Fix "�� is not JSON serializable" on Python 3

.github/workflows/deploy.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-18.04
 
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
 
       - name: Set up Python 3.8
         uses: actions/setup-python@v1

.github/workflows/lint.yml

@@ -10,7 +10,7 @@ jobs:
         python-version: [3.8]
 
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
 
       - name: pip cache
         uses: actions/cache@v1

.github/workflows/test.yml

@@ -14,7 +14,7 @@ jobs:
           - {python-version: 2.7, os: windows-2019}
 
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
 
       - name: Ubuntu cache
         uses: actions/cache@v1

python/objToJSON.c

@@ -662,7 +662,13 @@ static void Object_beginTypeContext (JSOBJ _obj, JSONTypeContext *tc, JSONObject
   PyErr_Clear();
 
   objRepr = PyObject_Repr(obj);
+#if PY_MAJOR_VERSION >= 3
+  PyObject* str = PyUnicode_AsEncodedString(objRepr, "utf-8", "~E~");
+  PyErr_Format (PyExc_TypeError, "%s is not JSON serializable", PyString_AS_STRING(str));
+  Py_XDECREF(str);
+#else
   PyErr_Format (PyExc_TypeError, "%s is not JSON serializable", PyString_AS_STRING(objRepr));
+#endif
   Py_DECREF(objRepr);
 
 INVALID:

tests/test_ujson.py

@@ -606,6 +606,33 @@ def test_dumps(test_input, expected):
     assert ujson.dumps(test_input) == expected
 
 
+class SomeObject:
+    def __repr__(self):
+        return "Some Object"
+
+
+if sys.version_info.major == 2:
+    EMPTY_SET_ERROR = "set([]) is not JSON serializable"
+    FILLED_SET_ERROR = "set([1, 2, 3]) is not JSON serializable"
+else:
+    EMPTY_SET_ERROR = "set() is not JSON serializable"
+    FILLED_SET_ERROR = "{1, 2, 3} is not JSON serializable"
+
+
+@pytest.mark.parametrize(
+    "test_input, expected_exception, expected_message",
+    [
+        (set(), TypeError, EMPTY_SET_ERROR),
+        ({1, 2, 3}, TypeError, FILLED_SET_ERROR),
+        (SomeObject(), TypeError, "Some Object is not JSON serializable"),
+    ],
+)
+def test_dumps_raises(test_input, expected_exception, expected_message):
+    with pytest.raises(expected_exception) as e:
+        ujson.dumps(test_input)
+    assert str(e.value) == expected_message
+
+
 @pytest.mark.parametrize(
     "test_input",
     [