Add tests for the C APIs PyCodec_IncrementalEncoder() and

PyCodec_IncrementalDecoder().

Lib/test/test_codecs.py

 from test import test_support
 import unittest
 import codecs
-import sys, StringIO
+import sys, StringIO, _testcapi
 
 class Queue(object):
     """
@@ -1032,9 +1032,11 @@ class BasicUnicodeTest(unittest.TestCase):
                     decodedresult += reader.read()
                 self.assertEqual(decodedresult, s, "%r != %r (encoding=%r)" % (decodedresult, s, encoding))
 
-                # check incremental decoder/encoder and iterencode()/iterdecode()
+                # check incremental decoder/encoder (fetched via the Python
+                # and C API) and iterencode()/iterdecode()
                 try:
                     encoder = codecs.getincrementalencoder(encoding)()
+                    cencoder = _testcapi.codec_incrementalencoder(encoding)
                 except LookupError: # no IncrementalEncoder
                     pass
                 else:
@@ -1048,6 +1050,16 @@ class BasicUnicodeTest(unittest.TestCase):
                         decodedresult += decoder.decode(c)
                     self.assertEqual(decodedresult, s, "%r != %r (encoding=%r)" % (decodedresult, s, encoding))
 
+                    # check C API
+                    encodedresult = ""
+                    for c in s:
+                        encodedresult += cencoder.encode(c)
+                    cdecoder = _testcapi.codec_incrementaldecoder(encoding)
+                    decodedresult = u""
+                    for c in encodedresult:
+                        decodedresult += cdecoder.decode(c)
+                    self.assertEqual(decodedresult, s, "%r != %r (encoding=%r)" % (decodedresult, s, encoding))
+
                     # check iterencode()/iterdecode()
                     result = u"".join(codecs.iterdecode(codecs.iterencode(s, encoding), encoding))
                     self.assertEqual(result, s, "%r != %r (encoding=%r)" % (result, s, encoding))

Modules/_testcapimodule.c

@@ -478,6 +478,26 @@ test_u_code(PyObject *self)
 	return Py_None;
 }
 
+static
+PyObject *codec_incrementalencoder(PyObject *self, PyObject *args)
+{
+	const char *encoding, *errors = NULL;
+	if (!PyArg_ParseTuple(args, "s|s:test_incrementalencoder", 
+			      &encoding, &errors))
+		return NULL;
+	return PyCodec_IncrementalEncoder(encoding, errors);
+}
+
+static
+PyObject *codec_incrementaldecoder(PyObject *self, PyObject *args)
+{
+	const char *encoding, *errors = NULL;
+	if (!PyArg_ParseTuple(args, "s|s:test_incrementaldecoder", 
+			      &encoding, &errors))
+		return NULL;
+	return PyCodec_IncrementalDecoder(encoding, errors);
+}
+
 #endif
 
 /* Simple test of _PyLong_NumBits and _PyLong_Sign. */
@@ -623,6 +643,10 @@ static PyMethodDef TestMethods[] = {
 	{"getargs_K",		(PyCFunction)getargs_K,		 METH_VARARGS},
 	{"test_longlong_api",	(PyCFunction)test_longlong_api,	 METH_NOARGS},
 	{"test_L_code",		(PyCFunction)test_L_code,	 METH_NOARGS},
+	{"codec_incrementalencoder",
+	 (PyCFunction)codec_incrementalencoder,	 METH_VARARGS},
+	{"codec_incrementaldecoder",
+	 (PyCFunction)codec_incrementaldecoder,	 METH_VARARGS},
 #endif
 #ifdef Py_USING_UNICODE
 	{"test_u_code",		(PyCFunction)test_u_code,	 METH_NOARGS},