[map branch] Add simple submap vs slice test

sunpy/map/tests/test_mapbase.py

@@ -27,6 +27,7 @@
 import sunpy.coordinates
 import sunpy.map
 import sunpy.sun
+from ndcube.tests.helpers import assert_cubes_equal
 from sunpy.coordinates import HeliographicCarrington, HeliographicStonyhurst, sun
 from sunpy.data.test import get_dummy_map_from_header, get_test_filepath
 from sunpy.image.transform import _rotation_registry
@@ -1866,3 +1867,21 @@
                                                               aia171_test_map.meta["CRPIX2"])
 
     assert np.allclose(sliced_ref_coord, ori_ref_coord)
+
+def test_slicing_map_submap_same(aia171_test_map):
+    bl_coord = SkyCoord(-1000 * u.arcsec, 0 * u.arcsec, frame=aia171_test_map.coordinate_frame)
+    bottom_left = aia171_test_map.wcs.world_to_pixel(bl_coord)
+
+    tp_coord = SkyCoord(0 * u.arcsec, 1000 * u.arcsec, frame=aia171_test_map.coordinate_frame)
+    top_right = aia171_test_map.wcs.world_to_pixel(tp_coord)
+
+    bottom_left_x, bottom_left_y = map(int, bottom_left)
+    top_right_x, top_right_y = map(int, top_right)
+
+    submap = aia171_test_map.submap([bottom_left_x, bottom_left_y]*u.pix,
+                                    top_right=[top_right_x, top_right_y]*u.pix
+                                    )
+
+    sliced_map = aia171_test_map[bottom_left_y : top_right_y + 1, bottom_left_x: top_right_x + 1]
+
+    assert_cubes_equal(submap, sliced_map)