Add test for asdf data duplication issue with fits (#105)

* Add test for asdf data duplication issue with fits

See asdf issue asdf-format/asdf#1232

This test is currently skipped as it will fail with the current
asdf version.

* bump asdf to 2.14.1 to fix hdu data duplication

* update changelog

CHANGES.rst

@@ -4,7 +4,7 @@
 Bug Fixes
 ---------
 
--
+- Increase asdf version to >=2.14.1 to fix hdu data duplication [#105]
 
 Changes to API
 --------------

setup.cfg

@@ -22,9 +22,8 @@ setup_requires =
 install_requires =
     jsonschema>=3.0.2
     # The tests require code that is in asdf master
-    # but not yet released.  The package itself
-    # is compatible with asdf 2.7.
-    asdf>=2.7.1
+    # but not yet released.
+    asdf>=2.14.1
     psutil>=5.7.2
     numpy>=1.16
     astropy>=5.0.4

tests/test_fits.py

@@ -619,3 +619,23 @@ def test_ndarray_validation(tmp_path):
     with pytest.raises(ValidationError, match="Wrong number of dimensions: Expected 2, got 1"):
         with FitsModel(file_path, strict_validation=True, cast_fits_arrays=False, validate_arrays=True) as model:
             model.validate()
+
+
+def test_resave_duplication_bug(tmp_path):
+    """
+    An issue in asdf (https://github.com/asdf-format/asdf/issues/1232)
+    resulted in duplication of data when a model was read from and then
+    written to a fits file.
+    """
+    fn1 = tmp_path / "test1.fits"
+    fn2 = tmp_path / "test2.fits"
+
+    arr = np.zeros((1000, 100), dtype='f4')
+    m = FitsModel(arr)
+    m.save(fn1)
+
+    m2 = FitsModel.from_fits(fn1)
+    m2.save(fn2)
+
+    with fits.open(fn1) as ff1, fits.open(fn2) as ff2:
+        assert ff1['ASDF'].size == ff2['ASDF'].size