From 42bc4c92920a4073ffb02ec503ea3889d5c6768d Mon Sep 17 00:00:00 2001
From: Dave Shawley <daves@aweber.com>
Date: Fri, 5 Nov 2021 07:20:10 -0400
Subject: [PATCH] Add support for encoding namedtuples as tuples

---
 docs/history.rst                          |  1 +
 sprockets/mixins/mediatype/transcoders.py |  3 +++
 tests.py                                  | 21 +++++++++++++++++++++
 3 files changed, 25 insertions(+)

diff --git a/docs/history.rst b/docs/history.rst
index 9e28945..6495ae7 100644
--- a/docs/history.rst
+++ b/docs/history.rst
@@ -9,6 +9,7 @@ Version History
 - Add support for encoding :class:`ipaddress.IPv4Address` and :class:`ipaddress.IPv6Address`
 - Add support for encoding :class:`pathlib.Path`
 - Add support for encoding :class:`array.array`
+- Add support for encoding :class:`collections.namedtuple` instances as tuples
 - Add type annotations (see :ref:`type-info`)
 - Return a "406 Not Acceptable" if the :http:header:`Accept` header values cannot be matched
   and there is no default content type configured
diff --git a/sprockets/mixins/mediatype/transcoders.py b/sprockets/mixins/mediatype/transcoders.py
index 0f8f0a7..e7d0717 100644
--- a/sprockets/mixins/mediatype/transcoders.py
+++ b/sprockets/mixins/mediatype/transcoders.py
@@ -506,6 +506,9 @@ class FormUrlEncodedTranscoder:
             return ''.join(char_map[c] for c in datum)
         elif isinstance(datum, type_info.SupportsIsoFormat):
             str_repr = datum.isoformat()
+        # the following check is for namedtuples
+        elif isinstance(datum, tuple) and datum.__class__ is not tuple:
+            str_repr = str(tuple(datum))
         else:
             str_repr = str(datum)
 
diff --git a/tests.py b/tests.py
index c467de3..086aebc 100644
--- a/tests.py
+++ b/tests.py
@@ -1,5 +1,6 @@
 import array
 import base64
+import collections
 import dataclasses
 import datetime
 import decimal
@@ -403,6 +404,13 @@ class JSONTranscoderTests(unittest.TestCase):
         self.assertEqual(dumped,
                          '{"array":[%s]}' % (','.join(str(x) for x in a), ))
 
+    def test_that_namedtuples_are_handled_as_tuples(self):
+        Point = collections.namedtuple('Point', ['x', 'y'])
+        datum = Point(3, 4)
+        dumped = self.transcoder.dumps({'point': datum})
+        expected = json.dumps({'point': [x for x in datum]})
+        self.assertDictEqual(json.loads(expected), json.loads(dumped))
+
 
 class ContentSettingsTests(unittest.TestCase):
     def test_that_handler_listed_in_available_content_types(self):
@@ -667,6 +675,12 @@ class MsgPackTranscoderTests(unittest.TestCase):
             expected += pack_string(ch)
         self.assertEqual(expected, self.transcoder.packb(a))
 
+    def test_that_namedtuples_are_handled_as_tuples(self):
+        Point = collections.namedtuple('Point', ['x', 'y'])
+        datum = Point(3, 4)
+        expected = struct.pack('>BBB', 0x90 | 2, 3, 4)
+        self.assertEqual(expected, self.transcoder.packb(datum))
+
 
 class FormUrlEncodingTranscoderTests(unittest.TestCase):
     transcoder: type_info.Transcoder
@@ -851,3 +865,10 @@ class FormUrlEncodingTranscoderTests(unittest.TestCase):
         _, expected = self.transcoder.to_bytes({'array': a.tolist()})
         _, result = self.transcoder.to_bytes({'array': a})
         self.assertEqual(expected, result)
+
+    def test_that_namedtuples_are_handled_as_tuples(self):
+        Point = collections.namedtuple('Point', ['x', 'y'])
+        datum = Point(3, 4)
+        _, expected = self.transcoder.to_bytes({'point': (3, 4)})
+        _, result = self.transcoder.to_bytes({'point': datum})
+        self.assertEqual(expected, result)