diff --git a/tests/cpython/__init__.py b/tests/cpython/__init__.py
new file mode 100644
index 0000000..d1d3e1e
--- /dev/null
+++ b/tests/cpython/__init__.py
@@ -0,0 +1,77 @@
+import os
+import json
+import doctest
+import unittest
+
+from test import support
+
+# import json with and without accelerations
+cjson = support.import_fresh_module('json', fresh=['_json'])
+pyjson = support.import_fresh_module('json', blocked=['_json'])
+hyperjson = support.import_fresh_module('hyperjson')
+# JSONDecodeError is cached inside the _json module
+cjson.JSONDecodeError = cjson.decoder.JSONDecodeError = json.JSONDecodeError
+
+# create two base classes that will be used by the other tests
+class PyTest(unittest.TestCase):
+    json = pyjson
+    loads = staticmethod(pyjson.loads)
+    dumps = staticmethod(pyjson.dumps)
+    JSONDecodeError = staticmethod(pyjson.JSONDecodeError)
+
+@unittest.skipUnless(cjson, 'requires _json')
+class CTest(unittest.TestCase):
+    if cjson is not None:
+        json = cjson
+        loads = staticmethod(cjson.loads)
+        dumps = staticmethod(cjson.dumps)
+        JSONDecodeError = staticmethod(cjson.JSONDecodeError)
+
+@unittest.skipUnless(hyperjson, 'requires hyperjson')
+class RustTest(unittest.TestCase):
+    if hyperjson is not None:
+        json = hyperjson
+        loads = staticmethod(hyperjson.loads)
+        dumps = staticmethod(hyperjson.dumps)
+        # FIXME: hyperjson does not have this
+        JSONDecodeError = staticmethod(pyjson.JSONDecodeError)
+        # JSONDecodeError = staticmethod(hyperjson.JSONDecodeError)
+
+# test PyTest and CTest checking if the functions come from the right module
+class TestPyTest(PyTest):
+    def test_pyjson(self):
+        self.assertEqual(self.json.scanner.make_scanner.__module__,
+                         'json.scanner')
+        self.assertEqual(self.json.decoder.scanstring.__module__,
+                         'json.decoder')
+        self.assertEqual(self.json.encoder.encode_basestring_ascii.__module__,
+                         'json.encoder')
+
+class TestCTest(CTest):
+    def test_cjson(self):
+        self.assertEqual(self.json.scanner.make_scanner.__module__, '_json')
+        self.assertEqual(self.json.decoder.scanstring.__module__, '_json')
+        self.assertEqual(self.json.encoder.c_make_encoder.__module__, '_json')
+        self.assertEqual(self.json.encoder.encode_basestring_ascii.__module__,
+                         '_json')
+
+class TestRustTest(RustTest):
+    def test_hyperjson(self):
+        # FIXME: hyperjson does not have any of this
+        pass
+        # self.assertEqual(self.json.scanner.make_scanner.__module__, 'hyperjson')
+        # self.assertEqual(self.json.decoder.scanstring.__module__, 'hyperjson')
+        # self.assertEqual(self.json.encoder.c_make_encoder.__module__, 'hyperjson')
+        # self.assertEqual(self.json.encoder.encode_basestring_ascii.__module__,
+        #                  'hyperjson')
+
+
+def load_tests(loader, _, pattern):
+    suite = unittest.TestSuite()
+    for mod in (json, json.encoder, json.decoder):
+        suite.addTest(doctest.DocTestSuite(mod))
+    suite.addTest(TestPyTest('test_pyjson'))
+    suite.addTest(TestCTest('test_cjson'))
+
+    pkg_dir = os.path.dirname(__file__)
+    return support.load_package_tests(pkg_dir, loader, suite, pattern)
diff --git a/tests/cpython/__main__.py b/tests/cpython/__main__.py
new file mode 100644
index 0000000..7264b79
--- /dev/null
+++ b/tests/cpython/__main__.py
@@ -0,0 +1,4 @@
+import unittest
+from cpython import load_tests
+
+unittest.main()
diff --git a/tests/cpython/test_decode.py b/tests/cpython/test_decode.py
new file mode 100644
index 0000000..281a43f
--- /dev/null
+++ b/tests/cpython/test_decode.py
@@ -0,0 +1,98 @@
+import decimal
+from io import StringIO, BytesIO
+from collections import OrderedDict
+from cpython import PyTest, CTest, RustTest
+
+
+class _TestDecode:
+    def test_decimal(self):
+        rval = self.loads('1.1', parse_float=decimal.Decimal)
+        self.assertTrue(isinstance(rval, decimal.Decimal))
+        self.assertEqual(rval, decimal.Decimal('1.1'))
+
+    def test_float(self):
+        rval = self.loads('1', parse_int=float)
+        self.assertTrue(isinstance(rval, float))
+        self.assertEqual(rval, 1.0)
+
+    def test_empty_objects(self):
+        self.assertEqual(self.loads('{}'), {})
+        self.assertEqual(self.loads('[]'), [])
+        self.assertEqual(self.loads('""'), "")
+
+    def test_object_pairs_hook(self):
+        s = '{"xkd":1, "kcw":2, "art":3, "hxm":4, "qrt":5, "pad":6, "hoy":7}'
+        p = [("xkd", 1), ("kcw", 2), ("art", 3), ("hxm", 4),
+             ("qrt", 5), ("pad", 6), ("hoy", 7)]
+        self.assertEqual(self.loads(s), eval(s))
+        self.assertEqual(self.loads(s, object_pairs_hook=lambda x: x), p)
+        self.assertEqual(self.json.load(StringIO(s),
+                                        object_pairs_hook=lambda x: x), p)
+        od = self.loads(s, object_pairs_hook=OrderedDict)
+        self.assertEqual(od, OrderedDict(p))
+        self.assertEqual(type(od), OrderedDict)
+        # the object_pairs_hook takes priority over the object_hook
+        self.assertEqual(self.loads(s, object_pairs_hook=OrderedDict,
+                                    object_hook=lambda x: None),
+                         OrderedDict(p))
+        # check that empty object literals work (see #17368)
+        self.assertEqual(self.loads('{}', object_pairs_hook=OrderedDict),
+                         OrderedDict())
+        self.assertEqual(self.loads('{"empty": {}}',
+                                    object_pairs_hook=OrderedDict),
+                         OrderedDict([('empty', OrderedDict())]))
+
+    def test_decoder_optimizations(self):
+        # Several optimizations were made that skip over calls to
+        # the whitespace regex, so this test is designed to try and
+        # exercise the uncommon cases. The array cases are already covered.
+        rval = self.loads('{   "key"    :    "value"    ,  "k":"v"    }')
+        self.assertEqual(rval, {"key":"value", "k":"v"})
+
+    def check_keys_reuse(self, source, loads):
+        rval = loads(source)
+        (a, b), (c, d) = sorted(rval[0]), sorted(rval[1])
+        self.assertIs(a, c)
+        self.assertIs(b, d)
+
+    def test_keys_reuse(self):
+        s = '[{"a_key": 1, "b_\xe9": 2}, {"a_key": 3, "b_\xe9": 4}]'
+        self.check_keys_reuse(s, self.loads)
+        self.check_keys_reuse(s, self.json.decoder.JSONDecoder().decode)
+
+    def test_extra_data(self):
+        s = '[1, 2, 3]5'
+        msg = 'Extra data'
+        self.assertRaisesRegex(self.JSONDecodeError, msg, self.loads, s)
+
+    def test_invalid_escape(self):
+        s = '["abc\\y"]'
+        msg = 'escape'
+        self.assertRaisesRegex(self.JSONDecodeError, msg, self.loads, s)
+
+    def test_invalid_input_type(self):
+        msg = 'the JSON object must be str'
+        for value in [1, 3.14, [], {}, None]:
+            self.assertRaisesRegex(TypeError, msg, self.loads, value)
+
+    def test_string_with_utf8_bom(self):
+        # see #18958
+        bom_json = "[1,2,3]".encode('utf-8-sig').decode('utf-8')
+        with self.assertRaises(self.JSONDecodeError) as cm:
+            self.loads(bom_json)
+        self.assertIn('BOM', str(cm.exception))
+        with self.assertRaises(self.JSONDecodeError) as cm:
+            self.json.load(StringIO(bom_json))
+        self.assertIn('BOM', str(cm.exception))
+        # make sure that the BOM is not detected in the middle of a string
+        bom_in_str = '"{}"'.format(''.encode('utf-8-sig').decode('utf-8'))
+        self.assertEqual(self.loads(bom_in_str), '\ufeff')
+        self.assertEqual(self.json.load(StringIO(bom_in_str)), '\ufeff')
+
+    def test_negative_index(self):
+        d = self.json.JSONDecoder()
+        self.assertRaises(ValueError, d.raw_decode, 'a'*42, -50000)
+
+# class TestPyDecode(_TestDecode, PyTest): pass
+# class TestCDecode(_TestDecode, CTest): pass
+class TestRustDecode(_TestDecode, RustTest): pass
diff --git a/tests/cpython/test_default.py b/tests/cpython/test_default.py
new file mode 100644
index 0000000..ebecc16
--- /dev/null
+++ b/tests/cpython/test_default.py
@@ -0,0 +1,13 @@
+from cpython import PyTest, CTest, RustTest
+
+
+class _TestDefault:
+    def test_default(self):
+        self.assertEqual(
+            self.dumps(type, default=repr),
+            self.dumps(repr(type)))
+
+
+# class TestPyDefault(_TestDefault, PyTest): pass
+# class TestCDefault(_TestDefault, CTest): pass
+class TestRustDefault(_TestDefault, RustTest): pass
diff --git a/tests/cpython/test_dump.py b/tests/cpython/test_dump.py
new file mode 100644
index 0000000..30afcce
--- /dev/null
+++ b/tests/cpython/test_dump.py
@@ -0,0 +1,70 @@
+from io import StringIO
+from cpython import PyTest, CTest, RustTest
+
+from test.support import bigmemtest, _1G
+
+class _TestDump:
+    def test_dump(self):
+        sio = StringIO()
+        self.json.dump({}, sio)
+        self.assertEqual(sio.getvalue(), '{}')
+
+    def test_dumps(self):
+        self.assertEqual(self.dumps({}), '{}')
+
+    def test_encode_truefalse(self):
+        self.assertEqual(self.dumps(
+                 {True: False, False: True}, sort_keys=True),
+                 '{"false": true, "true": false}')
+        self.assertEqual(self.dumps(
+                {2: 3.0, 4.0: 5, False: 1, 6: True}, sort_keys=True),
+                '{"false": 1, "2": 3.0, "4.0": 5, "6": true}')
+
+    # Issue 16228: Crash on encoding resized list
+    def test_encode_mutated(self):
+        a = [object()] * 10
+        def crasher(obj):
+            del a[-1]
+        self.assertEqual(self.dumps(a, default=crasher),
+                 '[null, null, null, null, null]')
+
+    # Issue 24094
+    def test_encode_evil_dict(self):
+        class D(dict):
+            def keys(self):
+                return L
+
+        class X:
+            def __hash__(self):
+                del L[0]
+                return 1337
+
+            def __lt__(self, o):
+                return 0
+
+        L = [X() for i in range(1122)]
+        d = D()
+        d[1337] = "true.dat"
+        self.assertEqual(self.dumps(d, sort_keys=True), '{"1337": "true.dat"}')
+
+
+# class TestPyDump(_TestDump, PyTest): pass
+
+# class TestCDump(_TestDump, CTest):
+
+#     # The size requirement here is hopefully over-estimated (actual
+#     # memory consumption depending on implementation details, and also
+#     # system memory management, since this may allocate a lot of
+#     # small objects).
+
+#     @bigmemtest(size=_1G, memuse=1)
+#     def test_large_list(self, size):
+#         N = int(30 * 1024 * 1024 * (size / _1G))
+#         l = [1] * N
+#         encoded = self.dumps(l)
+#         self.assertEqual(len(encoded), N * 3)
+#         self.assertEqual(encoded[:1], "[")
+#         self.assertEqual(encoded[-2:], "1]")
+#         self.assertEqual(encoded[1:-2], "1, " * (N - 1))
+
+class TestRustDump(_TestDump, RustTest): pass
diff --git a/tests/cpython/test_encode_basestring_ascii.py b/tests/cpython/test_encode_basestring_ascii.py
new file mode 100644
index 0000000..1c7f8d1
--- /dev/null
+++ b/tests/cpython/test_encode_basestring_ascii.py
@@ -0,0 +1,50 @@
+from collections import OrderedDict
+from cpython import PyTest, CTest, RustTest
+from test.support import bigaddrspacetest
+
+
+CASES = [
+    ('/\\"\ucafe\ubabe\uab98\ufcde\ubcda\uef4a\x08\x0c\n\r\t`1~!@#$%^&*()_+-=[]{}|;:\',./<>?', '"/\\\\\\"\\ucafe\\ubabe\\uab98\\ufcde\\ubcda\\uef4a\\b\\f\\n\\r\\t`1~!@#$%^&*()_+-=[]{}|;:\',./<>?"'),
+    ('\u0123\u4567\u89ab\ucdef\uabcd\uef4a', '"\\u0123\\u4567\\u89ab\\ucdef\\uabcd\\uef4a"'),
+    ('controls', '"controls"'),
+    ('\x08\x0c\n\r\t', '"\\b\\f\\n\\r\\t"'),
+    ('{"object with 1 member":["array with 1 element"]}', '"{\\"object with 1 member\\":[\\"array with 1 element\\"]}"'),
+    (' s p a c e d ', '" s p a c e d "'),
+    ('\U0001d120', '"\\ud834\\udd20"'),
+    ('\u03b1\u03a9', '"\\u03b1\\u03a9"'),
+    ("`1~!@#$%^&*()_+-={':[,]}|;.</>?", '"`1~!@#$%^&*()_+-={\':[,]}|;.</>?"'),
+    ('\x08\x0c\n\r\t', '"\\b\\f\\n\\r\\t"'),
+    ('\u0123\u4567\u89ab\ucdef\uabcd\uef4a', '"\\u0123\\u4567\\u89ab\\ucdef\\uabcd\\uef4a"'),
+]
+
+class _TestEncodeBasestringAscii:
+    def test_encode_basestring_ascii(self):
+        fname = self.json.encoder.encode_basestring_ascii.__name__
+        for input_string, expect in CASES:
+            result = self.json.encoder.encode_basestring_ascii(input_string)
+            self.assertEqual(result, expect,
+                '{0!r} != {1!r} for {2}({3!r})'.format(
+                    result, expect, fname, input_string))
+
+    def test_ordered_dict(self):
+        # See issue 6105
+        items = [('one', 1), ('two', 2), ('three', 3), ('four', 4), ('five', 5)]
+        s = self.dumps(OrderedDict(items))
+        self.assertEqual(s, '{"one": 1, "two": 2, "three": 3, "four": 4, "five": 5}')
+
+    def test_sorted_dict(self):
+        items = [('one', 1), ('two', 2), ('three', 3), ('four', 4), ('five', 5)]
+        s = self.dumps(dict(items), sort_keys=True)
+        self.assertEqual(s, '{"five": 5, "four": 4, "one": 1, "three": 3, "two": 2}')
+
+
+# class TestPyEncodeBasestringAscii(_TestEncodeBasestringAscii, PyTest): pass
+# class TestCEncodeBasestringAscii(_TestEncodeBasestringAscii, CTest):
+#     @bigaddrspacetest
+#     def test_overflow(self):
+#         size = (2**32)//6 + 1
+#         s = "\x00"*size
+#         with self.assertRaises(OverflowError):
+#             self.json.encoder.encode_basestring_ascii(s)
+
+class TestRustEncodeBasestringAscii(_TestEncodeBasestringAscii, RustTest): pass
diff --git a/tests/cpython/test_enum.py b/tests/cpython/test_enum.py
new file mode 100644
index 0000000..4959427
--- /dev/null
+++ b/tests/cpython/test_enum.py
@@ -0,0 +1,121 @@
+from enum import Enum, IntEnum
+from math import isnan
+from cpython import PyTest, CTest, RustTest
+
+SMALL = 1
+BIG = 1<<32
+HUGE = 1<<64
+REALLY_HUGE = 1<<96
+
+class BigNum(IntEnum):
+    small = SMALL
+    big = BIG
+    huge = HUGE
+    really_huge = REALLY_HUGE
+
+E = 2.718281
+PI = 3.141593
+TAU = 2 * PI
+
+class FloatNum(float, Enum):
+    e = E
+    pi = PI
+    tau = TAU
+
+INF = float('inf')
+NEG_INF = float('-inf')
+NAN = float('nan')
+
+class WierdNum(float, Enum):
+    inf = INF
+    neg_inf = NEG_INF
+    nan = NAN
+
+class _TestEnum:
+
+    def test_floats(self):
+        for enum in FloatNum:
+            self.assertEqual(self.dumps(enum), repr(enum.value))
+            self.assertEqual(float(self.dumps(enum)), enum)
+            self.assertEqual(self.loads(self.dumps(enum)), enum)
+
+    def test_weird_floats(self):
+        for enum, expected in zip(WierdNum, ('Infinity', '-Infinity', 'NaN')):
+            self.assertEqual(self.dumps(enum), expected)
+            if not isnan(enum):
+                self.assertEqual(float(self.dumps(enum)), enum)
+                self.assertEqual(self.loads(self.dumps(enum)), enum)
+            else:
+                self.assertTrue(isnan(float(self.dumps(enum))))
+                self.assertTrue(isnan(self.loads(self.dumps(enum))))
+
+    def test_ints(self):
+        for enum in BigNum:
+            self.assertEqual(self.dumps(enum), str(enum.value))
+            self.assertEqual(int(self.dumps(enum)), enum)
+            self.assertEqual(self.loads(self.dumps(enum)), enum)
+
+    def test_list(self):
+        self.assertEqual(self.dumps(list(BigNum)),
+                         str([SMALL, BIG, HUGE, REALLY_HUGE]))
+        self.assertEqual(self.loads(self.dumps(list(BigNum))),
+                         list(BigNum))
+        self.assertEqual(self.dumps(list(FloatNum)),
+                         str([E, PI, TAU]))
+        self.assertEqual(self.loads(self.dumps(list(FloatNum))),
+                         list(FloatNum))
+        self.assertEqual(self.dumps(list(WierdNum)),
+                        '[Infinity, -Infinity, NaN]')
+        self.assertEqual(self.loads(self.dumps(list(WierdNum)))[:2],
+                         list(WierdNum)[:2])
+        self.assertTrue(isnan(self.loads(self.dumps(list(WierdNum)))[2]))
+
+    def test_dict_keys(self):
+        s, b, h, r = BigNum
+        e, p, t = FloatNum
+        i, j, n = WierdNum
+        d = {
+            s:'tiny', b:'large', h:'larger', r:'largest',
+            e:"Euler's number", p:'pi', t:'tau',
+            i:'Infinity', j:'-Infinity', n:'NaN',
+            }
+        nd = self.loads(self.dumps(d))
+        self.assertEqual(nd[str(SMALL)], 'tiny')
+        self.assertEqual(nd[str(BIG)], 'large')
+        self.assertEqual(nd[str(HUGE)], 'larger')
+        self.assertEqual(nd[str(REALLY_HUGE)], 'largest')
+        self.assertEqual(nd[repr(E)], "Euler's number")
+        self.assertEqual(nd[repr(PI)], 'pi')
+        self.assertEqual(nd[repr(TAU)], 'tau')
+        self.assertEqual(nd['Infinity'], 'Infinity')
+        self.assertEqual(nd['-Infinity'], '-Infinity')
+        self.assertEqual(nd['NaN'], 'NaN')
+
+    def test_dict_values(self):
+        d = dict(
+                tiny=BigNum.small,
+                large=BigNum.big,
+                larger=BigNum.huge,
+                largest=BigNum.really_huge,
+                e=FloatNum.e,
+                pi=FloatNum.pi,
+                tau=FloatNum.tau,
+                i=WierdNum.inf,
+                j=WierdNum.neg_inf,
+                n=WierdNum.nan,
+                )
+        nd = self.loads(self.dumps(d))
+        self.assertEqual(nd['tiny'], SMALL)
+        self.assertEqual(nd['large'], BIG)
+        self.assertEqual(nd['larger'], HUGE)
+        self.assertEqual(nd['largest'], REALLY_HUGE)
+        self.assertEqual(nd['e'], E)
+        self.assertEqual(nd['pi'], PI)
+        self.assertEqual(nd['tau'], TAU)
+        self.assertEqual(nd['i'], INF)
+        self.assertEqual(nd['j'], NEG_INF)
+        self.assertTrue(isnan(nd['n']))
+
+# class TestPyEnum(_TestEnum, PyTest): pass
+# class TestCEnum(_TestEnum, CTest): pass
+class TestRustEnum(_TestEnum, RustTest): pass
diff --git a/tests/cpython/test_fail.py b/tests/cpython/test_fail.py
new file mode 100644
index 0000000..7236c72
--- /dev/null
+++ b/tests/cpython/test_fail.py
@@ -0,0 +1,217 @@
+from cpython import PyTest, CTest, RustTest
+
+# 2007-10-05
+JSONDOCS = [
+    # http://json.org/JSON_checker/test/fail1.json
+    '"A JSON payload should be an object or array, not a string."',
+    # http://json.org/JSON_checker/test/fail2.json
+    '["Unclosed array"',
+    # http://json.org/JSON_checker/test/fail3.json
+    '{unquoted_key: "keys must be quoted"}',
+    # http://json.org/JSON_checker/test/fail4.json
+    '["extra comma",]',
+    # http://json.org/JSON_checker/test/fail5.json
+    '["double extra comma",,]',
+    # http://json.org/JSON_checker/test/fail6.json
+    '[   , "<-- missing value"]',
+    # http://json.org/JSON_checker/test/fail7.json
+    '["Comma after the close"],',
+    # http://json.org/JSON_checker/test/fail8.json
+    '["Extra close"]]',
+    # http://json.org/JSON_checker/test/fail9.json
+    '{"Extra comma": true,}',
+    # http://json.org/JSON_checker/test/fail10.json
+    '{"Extra value after close": true} "misplaced quoted value"',
+    # http://json.org/JSON_checker/test/fail11.json
+    '{"Illegal expression": 1 + 2}',
+    # http://json.org/JSON_checker/test/fail12.json
+    '{"Illegal invocation": alert()}',
+    # http://json.org/JSON_checker/test/fail13.json
+    '{"Numbers cannot have leading zeroes": 013}',
+    # http://json.org/JSON_checker/test/fail14.json
+    '{"Numbers cannot be hex": 0x14}',
+    # http://json.org/JSON_checker/test/fail15.json
+    '["Illegal backslash escape: \\x15"]',
+    # http://json.org/JSON_checker/test/fail16.json
+    '[\\naked]',
+    # http://json.org/JSON_checker/test/fail17.json
+    '["Illegal backslash escape: \\017"]',
+    # http://json.org/JSON_checker/test/fail18.json
+    '[[[[[[[[[[[[[[[[[[[["Too deep"]]]]]]]]]]]]]]]]]]]]',
+    # http://json.org/JSON_checker/test/fail19.json
+    '{"Missing colon" null}',
+    # http://json.org/JSON_checker/test/fail20.json
+    '{"Double colon":: null}',
+    # http://json.org/JSON_checker/test/fail21.json
+    '{"Comma instead of colon", null}',
+    # http://json.org/JSON_checker/test/fail22.json
+    '["Colon instead of comma": false]',
+    # http://json.org/JSON_checker/test/fail23.json
+    '["Bad value", truth]',
+    # http://json.org/JSON_checker/test/fail24.json
+    "['single quote']",
+    # http://json.org/JSON_checker/test/fail25.json
+    '["\ttab\tcharacter\tin\tstring\t"]',
+    # http://json.org/JSON_checker/test/fail26.json
+    '["tab\\   character\\   in\\  string\\  "]',
+    # http://json.org/JSON_checker/test/fail27.json
+    '["line\nbreak"]',
+    # http://json.org/JSON_checker/test/fail28.json
+    '["line\\\nbreak"]',
+    # http://json.org/JSON_checker/test/fail29.json
+    '[0e]',
+    # http://json.org/JSON_checker/test/fail30.json
+    '[0e+]',
+    # http://json.org/JSON_checker/test/fail31.json
+    '[0e+-1]',
+    # http://json.org/JSON_checker/test/fail32.json
+    '{"Comma instead if closing brace": true,',
+    # http://json.org/JSON_checker/test/fail33.json
+    '["mismatch"}',
+    # http://code.google.com/p/simplejson/issues/detail?id=3
+    '["A\u001FZ control characters in string"]',
+]
+
+SKIPS = {
+    1: "why not have a string payload?",
+    18: "spec doesn't specify any nesting limitations",
+}
+
+class _TestFail:
+    def test_failures(self):
+        for idx, doc in enumerate(JSONDOCS):
+            idx = idx + 1
+            if idx in SKIPS:
+                self.loads(doc)
+                continue
+            try:
+                self.loads(doc)
+            except self.JSONDecodeError:
+                pass
+            else:
+                self.fail("Expected failure for fail{0}.json: {1!r}".format(idx, doc))
+
+    def test_non_string_keys_dict(self):
+        data = {'a' : 1, (1, 2) : 2}
+
+        #This is for c encoder
+        self.assertRaises(TypeError, self.dumps, data)
+
+        #This is for python encoder
+        self.assertRaises(TypeError, self.dumps, data, indent=True)
+
+    def test_truncated_input(self):
+        test_cases = [
+            ('', 'Expecting value', 0),
+            ('[', 'Expecting value', 1),
+            ('[42', "Expecting ',' delimiter", 3),
+            ('[42,', 'Expecting value', 4),
+            ('["', 'Unterminated string starting at', 1),
+            ('["spam', 'Unterminated string starting at', 1),
+            ('["spam"', "Expecting ',' delimiter", 7),
+            ('["spam",', 'Expecting value', 8),
+            ('{', 'Expecting property name enclosed in double quotes', 1),
+            ('{"', 'Unterminated string starting at', 1),
+            ('{"spam', 'Unterminated string starting at', 1),
+            ('{"spam"', "Expecting ':' delimiter", 7),
+            ('{"spam":', 'Expecting value', 8),
+            ('{"spam":42', "Expecting ',' delimiter", 10),
+            ('{"spam":42,', 'Expecting property name enclosed in double quotes', 11),
+        ]
+        test_cases += [
+            ('"', 'Unterminated string starting at', 0),
+            ('"spam', 'Unterminated string starting at', 0),
+        ]
+        for data, msg, idx in test_cases:
+            with self.assertRaises(self.JSONDecodeError) as cm:
+                self.loads(data)
+            err = cm.exception
+            self.assertEqual(err.msg, msg)
+            self.assertEqual(err.pos, idx)
+            self.assertEqual(err.lineno, 1)
+            self.assertEqual(err.colno, idx + 1)
+            self.assertEqual(str(err),
+                             '%s: line 1 column %d (char %d)' %
+                             (msg, idx + 1, idx))
+
+    def test_unexpected_data(self):
+        test_cases = [
+            ('[,', 'Expecting value', 1),
+            ('{"spam":[}', 'Expecting value', 9),
+            ('[42:', "Expecting ',' delimiter", 3),
+            ('[42 "spam"', "Expecting ',' delimiter", 4),
+            ('[42,]', 'Expecting value', 4),
+            ('{"spam":[42}', "Expecting ',' delimiter", 11),
+            ('["]', 'Unterminated string starting at', 1),
+            ('["spam":', "Expecting ',' delimiter", 7),
+            ('["spam",]', 'Expecting value', 8),
+            ('{:', 'Expecting property name enclosed in double quotes', 1),
+            ('{,', 'Expecting property name enclosed in double quotes', 1),
+            ('{42', 'Expecting property name enclosed in double quotes', 1),
+            ('[{]', 'Expecting property name enclosed in double quotes', 2),
+            ('{"spam",', "Expecting ':' delimiter", 7),
+            ('{"spam"}', "Expecting ':' delimiter", 7),
+            ('[{"spam"]', "Expecting ':' delimiter", 8),
+            ('{"spam":}', 'Expecting value', 8),
+            ('[{"spam":]', 'Expecting value', 9),
+            ('{"spam":42 "ham"', "Expecting ',' delimiter", 11),
+            ('[{"spam":42]', "Expecting ',' delimiter", 11),
+            ('{"spam":42,}', 'Expecting property name enclosed in double quotes', 11),
+        ]
+        for data, msg, idx in test_cases:
+            with self.assertRaises(self.JSONDecodeError) as cm:
+                self.loads(data)
+            err = cm.exception
+            self.assertEqual(err.msg, msg)
+            self.assertEqual(err.pos, idx)
+            self.assertEqual(err.lineno, 1)
+            self.assertEqual(err.colno, idx + 1)
+            self.assertEqual(str(err),
+                             '%s: line 1 column %d (char %d)' %
+                             (msg, idx + 1, idx))
+
+    def test_extra_data(self):
+        test_cases = [
+            ('[]]', 'Extra data', 2),
+            ('{}}', 'Extra data', 2),
+            ('[],[]', 'Extra data', 2),
+            ('{},{}', 'Extra data', 2),
+        ]
+        test_cases += [
+            ('42,"spam"', 'Extra data', 2),
+            ('"spam",42', 'Extra data', 6),
+        ]
+        for data, msg, idx in test_cases:
+            with self.assertRaises(self.JSONDecodeError) as cm:
+                self.loads(data)
+            err = cm.exception
+            self.assertEqual(err.msg, msg)
+            self.assertEqual(err.pos, idx)
+            self.assertEqual(err.lineno, 1)
+            self.assertEqual(err.colno, idx + 1)
+            self.assertEqual(str(err),
+                             '%s: line 1 column %d (char %d)' %
+                             (msg, idx + 1, idx))
+
+    def test_linecol(self):
+        test_cases = [
+            ('!', 1, 1, 0),
+            (' !', 1, 2, 1),
+            ('\n!', 2, 1, 1),
+            ('\n  \n\n     !', 4, 6, 10),
+        ]
+        for data, line, col, idx in test_cases:
+            with self.assertRaises(self.JSONDecodeError) as cm:
+                self.loads(data)
+            err = cm.exception
+            self.assertEqual(err.msg, 'Expecting value')
+            self.assertEqual(err.pos, idx)
+            self.assertEqual(err.lineno, line)
+            self.assertEqual(err.colno, col)
+            self.assertEqual(str(err),
+                             'Expecting value: line %s column %d (char %d)' %
+                             (line, col, idx))
+
+# class TestPyFail(_TestFail, PyTest): pass
+# class TestCFail(_TestFail, CTest): pass
+class TestRustFail(_TestFail, RustTest): pass
diff --git a/tests/cpython/test_float.py b/tests/cpython/test_float.py
new file mode 100644
index 0000000..a94ccf3
--- /dev/null
+++ b/tests/cpython/test_float.py
@@ -0,0 +1,34 @@
+import math
+from cpython import PyTest, CTest, RustTest
+
+
+class _TestFloat:
+    def test_floats(self):
+        for num in [1617161771.7650001, math.pi, math.pi**100, math.pi**-100, 3.1]:
+            self.assertEqual(float(self.dumps(num)), num)
+            self.assertEqual(self.loads(self.dumps(num)), num)
+
+    def test_ints(self):
+        for num in [1, 1<<32, 1<<64]:
+            self.assertEqual(self.dumps(num), str(num))
+            self.assertEqual(int(self.dumps(num)), num)
+
+    def test_out_of_range(self):
+        self.assertEqual(self.loads('[23456789012E666]'), [float('inf')])
+        self.assertEqual(self.loads('[-23456789012E666]'), [float('-inf')])
+
+    def test_allow_nan(self):
+        for val in (float('inf'), float('-inf'), float('nan')):
+            out = self.dumps([val])
+            if val == val:  # inf
+                self.assertEqual(self.loads(out), [val])
+            else:  # nan
+                res = self.loads(out)
+                self.assertEqual(len(res), 1)
+                self.assertNotEqual(res[0], res[0])
+            self.assertRaises(ValueError, self.dumps, [val], allow_nan=False)
+
+
+# class TestPyFloat(_TestFloat, PyTest): pass
+# class TestCFloat(_TestFloat, CTest): pass
+class TestRustFloat(_TestFloat, RustTest): pass
diff --git a/tests/cpython/test_indent.py b/tests/cpython/test_indent.py
new file mode 100644
index 0000000..8cc701f
--- /dev/null
+++ b/tests/cpython/test_indent.py
@@ -0,0 +1,68 @@
+import textwrap
+from io import StringIO
+from cpython import PyTest, CTest, RustTest
+
+
+class _TestIndent:
+    def test_indent(self):
+        h = [['blorpie'], ['whoops'], [], 'd-shtaeou', 'd-nthiouh', 'i-vhbjkhnth',
+             {'nifty': 87}, {'field': 'yes', 'morefield': False} ]
+
+        expect = textwrap.dedent("""\
+        [
+        \t[
+        \t\t"blorpie"
+        \t],
+        \t[
+        \t\t"whoops"
+        \t],
+        \t[],
+        \t"d-shtaeou",
+        \t"d-nthiouh",
+        \t"i-vhbjkhnth",
+        \t{
+        \t\t"nifty": 87
+        \t},
+        \t{
+        \t\t"field": "yes",
+        \t\t"morefield": false
+        \t}
+        ]""")
+
+        d1 = self.dumps(h)
+        d2 = self.dumps(h, indent=2, sort_keys=True, separators=(',', ': '))
+        d3 = self.dumps(h, indent='\t', sort_keys=True, separators=(',', ': '))
+        d4 = self.dumps(h, indent=2, sort_keys=True)
+        d5 = self.dumps(h, indent='\t', sort_keys=True)
+
+        h1 = self.loads(d1)
+        h2 = self.loads(d2)
+        h3 = self.loads(d3)
+
+        self.assertEqual(h1, h)
+        self.assertEqual(h2, h)
+        self.assertEqual(h3, h)
+        self.assertEqual(d2, expect.expandtabs(2))
+        self.assertEqual(d3, expect)
+        self.assertEqual(d4, d2)
+        self.assertEqual(d5, d3)
+
+    def test_indent0(self):
+        h = {3: 1}
+        def check(indent, expected):
+            d1 = self.dumps(h, indent=indent)
+            self.assertEqual(d1, expected)
+
+            sio = StringIO()
+            self.json.dump(h, sio, indent=indent)
+            self.assertEqual(sio.getvalue(), expected)
+
+        # indent=0 should emit newlines
+        check(0, '{\n"3": 1\n}')
+        # indent=None is more compact
+        check(None, '{"3": 1}')
+
+
+# class TestPyIndent(_TestIndent, PyTest): pass
+# class TestCIndent(_TestIndent, CTest): pass
+class TestRustIndent(_TestIndent, RustTest): pass
diff --git a/tests/cpython/test_pass1.py b/tests/cpython/test_pass1.py
new file mode 100644
index 0000000..1039af2
--- /dev/null
+++ b/tests/cpython/test_pass1.py
@@ -0,0 +1,76 @@
+from cpython import PyTest, CTest, RustTest
+
+
+# from http://json.org/JSON_checker/test/pass1.json
+JSON = r'''
+[
+    "JSON Test Pattern pass1",
+    {"object with 1 member":["array with 1 element"]},
+    {},
+    [],
+    -42,
+    true,
+    false,
+    null,
+    {
+        "integer": 1234567890,
+        "real": -9876.543210,
+        "e": 0.123456789e-12,
+        "E": 1.234567890E+34,
+        "":  23456789012E66,
+        "zero": 0,
+        "one": 1,
+        "space": " ",
+        "quote": "\"",
+        "backslash": "\\",
+        "controls": "\b\f\n\r\t",
+        "slash": "/ & \/",
+        "alpha": "abcdefghijklmnopqrstuvwyz",
+        "ALPHA": "ABCDEFGHIJKLMNOPQRSTUVWYZ",
+        "digit": "0123456789",
+        "0123456789": "digit",
+        "special": "`1~!@#$%^&*()_+-={':[,]}|;.</>?",
+        "hex": "\u0123\u4567\u89AB\uCDEF\uabcd\uef4A",
+        "true": true,
+        "false": false,
+        "null": null,
+        "array":[  ],
+        "object":{  },
+        "address": "50 St. James Street",
+        "url": "http://www.JSON.org/",
+        "comment": "// /* <!-- --",
+        "# -- --> */": " ",
+        " s p a c e d " :[1,2 , 3
+
+,
+
+4 , 5        ,          6           ,7        ],"compact":[1,2,3,4,5,6,7],
+        "jsontext": "{\"object with 1 member\":[\"array with 1 element\"]}",
+        "quotes": "&#34; \u0022 %22 0x22 034 &#x22;",
+        "\/\\\"\uCAFE\uBABE\uAB98\uFCDE\ubcda\uef4A\b\f\n\r\t`1~!@#$%^&*()_+-=[]{}|;:',./<>?"
+: "A key can be any string"
+    },
+    0.5 ,98.6
+,
+99.44
+,
+
+1066,
+1e1,
+0.1e1,
+1e-1,
+1e00,2e+00,2e-00
+,"rosebud"]
+'''
+
+class _TestPass1:
+    def test_parse(self):
+        # test in/out equivalence and parsing
+        res = self.loads(JSON)
+        out = self.dumps(res)
+        self.assertEqual(res, self.loads(out))
+
+
+# class TestPyPass1(_TestPass1, PyTest): pass
+# class TestCPass1(_TestPass1, CTest): pass
+class TestRustPass1(_TestPass1, RustTest): pass
diff --git a/tests/cpython/test_pass2.py b/tests/cpython/test_pass2.py
new file mode 100644
index 0000000..2649cca
--- /dev/null
+++ b/tests/cpython/test_pass2.py
@@ -0,0 +1,19 @@
+from cpython import PyTest, CTest, RustTest
+
+
+# from http://json.org/JSON_checker/test/pass2.json
+JSON = r'''
+[[[[[[[[[[[[[[[[[[["Not too deep"]]]]]]]]]]]]]]]]]]]
+'''
+
+class _TestPass2:
+    def test_parse(self):
+        # test in/out equivalence and parsing
+        res = self.loads(JSON)
+        out = self.dumps(res)
+        self.assertEqual(res, self.loads(out))
+
+
+# class TestPyPass2(_TestPass2, PyTest): pass
+# class TestCPass2(_TestPass2, CTest): pass
+class TestRustPass2(_TestPass2, RustTest): pass
diff --git a/tests/cpython/test_pass3.py b/tests/cpython/test_pass3.py
new file mode 100644
index 0000000..7675ca6
--- /dev/null
+++ b/tests/cpython/test_pass3.py
@@ -0,0 +1,25 @@
+from cpython import PyTest, CTest, RustTest
+
+
+# from http://json.org/JSON_checker/test/pass3.json
+JSON = r'''
+{
+    "JSON Test Pattern pass3": {
+        "The outermost value": "must be an object or array.",
+        "In this test": "It is an object."
+    }
+}
+'''
+
+
+class _TestPass3:
+    def test_parse(self):
+        # test in/out equivalence and parsing
+        res = self.loads(JSON)
+        out = self.dumps(res)
+        self.assertEqual(res, self.loads(out))
+
+
+# class TestPyPass3(_TestPass3, PyTest): pass
+# class TestCPass3(_TestPass3, CTest): pass
+class TestRustPass3(_TestPass3, RustTest): pass
diff --git a/tests/cpython/test_recursion.py b/tests/cpython/test_recursion.py
new file mode 100644
index 0000000..4826994
--- /dev/null
+++ b/tests/cpython/test_recursion.py
@@ -0,0 +1,103 @@
+from cpython import PyTest, CTest, RustTest
+
+
+class JSONTestObject:
+    pass
+
+
+class _TestRecursion:
+    def test_listrecursion(self):
+        x = []
+        x.append(x)
+        try:
+            self.dumps(x)
+        except ValueError:
+            pass
+        else:
+            self.fail("didn't raise ValueError on list recursion")
+        x = []
+        y = [x]
+        x.append(y)
+        try:
+            self.dumps(x)
+        except ValueError:
+            pass
+        else:
+            self.fail("didn't raise ValueError on alternating list recursion")
+        y = []
+        x = [y, y]
+        # ensure that the marker is cleared
+        self.dumps(x)
+
+    def test_dictrecursion(self):
+        x = {}
+        x["test"] = x
+        try:
+            self.dumps(x)
+        except ValueError:
+            pass
+        else:
+            self.fail("didn't raise ValueError on dict recursion")
+        x = {}
+        y = {"a": x, "b": x}
+        # ensure that the marker is cleared
+        self.dumps(x)
+
+    def test_defaultrecursion(self):
+        class RecursiveJSONEncoder(self.json.JSONEncoder):
+            recurse = False
+            def default(self, o):
+                if o is JSONTestObject:
+                    if self.recurse:
+                        return [JSONTestObject]
+                    else:
+                        return 'JSONTestObject'
+                return pyjson.JSONEncoder.default(o)
+
+        enc = RecursiveJSONEncoder()
+        self.assertEqual(enc.encode(JSONTestObject), '"JSONTestObject"')
+        enc.recurse = True
+        try:
+            enc.encode(JSONTestObject)
+        except ValueError:
+            pass
+        else:
+            self.fail("didn't raise ValueError on default recursion")
+
+
+    def test_highly_nested_objects_decoding(self):
+        # test that loading highly-nested objects doesn't segfault when C
+        # accelerations are used. See #12017
+        with self.assertRaises(RecursionError):
+            self.loads('{"a":' * 100000 + '1' + '}' * 100000)
+        with self.assertRaises(RecursionError):
+            self.loads('{"a":' * 100000 + '[1]' + '}' * 100000)
+        with self.assertRaises(RecursionError):
+            self.loads('[' * 100000 + '1' + ']' * 100000)
+
+    def test_highly_nested_objects_encoding(self):
+        # See #12051
+        l, d = [], {}
+        for x in range(100000):
+            l, d = [l], {'k':d}
+        with self.assertRaises(RecursionError):
+            self.dumps(l)
+        with self.assertRaises(RecursionError):
+            self.dumps(d)
+
+    def test_endless_recursion(self):
+        # See #12051
+        class EndlessJSONEncoder(self.json.JSONEncoder):
+            def default(self, o):
+                """If check_circular is False, this will keep adding another list."""
+                return [o]
+
+        with self.assertRaises(RecursionError):
+            EndlessJSONEncoder(check_circular=False).encode(5j)
+
+
+# class TestPyRecursion(_TestRecursion, PyTest): pass
+# class TestCRecursion(_TestRecursion, CTest): pass
+
+# FIXME: this will crash hyperjson
+# class TestRustRecursion(_TestRecursion, RustTest): pass
diff --git a/tests/cpython/test_scanstring.py b/tests/cpython/test_scanstring.py
new file mode 100644
index 0000000..90ad8e6
--- /dev/null
+++ b/tests/cpython/test_scanstring.py
@@ -0,0 +1,142 @@
+import sys
+from cpython import PyTest, CTest, RustTest
+
+
+class _TestScanstring:
+    def test_scanstring(self):
+        scanstring = self.json.decoder.scanstring
+        self.assertEqual(
+            scanstring('"z\U0001d120x"', 1, True),
+            ('z\U0001d120x', 5))
+
+        self.assertEqual(
+            scanstring('"\\u007b"', 1, True),
+            ('{', 8))
+
+        self.assertEqual(
+            scanstring('"A JSON payload should be an object or array, not a string."', 1, True),
+            ('A JSON payload should be an object or array, not a string.', 60))
+
+        self.assertEqual(
+            scanstring('["Unclosed array"', 2, True),
+            ('Unclosed array', 17))
+
+        self.assertEqual(
+            scanstring('["extra comma",]', 2, True),
+            ('extra comma', 14))
+
+        self.assertEqual(
+            scanstring('["double extra comma",,]', 2, True),
+            ('double extra comma', 21))
+
+        self.assertEqual(
+            scanstring('["Comma after the close"],', 2, True),
+            ('Comma after the close', 24))
+
+        self.assertEqual(
+            scanstring('["Extra close"]]', 2, True),
+            ('Extra close', 14))
+
+        self.assertEqual(
+            scanstring('{"Extra comma": true,}', 2, True),
+            ('Extra comma', 14))
+
+        self.assertEqual(
+            scanstring('{"Extra value after close": true} "misplaced quoted value"', 2, True),
+            ('Extra value after close', 26))
+
+        self.assertEqual(
+            scanstring('{"Illegal expression": 1 + 2}', 2, True),
+            ('Illegal expression', 21))
+
+        self.assertEqual(
+            scanstring('{"Illegal invocation": alert()}', 2, True),
+            ('Illegal invocation', 21))
+
+        self.assertEqual(
+            scanstring('{"Numbers cannot have leading zeroes": 013}', 2, True),
+            ('Numbers cannot have leading zeroes', 37))
+
+        self.assertEqual(
+            scanstring('{"Numbers cannot be hex": 0x14}', 2, True),
+            ('Numbers cannot be hex', 24))
+
+        self.assertEqual(
+            scanstring('[[[[[[[[[[[[[[[[[[[["Too deep"]]]]]]]]]]]]]]]]]]]]', 21, True),
+            ('Too deep', 30))
+
+        self.assertEqual(
+            scanstring('{"Missing colon" null}', 2, True),
+            ('Missing colon', 16))
+
+        self.assertEqual(
+            scanstring('{"Double colon":: null}', 2, True),
+            ('Double colon', 15))
+
+        self.assertEqual(
+            scanstring('{"Comma instead of colon", null}', 2, True),
+            ('Comma instead of colon', 25))
+
+        self.assertEqual(
+            scanstring('["Colon instead of comma": false]', 2, True),
+            ('Colon instead of comma', 25))
+
+        self.assertEqual(
+            scanstring('["Bad value", truth]', 2, True),
+            ('Bad value', 12))
+
+    def test_surrogates(self):
+        scanstring = self.json.decoder.scanstring
+        def assertScan(given, expect):
+            self.assertEqual(scanstring(given, 1, True),
+                             (expect, len(given)))
+
+        assertScan('"z\\ud834\\u0079x"', 'z\ud834yx')
+        assertScan('"z\\ud834\\udd20x"', 'z\U0001d120x')
+        assertScan('"z\\ud834\\ud834\\udd20x"', 'z\ud834\U0001d120x')
+        assertScan('"z\\ud834x"', 'z\ud834x')
+        assertScan('"z\\ud834\udd20x12345"', 'z\ud834\udd20x12345')
+        assertScan('"z\\udd20x"', 'z\udd20x')
+        assertScan('"z\ud834\udd20x"', 'z\ud834\udd20x')
+        assertScan('"z\ud834\\udd20x"', 'z\ud834\udd20x')
+        assertScan('"z\ud834x"', 'z\ud834x')
+
+    def test_bad_escapes(self):
+        scanstring = self.json.decoder.scanstring
+        bad_escapes = [
+            '"\\"',
+            '"\\x"',
+            '"\\u"',
+            '"\\u0"',
+            '"\\u01"',
+            '"\\u012"',
+            '"\\uz012"',
+            '"\\u0z12"',
+            '"\\u01z2"',
+            '"\\u012z"',
+            '"\\u0x12"',
+            '"\\u0X12"',
+            '"\\ud834\\"',
+            '"\\ud834\\u"',
+            '"\\ud834\\ud"',
+            '"\\ud834\\udd"',
+            '"\\ud834\\udd2"',
+            '"\\ud834\\uzdd2"',
+            '"\\ud834\\udzd2"',
+            '"\\ud834\\uddz2"',
+            '"\\ud834\\udd2z"',
+            '"\\ud834\\u0x20"',
+            '"\\ud834\\u0X20"',
+        ]
+        for s in bad_escapes:
+            with self.assertRaises(self.JSONDecodeError, msg=s):
+                scanstring(s, 1, True)
+
+    def test_overflow(self):
+        with self.assertRaises(OverflowError):
+            self.json.decoder.scanstring(b"xxx", sys.maxsize+1)
+
+
+# class TestPyScanstring(_TestScanstring, PyTest): pass
+# class TestCScanstring(_TestScanstring, CTest): pass
+class TestRustScanstring(_TestScanstring, RustTest): pass
diff --git a/tests/cpython/test_separators.py b/tests/cpython/test_separators.py
new file mode 100644
index 0000000..12bbaab
--- /dev/null
+++ b/tests/cpython/test_separators.py
@@ -0,0 +1,51 @@
+import textwrap
+from cpython import PyTest, CTest, RustTest
+
+
+class _TestSeparators:
+    def test_separators(self):
+        h = [['blorpie'], ['whoops'], [], 'd-shtaeou', 'd-nthiouh', 'i-vhbjkhnth',
+             {'nifty': 87}, {'field': 'yes', 'morefield': False} ]
+
+        expect = textwrap.dedent("""\
+        [
+          [
+            "blorpie"
+          ] ,
+          [
+            "whoops"
+          ] ,
+          [] ,
+          "d-shtaeou" ,
+          "d-nthiouh" ,
+          "i-vhbjkhnth" ,
+          {
+            "nifty" : 87
+          } ,
+          {
+            "field" : "yes" ,
+            "morefield" : false
+          }
+        ]""")
+
+
+        d1 = self.dumps(h)
+        d2 = self.dumps(h, indent=2, sort_keys=True, separators=(' ,', ' : '))
+
+        h1 = self.loads(d1)
+        h2 = self.loads(d2)
+
+        self.assertEqual(h1, h)
+        self.assertEqual(h2, h)
+        self.assertEqual(d2, expect)
+
+    def test_illegal_separators(self):
+        h = {1: 2, 3: 4}
+        self.assertRaises(TypeError, self.dumps, h, separators=(b', ', ': '))
+        self.assertRaises(TypeError, self.dumps, h, separators=(', ', b': '))
+        self.assertRaises(TypeError, self.dumps, h, separators=(b', ', b': '))
+
+
+# class TestPySeparators(_TestSeparators, PyTest): pass
+# class TestCSeparators(_TestSeparators, CTest): pass
+class TestRustSeparators(_TestSeparators, RustTest): pass
diff --git a/tests/cpython/test_speedups.py b/tests/cpython/test_speedups.py
new file mode 100644
index 0000000..1ba94de
--- /dev/null
+++ b/tests/cpython/test_speedups.py
@@ -0,0 +1,71 @@
+from cpython import CTest
+
+
+class BadBool:
+    def __bool__(self):
+        1/0
+
+
+class TestSpeedups(CTest):
+    def test_scanstring(self):
+        self.assertEqual(self.json.decoder.scanstring.__module__, "_json")
+        self.assertIs(self.json.decoder.scanstring, self.json.decoder.c_scanstring)
+
+    def test_encode_basestring_ascii(self):
+        self.assertEqual(self.json.encoder.encode_basestring_ascii.__module__,
+                         "_json")
+        self.assertIs(self.json.encoder.encode_basestring_ascii,
+                      self.json.encoder.c_encode_basestring_ascii)
+
+
+class TestDecode(CTest):
+    def test_make_scanner(self):
+        self.assertRaises(AttributeError, self.json.scanner.c_make_scanner, 1)
+
+    def test_bad_bool_args(self):
+        def test(value):
+            self.json.decoder.JSONDecoder(strict=BadBool()).decode(value)
+        self.assertRaises(ZeroDivisionError, test, '""')
+        self.assertRaises(ZeroDivisionError, test, '{}')
+
+
+class TestEncode(CTest):
+    def test_make_encoder(self):
+        self.assertRaises(TypeError, self.json.encoder.c_make_encoder,
+            (True, False),
+            b"\xCD\x7D\x3D\x4E\x12\x4C\xF9\x79\xD7\x52\xBA\x82\xF2\x27\x4A\x7D\xA0\xCA\x75",
+            None)
+
+    def test_bad_str_encoder(self):
+        # Issue #31505: There shouldn't be an assertion failure in case
+        # c_make_encoder() receives a bad encoder() argument.
+        def bad_encoder1(*args):
+            return None
+        enc = self.json.encoder.c_make_encoder(None, lambda obj: str(obj),
+                                               bad_encoder1, None, ': ', ', ',
+                                               False, False, False)
+        with self.assertRaises(TypeError):
+            enc('spam', 4)
+        with self.assertRaises(TypeError):
+            enc({'spam': 42}, 4)
+
+        def bad_encoder2(*args):
+            1/0
+        enc = self.json.encoder.c_make_encoder(None, lambda obj: str(obj),
+                                               bad_encoder2, None, ': ', ', ',
+                                               False, False, False)
+        with self.assertRaises(ZeroDivisionError):
+            enc('spam', 4)
+
+    def test_bad_bool_args(self):
+        def test(name):
+            self.json.encoder.JSONEncoder(**{name: BadBool()}).encode({'a': 1})
+        self.assertRaises(ZeroDivisionError, test, 'skipkeys')
+        self.assertRaises(ZeroDivisionError, test, 'ensure_ascii')
+        self.assertRaises(ZeroDivisionError, test, 'check_circular')
+        self.assertRaises(ZeroDivisionError, test, 'allow_nan')
+        self.assertRaises(ZeroDivisionError, test, 'sort_keys')
+
+    def test_unsortable_keys(self):
+        with self.assertRaises(TypeError):
+            self.json.encoder.JSONEncoder(sort_keys=True).encode({'a': 1, 1: 'a'})
diff --git a/tests/cpython/test_tool.py b/tests/cpython/test_tool.py
new file mode 100644
index 0000000..9d93f93
--- /dev/null
+++ b/tests/cpython/test_tool.py
@@ -0,0 +1,107 @@
+import os
+import sys
+import textwrap
+import unittest
+from subprocess import Popen, PIPE
+from test import support
+from test.support.script_helper import assert_python_ok
+
+
+class TestTool(unittest.TestCase):
+    data = """
+
+        [["blorpie"],[ "whoops" ] , [
+                                 ],\t"d-shtaeou",\r"d-nthiouh",
+        "i-vhbjkhnth", {"nifty":87}, {"morefield" :\tfalse,"field"
+            :"yes"}  ]
+           """
+
+    expect_without_sort_keys = textwrap.dedent("""\
+    [
+        [
+            "blorpie"
+        ],
+        [
+            "whoops"
+        ],
+        [],
+        "d-shtaeou",
+        "d-nthiouh",
+        "i-vhbjkhnth",
+        {
+            "nifty": 87
+        },
+        {
+            "field": "yes",
+            "morefield": false
+        }
+    ]
+    """)
+
+    expect = textwrap.dedent("""\
+    [
+        [
+            "blorpie"
+        ],
+        [
+            "whoops"
+        ],
+        [],
+        "d-shtaeou",
+        "d-nthiouh",
+        "i-vhbjkhnth",
+        {
+            "nifty": 87
+        },
+        {
+            "morefield": false,
+            "field": "yes"
+        }
+    ]
+    """)
+
+    def test_stdin_stdout(self):
+        args = sys.executable, '-m', 'json.tool'
+        with Popen(args, stdin=PIPE, stdout=PIPE, stderr=PIPE) as proc:
+            out, err = proc.communicate(self.data.encode())
+        self.assertEqual(out.splitlines(), self.expect.encode().splitlines())
+        self.assertEqual(err, b'')
+
+    def _create_infile(self):
+        infile = support.TESTFN
+        with open(infile, "w") as fp:
+            self.addCleanup(os.remove, infile)
+            fp.write(self.data)
+        return infile
+
+    def test_infile_stdout(self):
+        infile = self._create_infile()
+        rc, out, err = assert_python_ok('-m', 'json.tool', infile)
+        self.assertEqual(rc, 0)
+        self.assertEqual(out.splitlines(), self.expect.encode().splitlines())
+        self.assertEqual(err, b'')
+
+    def test_infile_outfile(self):
+        infile = self._create_infile()
+        outfile = support.TESTFN + '.out'
+        rc, out, err = assert_python_ok('-m', 'json.tool', infile, outfile)
+        self.addCleanup(os.remove, outfile)
+        with open(outfile, "r") as fp:
+            self.assertEqual(fp.read(), self.expect)
+        self.assertEqual(rc, 0)
+        self.assertEqual(out, b'')
+        self.assertEqual(err, b'')
+
+    def test_help_flag(self):
+        rc, out, err = assert_python_ok('-m', 'json.tool', '-h')
+        self.assertEqual(rc, 0)
+        self.assertTrue(out.startswith(b'usage: '))
+        self.assertEqual(err, b'')
+
+    def test_sort_keys_flag(self):
+        infile = self._create_infile()
+        rc, out, err = assert_python_ok('-m', 'json.tool', '--sort-keys', infile)
+        self.assertEqual(rc, 0)
+        self.assertEqual(out.splitlines(),
+                         self.expect_without_sort_keys.encode().splitlines())
+        self.assertEqual(err, b'')
diff --git a/tests/cpython/test_unicode.py b/tests/cpython/test_unicode.py
new file mode 100644
index 0000000..d327cb0
--- /dev/null
+++ b/tests/cpython/test_unicode.py
@@ -0,0 +1,99 @@
+import codecs
+from collections import OrderedDict
+from cpython import PyTest, CTest, RustTest
+
+
+class _TestUnicode:
+    # test_encoding1 and test_encoding2 from 2.x are irrelevant (only str
+    # is supported as input, not bytes).
+
+    def test_encoding3(self):
+        u = '\N{GREEK SMALL LETTER ALPHA}\N{GREEK CAPITAL LETTER OMEGA}'
+        j = self.dumps(u)
+        self.assertEqual(j, '"\\u03b1\\u03a9"')
+
+    def test_encoding4(self):
+        u = '\N{GREEK SMALL LETTER ALPHA}\N{GREEK CAPITAL LETTER OMEGA}'
+        j = self.dumps([u])
+        self.assertEqual(j, '["\\u03b1\\u03a9"]')
+
+    def test_encoding5(self):
+        u = '\N{GREEK SMALL LETTER ALPHA}\N{GREEK CAPITAL LETTER OMEGA}'
+        j = self.dumps(u, ensure_ascii=False)
+        self.assertEqual(j, '"{0}"'.format(u))
+
+    def test_encoding6(self):
+        u = '\N{GREEK SMALL LETTER ALPHA}\N{GREEK CAPITAL LETTER OMEGA}'
+        j = self.dumps([u], ensure_ascii=False)
+        self.assertEqual(j, '["{0}"]'.format(u))
+
+    def test_big_unicode_encode(self):
+        u = '\U0001d120'
+        self.assertEqual(self.dumps(u), '"\\ud834\\udd20"')
+        self.assertEqual(self.dumps(u, ensure_ascii=False), '"\U0001d120"')
+
+    def test_big_unicode_decode(self):
+        u = 'z\U0001d120x'
+        self.assertEqual(self.loads('"' + u + '"'), u)
+        self.assertEqual(self.loads('"z\\ud834\\udd20x"'), u)
+
+    def test_unicode_decode(self):
+        for i in range(0, 0xd7ff):
+            u = chr(i)
+            s = '"\\u{0:04x}"'.format(i)
+            self.assertEqual(self.loads(s), u)
+
+    def test_unicode_preservation(self):
+        self.assertEqual(type(self.loads('""')), str)
+        self.assertEqual(type(self.loads('"a"')), str)
+        self.assertEqual(type(self.loads('["a"]')[0]), str)
+
+    def test_bytes_encode(self):
+        self.assertRaises(TypeError, self.dumps, b"hi")
+        self.assertRaises(TypeError, self.dumps, [b"hi"])
+
+    def test_bytes_decode(self):
+        for encoding, bom in [
+                ('utf-8', codecs.BOM_UTF8),
+                ('utf-16be', codecs.BOM_UTF16_BE),
+                ('utf-16le', codecs.BOM_UTF16_LE),
+                ('utf-32be', codecs.BOM_UTF32_BE),
+                ('utf-32le', codecs.BOM_UTF32_LE),
+            ]:
+            data = ["a\xb5\u20ac\U0001d120"]
+            encoded = self.dumps(data).encode(encoding)
+            self.assertEqual(self.loads(bom + encoded), data)
+            self.assertEqual(self.loads(encoded), data)
+        self.assertRaises(UnicodeDecodeError, self.loads, b'["\x80"]')
+        # RFC-7159 and ECMA-404 extend JSON to allow documents that
+        # consist of only a string, which can present a special case
+        # not covered by the encoding detection patterns specified in
+        # RFC-4627 for utf-16-le (XX 00 XX 00).
+        self.assertEqual(self.loads('"\u2600"'.encode('utf-16-le')),
+                         '\u2600')
+        # Encoding detection for small (<4) bytes objects
+        # is implemented as a special case. RFC-7159 and ECMA-404
+        # allow single codepoint JSON documents which are only two
+        # bytes in utf-16 encodings w/o BOM.
+        self.assertEqual(self.loads(b'5\x00'), 5)
+        self.assertEqual(self.loads(b'\x007'), 7)
+        self.assertEqual(self.loads(b'57'), 57)
+
+    def test_object_pairs_hook_with_unicode(self):
+        s = '{"xkd":1, "kcw":2, "art":3, "hxm":4, "qrt":5, "pad":6, "hoy":7}'
+        p = [("xkd", 1), ("kcw", 2), ("art", 3), ("hxm", 4),
+             ("qrt", 5), ("pad", 6), ("hoy", 7)]
+        self.assertEqual(self.loads(s), eval(s))
+        self.assertEqual(self.loads(s, object_pairs_hook = lambda x: x), p)
+        od = self.loads(s, object_pairs_hook = OrderedDict)
+        self.assertEqual(od, OrderedDict(p))
+        self.assertEqual(type(od), OrderedDict)
+        # the object_pairs_hook takes priority over the object_hook
+        self.assertEqual(self.loads(s, object_pairs_hook = OrderedDict,
+                                    object_hook = lambda x: None),
+                         OrderedDict(p))
+
+
+# class TestPyUnicode(_TestUnicode, PyTest): pass
+# class TestCUnicode(_TestUnicode, CTest): pass
+class TestRustUnicode(_TestUnicode, RustTest): pass