py/objdict: Support ujson.dump() of OrderedDict objects.

Following CPython, OrderedDict are dumped with the syntax of dict.

1 files changed, 12 insertions, 0 deletions

diff --git a/tests/extmod/ujson_dumps_ordereddict.py b/tests/extmod/ujson_dumps_ordereddict.py
new file mode 100644
index 000000000..c6f4a8fcb
--- /dev/null
+++ b/tests/extmod/ujson_dumps_ordereddict.py
@@ -0,0 +1,12 @@
+try:
+    import ujson as json
+    from ucollections import OrderedDict
+except ImportError:
+    try:
+        import json
+        from collections import OrderedDict
+    except ImportError:
+        print("SKIP")
+        raise SystemExit
+
+print(json.dumps(OrderedDict(((1, 2), (3, 4)))))