Add unittests to document serialisation of tuples (#246)

Also, fix formatting of error message in case of tuple.
See https://github.com/msgpack/msgpack-python/issues/245

msgpack/fallback.py

@@ -795,7 +795,7 @@ class Packer(object):
                 obj = self._default(obj)
                 default_used = 1
                 continue
-            raise TypeError("Cannot serialize %r" % obj)
+            raise TypeError("Cannot serialize %r" % (obj, ))
 
     def pack(self, obj):
         self._pack(obj)

test/test_stricttype.py

@@ -1,7 +1,7 @@
 # coding: utf-8
 
 from collections import namedtuple
-from msgpack import packb, unpackb
+from msgpack import packb, unpackb, ExtType
 
 
 def test_namedtuple():
@@ -13,3 +13,50 @@ def test_namedtuple():
     packed = packb(T(1, 42), strict_types=True, use_bin_type=True, default=default)
     unpacked = unpackb(packed, encoding='utf-8')
     assert unpacked == {'foo': 1, 'bar': 42}
+
+
+def test_tuple():
+    t = ('one', 2, b'three', (4, ))
+
+    def default(o):
+        if isinstance(o, tuple):
+            return {
+                '__type__': 'tuple',
+                'value': list(o),
+                }
+        raise TypeError('Unsupported type %s' % (type(o),))
+
+    def convert(o):
+        if o.get('__type__') == 'tuple':
+            return tuple(o['value'])
+        return o
+
+    data = packb(t, strict_types=True, use_bin_type=True, default=default)
+    expected = unpackb(data, encoding='utf-8', object_hook=convert)
+
+    assert expected == t
+
+
+def test_tuple_ext():
+    t = ('one', 2, b'three', (4, ))
+
+    MSGPACK_EXT_TYPE_TUPLE = 0
+
+    def default(o):
+        if isinstance(o, tuple):
+            # Convert to list and pack
+            payload = packb(
+                list(o), strict_types=True, use_bin_type=True, default=default)
+            return ExtType(MSGPACK_EXT_TYPE_TUPLE, payload)
+        raise TypeError(repr(o))
+
+    def convert(code, payload):
+        if code == MSGPACK_EXT_TYPE_TUPLE:
+            # Unpack and convert to tuple
+            return tuple(unpackb(payload, encoding='utf-8', ext_hook=convert))
+        raise ValueError('Unknown Ext code {}'.format(code))
+
+    data = packb(t, strict_types=True, use_bin_type=True, default=default)
+    expected = unpackb(data, encoding='utf-8', ext_hook=convert)
+
+    assert expected == t