TEST: Generate file when no examples available

Author: effigies

nibabel/filebasedimages.py

@@ -567,7 +567,7 @@ def from_bytes(klass, bytestring):
         bstring : bytes
             Byte string containing the on-disk representation of an image
         """
-        bio = io.BytesIO(bstring)
+        bio = io.BytesIO(bytestring)
         file_map = klass.make_file_map({'image': bio, 'header': bio})
         return klass.from_file_map(file_map)
 

nibabel/tests/test_filebasedimages.py

@@ -5,7 +5,7 @@
 
 import numpy as np
 
-from ..filebasedimages import FileBasedHeader, FileBasedImage
+from ..filebasedimages import FileBasedHeader, FileBasedImage, SerializableImage
 
 from .test_image_api import GenericImageAPI, SerializeMixin
 
@@ -50,8 +50,11 @@ def set_data_dtype(self, dtype):
         self.arr = self.arr.astype(dtype)
 
 
-class TestFBImageAPI(GenericImageAPI,
-                     SerializeMixin):
+class SerializableNumpyImage(FBNumpyImage, SerializableImage):
+    pass
+
+
+class TestFBImageAPI(GenericImageAPI):
     """ Validation for FileBasedImage instances
     """
     # A callable returning an image from ``image_maker(data, header)``
@@ -81,6 +84,10 @@ def obj_params(self):
             yield func, params
 
 
+class TestSerializableImageAPI(TestFBImageAPI, SerializeMixin):
+    image_maker = SerializableNumpyImage
+
+
 def test_filebased_header():
     # Test stuff about the default FileBasedHeader
 

nibabel/tests/test_image_api.py

@@ -505,24 +505,36 @@ def validate_to_bytes(self, imaker, params):
         assert serialized == file_contents
 
     def validate_from_bytes(self, imaker, params):
-        for img_params in self.example_images:
-            img_a = self.klass.from_filename(img_params['fname'])
-            with open(img_params['fname'], 'rb') as fobj:
-                img_b = self.klass.from_bytes(fobj.read())
+        img = imaker()
+        with InTemporaryDirectory():
+            fname = 'img' + self.standard_extension
+            img.to_filename(fname)
 
-            assert img_a.header == img_b.header
-            assert np.array_equal(img_a.get_data(), img_b.get_data())
+            all_images = list(getattr(self, 'example_images', [])) + [{'fname': fname}]
+            for img_params in all_images:
+                img_a = self.klass.from_filename(img_params['fname'])
+                with open(img_params['fname'], 'rb') as fobj:
+                    img_b = self.klass.from_bytes(fobj.read())
 
-    def validate_round_trip(self, imaker, params):
-        for img_params in self.example_images:
-            img_a = self.klass.from_filename(img_params['fname'])
-            bytes_a = img_a.to_bytes()
+                assert img_a.header == img_b.header
+                assert np.array_equal(img_a.get_data(), img_b.get_data())
+
+    def validate_to_from_bytes(self, imaker, params):
+        img = imaker()
+        with InTemporaryDirectory():
+            fname = 'img' + self.standard_extension
+            img.to_filename(fname)
+
+            all_images = list(getattr(self, 'example_images', [])) + [{'fname': fname}]
+            for img_params in all_images:
+                img_a = self.klass.from_filename(img_params['fname'])
+                bytes_a = img_a.to_bytes()
 
-            img_b = self.klass.from_bytes(bytes_a)
+                img_b = self.klass.from_bytes(bytes_a)
 
-            assert img_b.to_bytes() == bytes_a
-            assert img_a.header == img_b.header
-            assert np.array_equal(img_a.get_data(), img_b.get_data())
+                assert img_b.to_bytes() == bytes_a
+                assert img_a.header == img_b.header
+                assert np.array_equal(img_a.get_data(), img_b.get_data())
 
 
 class LoadImageAPI(GenericImageAPI,