Fixed #30677 -- Improved error message for urlencode() and Client when None is passed as data.

django/test/client.py

@@ -193,8 +193,8 @@ def encode_multipart(boundary, data):
     for (key, value) in data.items():
         if value is None:
             raise TypeError(
-                'Cannot encode None as POST data. Did you mean to pass an '
-                'empty string or omit the value?'
+                "Cannot encode None for key '%s' as POST data. Did you mean "
+                "to pass an empty string or omit the value?" % key
             )
         elif is_file(value):
             lines.extend(encode_file(boundary, key, value))

django/utils/http.py

@@ -113,8 +113,8 @@ def urlencode(query, doseq=False):
     for key, value in query:
         if value is None:
             raise TypeError(
-                'Cannot encode None in a query string. Did you mean to pass '
-                'an empty string or omit the value?'
+                "Cannot encode None for key '%s' in a query string. Did you "
+                "mean to pass an empty string or omit the value?" % key
             )
         elif not doseq or isinstance(value, (str, bytes)):
             query_val = value
@@ -130,8 +130,9 @@ def urlencode(query, doseq=False):
                 for item in itr:
                     if item is None:
                         raise TypeError(
-                            'Cannot encode None in a query string. Did you '
-                            'mean to pass an empty string or omit the value?'
+                            "Cannot encode None for key '%s' in a query "
+                            "string. Did you mean to pass an empty string or "
+                            "omit the value?" % key
                         )
                     elif not isinstance(item, bytes):
                         item = str(item)

tests/test_client/tests.py

@@ -61,8 +61,8 @@ class ClientTest(TestCase):
 
     def test_get_data_none(self):
         msg = (
-            'Cannot encode None in a query string. Did you mean to pass an '
-            'empty string or omit the value?'
+            "Cannot encode None for key 'value' in a query string. Did you "
+            "mean to pass an empty string or omit the value?"
         )
         with self.assertRaisesMessage(TypeError, msg):
             self.client.get('/get_view/', {'value': None})
@@ -102,8 +102,8 @@ class ClientTest(TestCase):
 
     def test_post_data_none(self):
         msg = (
-            'Cannot encode None as POST data. Did you mean to pass an empty '
-            'string or omit the value?'
+            "Cannot encode None for key 'value' as POST data. Did you mean "
+            "to pass an empty string or omit the value?"
         )
         with self.assertRaisesMessage(TypeError, msg):
             self.client.post('/post_view/', {'value': None})

tests/utils_tests/test_http.py

@@ -14,8 +14,8 @@ from django.utils.http import (
 
 class URLEncodeTests(SimpleTestCase):
     cannot_encode_none_msg = (
-        'Cannot encode None in a query string. Did you mean to pass an '
-        'empty string or omit the value?'
+        "Cannot encode None for key 'a' in a query string. Did you mean to "
+        "pass an empty string or omit the value?"
     )
 
     def test_tuples(self):