Test Hdf5StubImagePlugin for correctness

Tests/test_file_hdf5stub.py

@@ -1,16 +1,50 @@
 from helper import unittest, PillowTestCase
 
-from PIL import Hdf5StubImagePlugin
+from PIL import Hdf5StubImagePlugin, Image
+
+TEST_FILE = "Tests/images/hdf5.h5"
 
 
 class TestFileHdf5Stub(PillowTestCase):
 
-    def test_invalid_file(self):
+    def test_open(self):
-        test_file = "Tests/images/flower.jpg"
+        # Act
+        im = Image.open(TEST_FILE)
 
+        # Assert
+        self.assertEqual(im.format, "HDF5")
+
+        # Dummy data from the stub
+        self.assertEqual(im.mode, "F")
+        self.assertEqual(im.size, (1, 1))
+
+    def test_invalid_file(self):
+        # Arrange
+        invalid_file = "Tests/images/flower.jpg"
+
+        # Act / Assert
         self.assertRaises(SyntaxError,
                           lambda:
-                          Hdf5StubImagePlugin.HDF5StubImageFile(test_file))
+                          Hdf5StubImagePlugin.HDF5StubImageFile(invalid_file))
+
+    def test_load(self):
+        # Arrange
+        im = Image.open(TEST_FILE)
+
+        # Act / Assert: stub cannot load without an implemented handler
+        self.assertRaises(IOError, lambda: im.load())
+
+    def test_save(self):
+        # Arrange
+        im = Image.open(TEST_FILE)
+        dummy_fp = None
+        dummy_filename = "dummy.filename"
+
+        # Act / Assert: stub cannot save without an implemented handler
+        self.assertRaises(IOError, lambda: im.save(dummy_filename))
+        self.assertRaises(
+            IOError,
+            lambda: Hdf5StubImagePlugin._save(im, dummy_fp, dummy_filename))
 
 
 if __name__ == '__main__':