.

specreduce/tests/test_tracing.py

@@ -150,7 +150,7 @@ def test_fit_trace():
     with pytest.raises(ValueError, match=r'image is fully masked'):
         FitTrace(img_all_nans)
 
-    # test that warning is raised when many bins are masked
+    # test that warning is raised when several bins are masked
     mask = np.zeros(img.shape)
     mask[:, 100] = 1
     mask[:, 20] = 1
@@ -159,3 +159,12 @@ def test_fit_trace():
     msg = "All pixels in bins 20, 30, 100 are masked. Falling to trace value from all-bin fit."
     with pytest.warns(UserWarning, match=msg):
         FitTrace(nddat)
+
+    # and when many bins are masked
+    mask = np.zeros(img.shape)
+    mask[:, 0:21] = 1
+    nddat = NDData(data=img, mask=mask, unit=u.DN)
+    msg = 'All pixels in bins 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ..., 20 are masked. Falling to trace value from all-bin fit.'
+    with pytest.warns(UserWarning, match=msg):
+        FitTrace(nddat)
+

specreduce/tracing.py

@@ -352,7 +352,7 @@ def __post_init__(self):
             # if there are a ton of bins, we don't want to print them all out
             print(warn_bins)
             if len(warn_bins) > 20:
-                warn_bins = warn_bins[0: 10] + ['...'] + warn_bins[10: 19]
+                warn_bins = warn_bins[0: 10] + ['...'] + [warn_bins[-1]]
             warnings.warn(f"All pixels in bin{plural} {', '.join([str(x) for x in warn_bins])}"
                           " are masked. Falling to trace value from all-bin fit.")