ENH: Test serialize via an API test mixin

Author: effigies

nibabel/tests/test_filebasedimages.py

@@ -5,9 +5,9 @@
 
 import numpy as np
 
-from nibabel.filebasedimages import FileBasedHeader, FileBasedImage
+from ..filebasedimages import FileBasedHeader, FileBasedImage
 
-from nibabel.tests.test_image_api import GenericImageAPI
+from .test_image_api import GenericImageAPI, SerializeMixin
 
 from nose.tools import (assert_true, assert_false, assert_equal,
                         assert_not_equal)
@@ -50,7 +50,8 @@ def set_data_dtype(self, dtype):
         self.arr = self.arr.astype(dtype)
 
 
-class TestFBImageAPI(GenericImageAPI):
+class TestFBImageAPI(GenericImageAPI,
+                     SerializeMixin):
     """ Validation for FileBasedImage instances
     """
     # A callable returning an image from ``image_maker(data, header)``

nibabel/tests/test_image_api.py

@@ -493,6 +493,19 @@ def validate_affine_deprecated(self, imaker, params):
             assert_true(aff is img.get_affine())
 
 
+class SerializeMixin(object):
+
+    def validate_serialize(self, imaker, params):
+        img = imaker()
+        serialized = img.serialize()
+        with InTemporaryDirectory():
+            fname = 'img' + self.standard_extension
+            img.to_filename(fname)
+            with open(fname, 'rb') as fobj:
+                file_contents = fobj.read()
+        assert serialized == file_contents
+
+
 class LoadImageAPI(GenericImageAPI,
                    DataInterfaceMixin,
                    AffineMixin,
@@ -613,7 +626,7 @@ class TestNifti1PairAPI(TestSpm99AnalyzeAPI):
     can_save = True
 
 
-class TestNifti1API(TestNifti1PairAPI):
+class TestNifti1API(TestNifti1PairAPI, SerializeMixin):
     klass = image_maker = Nifti1Image
     standard_extension = '.nii'
 
@@ -660,7 +673,7 @@ def loader(self, fname):
 #    standard_extension = '.v'
 
 
-class TestMGHAPI(ImageHeaderAPI):
+class TestMGHAPI(ImageHeaderAPI, SerializeMixin):
     klass = image_maker = MGHImage
     example_shapes = ((2, 3, 4), (2, 3, 4, 5))  # MGH can only do >= 3D
     has_scaling = True