TST: Stop using roundtrip_object

specutils/io/asdf/tags/tests/test_spectra.py

@@ -1,7 +1,6 @@
 import asdf
 import numpy as np
 import pytest
-from asdf.testing.helpers import roundtrip_object
 from astropy import units as u
 from astropy.coordinates import FK5
 from astropy.nddata import StdDevUncertainty
@@ -19,35 +18,52 @@ def create_spectrum1d(xmin, xmax, uncertainty=None):
 
 
 @pytest.mark.parametrize('uncertainty', [False, True])
-def test_asdf_spectrum1d(uncertainty):
+def test_asdf_spectrum1d(tmp_path, uncertainty):
+    file_path = tmp_path / "test.asdf"
     spectrum = create_spectrum1d(5100, 5300, uncertainty=uncertainty)
-    assert_spectrum1d_equal(spectrum, roundtrip_object(spectrum))
+    with asdf.AsdfFile() as af:
+        af["spectrum"] = spectrum
+        af.write_to(file_path)
+
+    with asdf.open(file_path) as af:
+        assert_spectrum1d_equal(af["spectrum"], spectrum)
 
 
 @pytest.mark.xfail
-def test_asdf_spectralaxis():
+def test_asdf_spectralaxis(tmp_path):
+    file_path = tmp_path / "test.asdf"
     wavelengths  = np.arange(5100, 5300) * u.AA
     spectral_axis = SpectralAxis(wavelengths, bin_specification="edges")
     # There is no implemented asdf type for SpectralAxis and no defined
     # equality comparison (assert_spectralaxis_equal)
     # per the comment https://github.com/astropy/specutils/pull/645#issuecomment-614271632 ;
     # the issue is that SpectralAxis roundtrips as SpectralCoord
     # so the types differ.
-    rt = roundtrip_object(spectral_axis)
-    assert type(rt) == type(spectral_axis)
+    with asdf.AsdfFile() as af:
+        af["spectral_axis"] = spectral_axis
+        af.write_to(file_path)
+
+    with asdf.open(file_path) as af:
+        assert type(af["spectral_axis"]) == type(spectral_axis)
 
 
-def test_asdf_spectrumlist():
+def test_asdf_spectrumlist(tmp_path):
+    file_path = tmp_path / "test.asdf"
     spectra = SpectrumList([
         create_spectrum1d(5100, 5300),
         create_spectrum1d(5000, 5500),
         create_spectrum1d(0, 100),
         create_spectrum1d(1, 5)
     ])
-    assert_spectrumlist_equal(spectra, roundtrip_object(spectra))
+    with asdf.AsdfFile() as af:
+        af["spectrum_list"] = spectra
+        af.write_to(file_path)
+
+    with asdf.open(file_path) as af:
+        assert_spectrumlist_equal(af["spectrum_list"], spectra)
 
 
 def test_asdf_url_mapper():
     """Make sure specutils ASDF extension url_mapping does not interfere with astropy schemas."""
-    af = asdf.AsdfFile()
-    af.tree = {'frame': FK5()}
+    with asdf.AsdfFile() as af:
+        af.tree = {'frame': FK5()}