Improve coverage of PyObject_Print

Lib/test/test_class.py

@@ -740,6 +740,77 @@ class A(0, 1, 2, 3, 4, 5, 6, 7, **d): pass
         class A(0, *range(1, 8), **d, foo='bar'): pass
         self.assertEqual(A, (tuple(range(8)), {'foo': 'bar'}))
 
+    def testPyObjectPrintObject(self):
+        import os
+        import test.support.os_helper as os_helper
+        from test.support import import_helper
+
+        _testcapi = import_helper.import_module('_testcapi')
+
+        class PrintableObject:
+
+            def __repr__(self):
+                return "spam spam spam"
+
+            def __str__(self):
+                return "egg egg egg"
+
+        obj = PrintableObject()
+        output_filename = os_helper.TESTFN
+        # Test repr printing
+        _testcapi.call_pyobject_print(obj, output_filename, False)
+        with open(output_filename, 'r') as output_file:
+            self.assertEqual(output_file.read(), repr(obj))
+        # Test str printing
+        _testcapi.call_pyobject_print(obj, output_filename, True)
+        with open(output_filename, 'r') as output_file:
+            self.assertEqual(output_file.read(), str(obj))
+
+        os.remove(output_filename)
+
+    def testPyObjectPrintNULL(self):
+        import os
+        import test.support.os_helper as os_helper
+        from test.support import import_helper
+
+        _testcapi = import_helper.import_module('_testcapi')
+
+        output_filename = os_helper.TESTFN
+        # Test repr printing
+        _testcapi.pyobject_print_null(output_filename)
+        with open(output_filename, 'r') as output_file:
+            self.assertEqual(output_file.read(), '<nil>')
+
+        os.remove(output_filename)
+
+    def testPyObjectPrintNoRefObject(self):
+        import os
+        import test.support.os_helper as os_helper
+        from test.support import import_helper
+
+        _testcapi = import_helper.import_module('_testcapi')
+
+        output_filename = os_helper.TESTFN
+        # Test repr printing
+        correct_output = _testcapi.pyobject_print_noref_object(output_filename)
+        with open(output_filename, 'r') as output_file:
+            self.assertEqual(output_file.read(), correct_output)
+
+        os.remove(output_filename)
+
+    def testPyObjectPrintOSError(self):
+        import os
+        import test.support.os_helper as os_helper
+        from test.support import import_helper
+
+        _testcapi = import_helper.import_module('_testcapi')
+
+        output_filename = os_helper.TESTFN
+        open(output_filename, "w+").close()
+        with self.assertRaises(OSError):
+            _testcapi.pyobject_print_os_error(output_filename)
+
+        os.remove(output_filename)
 
 if __name__ == '__main__':
     unittest.main()

Modules/_testcapimodule.c

@@ -2001,6 +2001,109 @@ pyobject_bytes_from_null(PyObject *self, PyObject *Py_UNUSED(ignored))
     return PyObject_Bytes(NULL);
 }
 
+static PyObject *
+call_pyobject_print(PyObject *self, PyObject * args)
+{
+    PyObject *object;
+    PyObject *filename;
+    PyObject *print_raw;
+    FILE *fp;
+    int flags = 0;
+
+    if (!PyArg_UnpackTuple(args, "call_pyobject_print", 3, 3, &object, &filename, &print_raw)) {
+        return NULL;
+    }
+
+    fp = _Py_fopen_obj(filename, "w+");
+
+    if (Py_IsTrue(print_raw)) {
+        flags = Py_PRINT_RAW;
+    }
+
+    if (PyObject_Print(object, fp, flags) < 0) {
+        return NULL;
+    }
+
+    fclose(fp);
+
+    Py_RETURN_NONE;
+}
+
+static PyObject *
+pyobject_print_null(PyObject *self, PyObject *args)
+{
+    PyObject *filename;
+    FILE *fp;
+
+    if (!PyArg_UnpackTuple(args, "call_pyobject_print", 1, 1, &filename)) {
+        return NULL;
+    }
+
+    fp = _Py_fopen_obj(filename, "w+");
+
+    if (PyObject_Print(NULL, fp, 0) < 0) {
+        return NULL;
+    }
+
+    fclose(fp);
+
+    Py_RETURN_NONE;
+}
+
+static PyObject *
+pyobject_print_noref_object(PyObject *self, PyObject *args)
+{
+    PyObject *test_string;
+    PyObject *filename;
+    FILE *fp;
+    char correct_string[100];
+
+    test_string = PyUnicode_FromString("Spam spam spam");
+
+    Py_DECREF(test_string);
+
+    snprintf(correct_string, 100, "<refcnt %zd at %p>", Py_REFCNT(test_string), (void *)test_string);
+
+    if (!PyArg_UnpackTuple(args, "call_pyobject_print", 1, 1, &filename)) {
+        return NULL;
+    }
+
+    fp = _Py_fopen_obj(filename, "w+");
+
+    if (PyObject_Print(test_string, fp, 0) < 0){
+        return NULL;
+    }
+
+    fclose(fp);
+
+    return PyUnicode_FromString(correct_string);
+}
+
+static PyObject *
+pyobject_print_os_error(PyObject *self, PyObject *args)
+{
+    PyObject *test_string;
+    PyObject *filename;
+    FILE *fp;
+
+    test_string = PyUnicode_FromString("Spam spam spam");
+
+    if (!PyArg_UnpackTuple(args, "call_pyobject_print", 1, 1, &filename)) {
+        return NULL;
+    }
+
+    // open file in read mode to induce OSError
+    fp = _Py_fopen_obj(filename, "r");
+
+    if (PyObject_Print(test_string, fp, 0) < 0) {
+        return NULL;
+    }
+
+    fclose(fp);
+
+    Py_RETURN_NONE;
+}
+
 static PyObject *
 raise_exception(PyObject *self, PyObject *args)
 {
@@ -5969,6 +6072,10 @@ static PyMethodDef TestMethods[] = {
     {"pyobject_repr_from_null", pyobject_repr_from_null, METH_NOARGS},
     {"pyobject_str_from_null",  pyobject_str_from_null, METH_NOARGS},
     {"pyobject_bytes_from_null", pyobject_bytes_from_null, METH_NOARGS},
+    {"call_pyobject_print", call_pyobject_print, METH_VARARGS},
+    {"pyobject_print_null", pyobject_print_null, METH_VARARGS},
+    {"pyobject_print_noref_object", pyobject_print_noref_object, METH_VARARGS},
+    {"pyobject_print_os_error", pyobject_print_os_error, METH_VARARGS},
     {"test_with_docstring",     test_with_docstring,             METH_NOARGS,
      PyDoc_STR("This is a pretty normal docstring.")},
     {"test_string_to_double",   test_string_to_double,           METH_NOARGS},