add tests

python · encukou · Dec 4, 2024 · Aug 26, 2024 · Aug 27, 2024 · Aug 27, 2024
commit 60ab0bb67f1b0469a2b76f9b25fc6f5ae2e89efb
diff --git a/Lib/test/test_capi/test_exceptions.py b/Lib/test/test_capi/test_exceptions.py
@@ -415,6 +415,52 @@ def test_err_formatunraisable(self):
         # CRASHES formatunraisable(NULL, NULL)
 
 
+class TestUnicodeError(unittest.TestCase):
+
+    def test_unicode_encode_error_get_start(self):
+        test_func = _testcapi.unicode_encode_get_start
+        self._test_unicode_error_get_start('x', UnicodeEncodeError, test_func)
+
+    def test_unicode_decode_error_get_start(self):
+        test_func = _testcapi.unicode_decode_get_start
+        self._test_unicode_error_get_start(b'x', UnicodeDecodeError, test_func)
+
+    def _test_unicode_error_get_start(self, literal, exc_type, test_func):
+        for obj_len, py_start, c_start in [
+            # normal cases
+            (5, 0, 0),
+            (5, 1, 1),
+            (5, 2, 2),
+            # negative start is clamped to 0
+            (0, -1, 0),
+            (2, -1, 0),
+            # out of range start is clamped to max(0, obj_len - 1)
+            (0, 0, 0),
+            (0, 1, 0),
+            (0, 10, 0),
+            (2, 0, 0),
+            (5, 5, 4),
+            (5, 10, 4),
+        ]:
+            c_start_computed = py_start
+            if c_start_computed < 0:
+                c_start_computed = 0
+            if c_start_computed >= obj_len:
+                if obj_len == 0:
+                    c_start_computed = 0
+                else:
+                    c_start_computed = obj_len - 1
+
+            s = literal * obj_len
+            py_end = py_start + 1
+
+            with self.subTest(s, exc_type=exc_type, py_start=py_start, c_start=c_start):
+                self.assertEqual(c_start, c_start_computed)
+                exc = exc_type('utf-8', s, py_start, py_end, 'reason')
+                c_start_actual = test_func(exc)
+                self.assertEqual(c_start_actual, c_start)
+
+
 class Test_PyUnstable_Exc_PrepReraiseStar(ExceptionIsLikeMixin, unittest.TestCase):
 
     def setUp(self):

diff --git a/Modules/_testcapi/exceptions.c b/Modules/_testcapi/exceptions.c
@@ -359,6 +359,27 @@ _testcapi_unstable_exc_prep_reraise_star_impl(PyObject *module,
     return PyUnstable_Exc_PrepReraiseStar(orig, excs);
 }
 
+/* Test PyUnicodeEncodeError_GetStart */
+static PyObject *
+unicode_encode_get_start(PyObject *Py_UNUSED(module), PyObject *arg)
+{
+    Py_ssize_t start;
+    if (PyUnicodeEncodeError_GetStart(arg, &start) < 0) {
+        return NULL;
+    }
+    RETURN_SIZE(start);
+}
+
+/* Test PyUnicodeDecodeError_GetStart */
+static PyObject *
+unicode_decode_get_start(PyObject *Py_UNUSED(module), PyObject *arg)
+{
+    Py_ssize_t start;
+    if (PyUnicodeDecodeError_GetStart(arg, &start) < 0) {
+        return NULL;
+    }
+    RETURN_SIZE(start);
+}
 
 /*
  * Define the PyRecurdingInfinitelyError_Type
@@ -403,6 +424,8 @@ static PyMethodDef test_methods[] = {
     _TESTCAPI_SET_EXCEPTION_METHODDEF
     _TESTCAPI_TRACEBACK_PRINT_METHODDEF
     _TESTCAPI_UNSTABLE_EXC_PREP_RERAISE_STAR_METHODDEF
+    {"unicode_encode_get_start", unicode_encode_get_start,       METH_O},
+    {"unicode_decode_get_start", unicode_decode_get_start,       METH_O},
     {NULL},
 };