Add datetime.date support to JSONEncoder

CHANGES

@@ -61,6 +61,7 @@ Version 1.0
 - The automatically provided ``OPTIONS`` method is now correctly disabled if
   the user registered an overriding rule with the lowercase-version
   ``options`` (issue ``#1288``).
+- flask.json.jsonify now supports the datetime.date type
 
 Version 0.10.2
 --------------

flask/json.py

@@ -10,7 +10,7 @@
 """
 import io
 import uuid
-from datetime import datetime
+from datetime import date
 from .globals import current_app, request
 from ._compat import text_type, PY2
 
@@ -74,8 +74,8 @@ class JSONEncoder(_json.JSONEncoder):
                     return list(iterable)
                 return JSONEncoder.default(self, o)
         """
-        if isinstance(o, datetime):
+        if isinstance(o, date):
-            return http_date(o)
+            return http_date(o.timetuple())
         if isinstance(o, uuid.UUID):
             return str(o)
         if hasattr(o, '__html__'):

tests/test_helpers.py

@@ -12,9 +12,11 @@
 import pytest
 
 import os
+import datetime
 import flask
 from logging import StreamHandler
 from werkzeug.http import parse_cache_control_header, parse_options_header
+from werkzeug.http import http_date
 from flask._compat import StringIO, text_type
 
 
@@ -29,6 +31,24 @@ def has_encoding(name):
 
 class TestJSON(object):
 
+    def test_jsonify_date_types(self):
+        """Test jsonify with datetime.date and datetime.datetime types."""
+
+        test_dates = (
+            datetime.datetime(1973, 3, 11, 6, 30, 45),
+            datetime.date(1975, 1, 5)
+        )
+
+        app = flask.Flask(__name__)
+        c = app.test_client()
+
+        for i, d in enumerate(test_dates):
+            url = '/datetest{0}'.format(i)
+            app.add_url_rule(url, str(i), lambda val=d: flask.jsonify(x=val))
+            rv = c.get(url)
+            assert rv.mimetype == 'application/json'
+            assert flask.json.loads(rv.data)['x'] == http_date(d.timetuple())
+
     def test_json_bad_requests(self):
         app = flask.Flask(__name__)
         @app.route('/json', methods=['POST'])