fix numerous mistakes

Author: andrewsg

tests/unit/test_fileio.py

@@ -416,6 +416,8 @@ def test_close_errors(self):
         writer.close()
         # Close a second time to verify it successfully does nothing.
         writer.close()
+
+        self.assertTrue(writer.closed)
         # Try to write to closed file.
         with self.assertRaises(ValueError):
             writer.write(TEST_BINARY_DATA)
@@ -768,7 +770,7 @@ def test_seek(self):
     def test_close(self):
         buff = self._make_sliding_buffer()
         buff.close()
-        self.assertTrue(buff.closed())
+        self.assertTrue(buff.closed)
         with self.assertRaises(ValueError):
             buff.read()
 
@@ -915,7 +917,7 @@ def test_close(self):
         reader = self._make_blob_reader(blob)
 
         reader.close()
-        self.assertRaises(self.closed)
+        self.assertTrue(reader.closed)
 
         with self.assertRaises(ValueError):
             reader.read()