha):
        """Test with named fields."""
        from satpy.composites import MaskingCompositor
        from satpy.tests.utils import CustomScheduler

        with dask.config.set(scheduler=CustomScheduler(max_computes=0)):
            comp = MaskingCompositor("name", conditions=conditions_v2)
            res = comp([test_data, test_ct_data])
        assert res.mode == "LA"
        np.testing.assert_allclose(res.sel(bands='L'), reference_data)
        np.testing.assert_allclose(res.sel(bands='A'), reference_alpha)

    def test_call_named_fields_string(
            self, conditions_v2, test_data, test_ct_data, reference_data,
            reference_alpha):
        """Test with named fields which are as a string in the mask attributes."""
        from satpy.composites import MaskingCompositor
        from satpy.tests.utils import CustomScheduler

        flag_meanings_str = 'Cloud-free_land Cloud-free_sea'
        test_ct_data.attrs['flag_meanings'] = flag_meanings_str
        with dask.config.set(scheduler=CustomScheduler(max_computes=0)):
            comp = MaskingCompositor("name", conditions=conditions_v2)
            res = comp([test_data, test_ct_data])
        assert res.mode == "LA"
        np.testing.assert_allclose(res.sel(bands='L'), reference_data)
        np.testing.assert_allclose(res.sel(bands='A'), reference_alpha)

    def test_method_isnan(self, test_data,
                          test_ct_data, test_ct_data_v3):
        """Test "isnan" as method."""
        from satpy.composites import MaskingCompositor
        from satpy.tests.utils import CustomScheduler

        conditions_v3 = [{'method': 'isnan', 'transparency': 100}]

        # The data are set to NaN where ct is NaN
        reference_data_v3 = test_data.where(test_ct_data == 1)
        reference_alpha_v3 = da.array([[1., 0., 0.],
                                       [0., 1., 0.],
                                       [0., 0., 1.]])
        reference_alpha_v3 = xr.DataArray(reference_alpha_v3, dims=['y', 'x'])
        with dask.config.set(scheduler=CustomScheduler(max_computes=0)):
            comp = MaskingCompositor("name", conditions=conditions_v3)
            res = comp([test_data, test_ct_data_v3])
        assert res.mode == "LA"
        np.testing.assert_allclose(res.sel(bands='L'), reference_data_v3)
        np.testing.assert_allclose(res.sel(bands='A'), reference_alpha_v3)

    def test_method_absolute_import(self, test_data, test_ct_data_v3):
        """Test "absolute_import" as method."""
        from satpy.composites import MaskingCompositor
        from satpy.tests.utils import CustomScheduler

        conditions_v4 = [{'method': 'absolute_import', 'transparency': 'satpy.resample'}]
        # This should raise AttributeError
        with dask.config.set(scheduler=CustomScheduler(max_computes=0)):
            comp = MaskingCompositor("name", conditions=conditions_v4)
            with pytest.raises(AttributeError):
                comp([test_data, test_ct_data_v3])

    def test_rgb_dataset(self, conditions_v1, test_ct_data, reference_alpha):
        """Test RGB dataset."""
        from satpy.composites import MaskingCompositor
        from satpy.tests.utils import CustomScheduler

        # 3D data array
        data = xr.DataArray(da.random.random((3, 3, 3)),
                            dims=['bands', 'y', 'x'],
                            coords={'bands': ['R', 'G', 'B'],
                                    'y': np.arange(3),
                                    'x': np.arange(3)})

        with dask.config.set(scheduler=CustomScheduler(max_computes=0)):
            comp = MaskingCompositor("name", conditions=conditions_v1)
            res = comp([data, test_ct_data])
        assert res.mode == "RGBA"
        np.testing.assert_allclose(res.sel(bands='R'),
                                   data.sel(bands='R').where(test_ct_data > 1))
        np.testing.assert_allclose(res.sel(bands='G'),
                                   data.sel(bands='G').where(test_ct_data > 1))
        np.testing.assert_allclose(res.sel(bands='B'),
                                   data.sel(bands='B').where(test_ct_data > 1))
        np.testing.assert_allclose(res.sel(bands='A'), reference_alpha)

    def test_rgba_dataset(self, conditions_v2, test_ct_data, reference_alpha):
        """Test RGBA dataset."""
        from satpy.composites import MaskingCompositor
        from satpy.tests.utils import CustomScheduler
        data = xr.DataArray(da.random.random((4, 3, 3)),
                            dims=['bands', 'y', 'x'],
                            coords={'bands': ['R', 'G', 'B', 'A'],
                                    'y': np.arange(3),
                                    'x': np.arange(3)})

        with dask.config.set(scheduler=CustomScheduler(max_computes=0)):
            comp = MaskingCompositor("name", conditions=conditions_v2)
            res = comp([data, test_ct_data])
        assert res.mode == "RGBA"
        np.testing.assert_allclose(res.sel(bands='R'),
                                   data.sel(bands='R').where(test_ct_data > 1))
        np.testing.assert_allclose(res.sel(bands='G'),
                                   data.sel(bands='G').where(test_ct_data > 1))
        np.testing.assert_allclose(res.sel(bands='B'),
                                   data.sel(bands='B').where(test_ct_data > 1))
        # The compositor should drop the original alpha band
        np.testing.assert_allclose(res.sel(bands='A'), reference_alpha)

    def test_incorrect_method(self, test_data, test_ct_data):
        """Test incorrect method."""
        from satpy.composites import MaskingCompositor
        conditions = [{'method': 'foo', 'value': 0, 'transparency': 100}]
        comp = MaskingCompositor("name", conditions=conditions)
        with pytest.raises(AttributeError):
            comp([test_data, test_ct_data])
        # Test with too few projectables.
        with pytest.raises(ValueError):
            comp([test_data])

    def test_incorrect_mode(self, conditions_v1):
        """Test initiating with unsupported mode."""
        from satpy.composites import MaskingCompositor

        # Incorrect mode raises ValueError
        with pytest.raises(ValueError):
            MaskingCompositor("name", conditions=conditions_v1,
                              mode="YCbCrA")


class TestNaturalEnhCompositor(unittest.TestCase):
    """Test NaturalEnh compositor."""

    def setUp(self):
        """Create channel data and set channel weights."""
        self.ch1 = xr.DataArray([1.0])
        self.ch2 = xr.DataArray([2.0])
        self.ch3 = xr.DataArray([3.0])
        self.ch16_w = 2.0
        self.ch08_w = 3.0
        self.ch06_w = 4.0

    @mock.patch('satpy.composites.NaturalEnh.__repr__')
    @mock.patch('satpy.composites.NaturalEnh.match_data_arrays')
    def test_natural_enh(self, match_data_arrays, repr_):
        """Test NaturalEnh compositor."""
        from satpy.composites import NaturalEnh
        repr_.return_value = ''
        projectables = [self.ch1, self.ch2, self.ch3]

        def temp_func(*args):
            return args[0]

        match_data_arrays.side_effect = temp_func
        comp = NaturalEnh("foo", ch16_w=self.ch16_w, ch08_w=self.ch08_w,
                          ch06_w=self.ch06_w)
        self.assertEqual(comp.ch16_w, self.ch16_w)
        self.assertEqual(comp.ch08_w, self.ch08_w)
        self.assertEqual(comp.ch06_w, self.ch06_w)
        res = comp(projectables)
        assert mock.call(projectables) in match_data_arrays.mock_calls
        correct = (self.ch16_w * projectables[0] +
                   self.ch08_w * projectables[1] +
                   self.ch06_w * projectables[2])
        self.assertEqual(res[0], correct)
        self.assertEqual(res[1], projectables[1])
        self.assertEqual(res[2], projectables[2])


class TestEnhance2Dataset(unittest.TestCase):
    """Test the enhance2dataset utility."""

    @mock.patch('satpy.composites.get_enhanced_image')
    def test_enhance_p_to_rgb(self, get_enhanced_image):
        """Test enhancing a paletted dataset in RGB mode."""
        from trollimage.xrimage import XRImage
        img = XRImage(xr.DataArray(np.ones((1, 20, 20)) * 2, dims=('bands', 'y', 'x'), coords={'bands': ['P']}))
        img.palette = ((0, 0, 0), (4, 4, 4), (8, 8, 8))
        get_enhanced_image.return_value = img

        from satpy.composites import enhance2dataset
        dataset = xr.DataArray(np.ones((1, 20, 20)))
        res = enhance2dataset(dataset, convert_p=True)
        assert res.attrs['mode'] == 'RGB'

    @mock.patch('satpy.composites.get_enhanced_image')
    def test_enhance_p_to_rgba(self, get_enhanced_image):
        """Test enhancing a paletted dataset in RGBA mode."""
        from trollimage.xrimage import XRImage
        img = XRImage(xr.DataArray(np.ones((1, 20, 20)) * 2, dims=('bands', 'y', 'x'), coords={'bands': ['P']}))
        img.palette = ((0, 0, 0, 255), (4, 4, 4, 255), (8, 8, 8, 255))
        get_enhanced_image.return_value = img

        from satpy.composites import enhance2dataset
        dataset = xr.DataArray(np.ones((1, 20, 20)))
        res = enhance2dataset(dataset, convert_p=True)
        assert res.attrs['mode'] == 'RGBA'

    @mock.patch('satpy.composites.get_enhanced_image')
    def test_enhance_p(self, get_enhanced_image):
        """Test enhancing a paletted dataset in P mode."""
        from trollimage.xrimage import XRImage
        img = XRImage(xr.DataArray(np.ones((1, 20, 20)) * 2, dims=('bands', 'y', 'x'), coords={'bands': ['P']}))
        img.palette = ((0, 0, 0, 255), (4, 4, 4, 255), (8, 8, 8, 255))
        get_enhanced_image.return_value = img

        from satpy.composites import enhance2dataset
        dataset = xr.DataArray(np.ones((1, 20, 20)))
        res = enhance2dataset(dataset)
        assert res.attrs['mode'] == 'P'
        assert res.max().values == 2

    @mock.patch('satpy.composites.get_enhanced_image')
    def test_enhance_l(self, get_enhanced_image):
        """Test enhancing a paletted dataset in P mode."""
        from trollimage.xrimage import XRImage
        img = XRImage(xr.DataArray(np.ones((1, 20, 20)) * 2, dims=('bands', 'y', 'x'), coords={'bands': ['L']}))
        get_enhanced_image.return_value = img

        from satpy.composites import enhance2dataset
        dataset = xr.DataArray(np.ones((1, 20, 20)))
        res = enhance2dataset(dataset)
        assert res.attrs['mode'] == 'L'
        assert res.max().values == 1


class TestInferMode(unittest.TestCase):
    """Test the infer_mode utility."""

    def test_bands_coords_is_used(self):
        """Test that the `bands` coord is used."""
        from satpy.composites import GenericCompositor
        arr = xr.DataArray(np.ones((1, 5, 5)), dims=('bands', 'x', 'y'), coords={'bands': ['P']})
        assert GenericCompositor.infer_mode(arr) == 'P'

        arr = xr.DataArray(np.ones((3, 5, 5)), dims=('bands', 'x', 'y'), coords={'bands': ['Y', 'Cb', 'Cr']})
        assert GenericCompositor.infer_mode(arr) == 'YCbCr'

    def test_mode_is_used(self):
        """Test that the `mode` attribute is used."""
        from satpy.composites import GenericCompositor
        arr = xr.DataArray(np.ones((1, 5, 5)), dims=('bands', 'x', 'y'), attrs={'mode': 'P'})
        assert GenericCompositor.infer_mode(arr) == 'P'

    def test_band_size_is_used(self):
        """Test that the band size is used."""
        from satpy.composites import GenericCompositor
        arr = xr.DataArray(np.ones((2, 5, 5)), dims=('bands', 'x', 'y'))
        assert GenericCompositor.infer_mode(arr) == 'LA'

    def test_no_bands_is_l(self):
        """Test that default (no band) is L."""
        from satpy.composites import GenericCompositor
        arr = xr.DataArray(np.ones((5, 5)), dims=('x', 'y'))
        assert GenericCompositor.infer_mode(arr) == 'L'


class TestLongitudeMaskingCompositor(unittest.TestCase):
    """Test case for the LongitudeMaskingCompositor compositor."""

    def test_masking(self):
        """Test longitude masking."""
        from satpy.composites import LongitudeMaskingCompositor

        area = mock.MagicMock()
        lons = np.array([-180., -100., -50., 0., 50., 100., 180.])
        area.get_lonlats = mock.MagicMock(return_value=[lons, []])
        a = xr.DataArray(np.array([1, 2, 3, 4, 5, 6, 7]),
                         attrs={'area': area, 'units': 'K'})

        comp = LongitudeMaskingCompositor(name='test', lon_min=-40., lon_max=120.)
        expected = xr.DataArray(np.array([np.nan, np.nan, np.nan, 4, 5, 6, np.nan]))
        res = comp([a])
        np.testing.assert_allclose(res.data, expected.data)
        assert "units" in res.attrs
        assert res.attrs["units"] == "K"

        comp = LongitudeMaskingCompositor(name='test', lon_min=-40.)
        expected = xr.DataArray(np.array([np.nan, np.nan, np.nan, 4, 5, 6, 7]))
        res = comp([a])
        np.testing.assert_allclose(res.data, expected.data)

        comp = LongitudeMaskingCompositor(name='test', lon_max=120.)
        expected = xr.DataArray(np.array([1, 2, 3, 4, 5, 6, np.nan]))
        res = comp([a])
        np.testing.assert_allclose(res.data, expected.data)

        comp = LongitudeMaskingCompositor(name='test', lon_min=120., lon_max=-40.)
        expected = xr.DataArray(np.array([1, 2, 3, np.nan, np.nan, np.nan, 7]))
        res = comp([a])
        np.testing.assert_allclose(res.data, expected.data)


def test_bad_sensor_yaml_configs(tmp_path):
    """Test composite YAML file with no sensor isn't loaded.

    But the bad YAML also shouldn't crash composite configuration loading.

    """
    from satpy.composites.config_loader import load_compositor_configs_for_sensors

    comp_dir = tmp_path / "composites"
    comp_dir.mkdir()
    comp_yaml = comp_dir / "fake_sensor.yaml"
    with satpy.config.set(config_path=[tmp_path]):
        _create_fake_composite_config(comp_yaml)

        # no sensor_name in YAML, quietly ignored
        comps, _ = load_compositor_configs_for_sensors(["fake_sensor"])
        assert "fake_sensor" in comps
        assert "fake_composite" not in comps["fake_sensor"]


def _create_fake_composite_config(yaml_filename: str):
    import yaml

    from satpy.composites import StaticImageCompositor

    with open(yaml_filename, "w") as comp_file:
        yaml.dump({
            "composites": {
                "fake_composite": {
                    "compositor": StaticImageCompositor,
                    "url": "http://example.com/image.png",
                },
            },
        },
            comp_file,
        )