Explicitly check for "EN" at end of .ori files

cosipy/spacecraftfile/spacecraft_file.py

@@ -402,10 +402,25 @@ def _open_ori(cls, file, tstart:Time = None, tstop:Time = None) -> "SpacecraftHi
         # Type OrientationsGalactic
         # ...
         # EN
-        # Using [:-1] instead of skipfooter=1 because otherwise it's
-        # slow and you get ParserWarning: Falling back to the 'python'
-        # engine because the 'c' engine does not support skipfooter;
-        # you can avoid this warning by specifying engine='python'.
+
+        # Check that the EN line is present (and throw an error if
+        # not), lest we accidentally drop the last line of orientation
+        # data!
+        with open(file, "rb") as ori_file:
+            ori_file.seek(-4, 2)
+            s = ori_file.read(4)
+
+            # allow for possibility of missing EOL at end of file
+            if s[-1] == ord('\n'):
+                s = s[:-1]
+
+            if s != b'\nEN':
+                raise ValueError(".ori file must end with final line 'EN'!")
+
+        # now read the full file, skipping the first and last line.
+        # Use [:-1] instead of skipfooter=1; the latter causes a
+        # fallback to the slow Python CSV reading engine instead of
+        # faster C engine.
 
         df = pd.read_csv(file, sep=r"\s+", skiprows=1,
                          usecols=tuple(range(1,10)),
@@ -1141,7 +1156,7 @@ def get_exposure(self, source:Union[SkyCoord, np.ndarray],
             # do not interpolate
             pixels = base.ang2pix(theta=theta,
                                   phi=phi,
-                                  lonlat=lonlat)
+                                  lonlat=False)
             weighted_duration = duration
 
         unique_pixels, unique_weights = \

tests/spacecraftfile/test_spacecraftfile.py

@@ -5,6 +5,8 @@
 from astropy.io import fits
 from astropy.time import Time
 
+from mhealpy import HealpixBase
+
 from cosipy import test_data
 from cosipy import SpacecraftHistory
 
@@ -185,6 +187,27 @@ def test_interp_location():
                        ori.location[1].cartesian.xyz.to_value(u.km))
 
 
+def test_get_exposure():
+    ori_path = test_data.path / "20280301_first_10sec.fits"
+    ori = SpacecraftHistory.open(ori_path)
+
+    target_coord = SkyCoord(l=184.5551, b = -05.7877,
+                            unit = u.deg, frame = "galactic")
+
+    b = HealpixBase(nside=1)
+    pix, weights = ori.get_exposure(target_coord, b,
+                                    interp = True, earth_occ = False)
+
+    assert np.array_equal(pix, [0, 1, 2, 3])
+    assert np.allclose(weights,
+                       [1.89505713, 7.61558445, 0.24467921, 0.24467921] * u.s)
+
+    pix, weights = ori.get_exposure(target_coord, b,
+                                    interp = False, earth_occ = False)
+
+    assert np.array_equal(pix, [1])
+    assert np.allclose(weights, [10.] * u.s)
+
 def test_get_dwell_map():
 
     ori_path = test_data.path / "20280301_first_10sec.fits"