Add more tests and fix some edge cases

Author: pablogsal

Lib/test/test_exceptions.py

@@ -8,6 +8,7 @@
 import pickle
 import weakref
 import errno
+from textwrap import dedent
 
 from test.support import (captured_stderr, check_impl_detail,
                           cpython_only, gc_collect,
@@ -1833,6 +1834,130 @@ def test_copy_pickle(self):
                 self.assertEqual(exc.name, orig.name)
                 self.assertEqual(exc.path, orig.path)
 
+class SyntaxErrorTests(unittest.TestCase):
+    def test_range_of_offsets(self):
+        cases = [
+            # Basic range from 2->7
+            (("bad.py", 1, 2, "abcdefg", 1, 7),
+             dedent(
+             """
+               File "bad.py", line 1
+                 abcdefg
+                  ^^^^^
+             SyntaxError: bad bad
+             """)),
+            # end_offset = start_offset + 1
+            (("bad.py", 1, 2, "abcdefg", 1, 3),
+             dedent(
+             """
+               File "bad.py", line 1
+                 abcdefg
+                  ^
+             SyntaxError: bad bad
+             """)),
+            # Negative end offset
+            (("bad.py", 1, 2, "abcdefg", 1, -2),
+             dedent(
+             """
+               File "bad.py", line 1
+                 abcdefg
+                  ^
+             SyntaxError: bad bad
+             """)),
+            # end offset before starting offset
+            (("bad.py", 1, 4, "abcdefg", 1, 2),
+             dedent(
+             """
+               File "bad.py", line 1
+                 abcdefg
+                    ^
+             SyntaxError: bad bad
+             """)),
+            # Both offsets negative
+            (("bad.py", 1, -4, "abcdefg", 1, -2),
+             dedent(
+             """
+               File "bad.py", line 1
+                 abcdefg
+             SyntaxError: bad bad
+             """)),
+            # Both offsets negative and the end more negatibe
+            (("bad.py", 1, -4, "abcdefg", 1, -5),
+             dedent(
+             """
+               File "bad.py", line 1
+                 abcdefg
+             SyntaxError: bad bad
+             """)),
+            # Both offsets 0
+            (("bad.py", 1, 0, "abcdefg", 1, 0),
+             dedent(
+             """
+               File "bad.py", line 1
+                 abcdefg
+             SyntaxError: bad bad
+             """)),
+            # Start offset 0 and end offset not 0
+            (("bad.py", 1, 0, "abcdefg", 1, 5),
+             dedent(
+             """
+               File "bad.py", line 1
+                 abcdefg
+             SyntaxError: bad bad
+             """)),
+            # End offset pass the source lenght
+            (("bad.py", 1, 2, "abcdefg", 1, 100),
+             dedent(
+             """
+               File "bad.py", line 1
+                 abcdefg
+                  ^^^^^^
+             SyntaxError: bad bad
+             """)),
+        ]
+        for args, expected in cases:
+            with self.subTest(args=args):
+                try:
+                    raise SyntaxError("bad bad", args)
+                except SyntaxError as exc:
+                    with support.captured_stderr() as err:
+                        sys.__excepthook__(*sys.exc_info())
+                    the_exception = exc
+
+    def test_attributes_new_constructor(self):
+        args = ("bad.py", 1, 2, "abcdefg", 1, 100)
+        the_exception = SyntaxError("bad bad", args)
+        filename, lineno, offset, error, end_lineno, end_offset = args
+        self.assertEqual(filename, the_exception.filename)
+        self.assertEqual(lineno, the_exception.lineno)
+        self.assertEqual(end_lineno, the_exception.end_lineno)
+        self.assertEqual(offset, the_exception.offset)
+        self.assertEqual(end_offset, the_exception.end_offset)
+        self.assertEqual(error, the_exception.text)
+        self.assertEqual("bad bad", the_exception.msg)
+
+    def test_attributes_old_constructor(self):
+        args = ("bad.py", 1, 2, "abcdefg")
+        the_exception = SyntaxError("bad bad", args)
+        filename, lineno, offset, error = args
+        self.assertEqual(filename, the_exception.filename)
+        self.assertEqual(lineno, the_exception.lineno)
+        self.assertEqual(None, the_exception.end_lineno)
+        self.assertEqual(offset, the_exception.offset)
+        self.assertEqual(None, the_exception.end_offset)
+        self.assertEqual(error, the_exception.text)
+        self.assertEqual("bad bad", the_exception.msg)
+
+    def test_incorrect_constructor(self):
+        args = ("bad.py", 1, 2)
+        self.assertRaises(TypeError, SyntaxError, "bad bad", args)
+
+        args = ("bad.py", 1, 2, 4, 5, 6, 7)
+        self.assertRaises(TypeError, SyntaxError, "bad bad", args)
+
+        args = ("bad.py", 1, 2, "abcdefg", 1)
+        self.assertRaises(TypeError, SyntaxError, "bad bad", args)
+
 
 class PEP626Tests(unittest.TestCase):
 

Objects/exceptions.c

@@ -1494,8 +1494,9 @@ SyntaxError_init(PySyntaxErrorObject *self, PyObject *args, PyObject *kwds)
     if (lenargs == 2) {
         info = PyTuple_GET_ITEM(args, 1);
         info = PySequence_Tuple(info);
-        if (!info)
+        if (!info) {
             return -1;
+        }
 
         self->end_lineno = NULL;
         self->end_offset = NULL;
@@ -1505,7 +1506,7 @@ SyntaxError_init(PySyntaxErrorObject *self, PyObject *args, PyObject *kwds)
                               &self->end_lineno, &self->end_offset)) {
             Py_DECREF(info);
             return -1;
-        }
+        } 
 
         Py_INCREF(self->filename);
         Py_INCREF(self->lineno);
@@ -1515,6 +1516,11 @@ SyntaxError_init(PySyntaxErrorObject *self, PyObject *args, PyObject *kwds)
         Py_XINCREF(self->end_offset);
         Py_DECREF(info);
 
+        if (self->end_lineno != NULL && self->end_offset == NULL) {
+            PyErr_SetString(PyExc_TypeError, "end_offset must be provided when end_lineno is provided");
+            return -1;
+        }
+
         /*
          * Issue #21669: Custom error for 'print' & 'exec' as statements
          *

Python/pythonrun.c

@@ -628,7 +628,7 @@ parse_syntax_error(PyObject *err, PyObject **message, PyObject **filename,
 static void
 print_error_text(PyObject *f, Py_ssize_t offset, Py_ssize_t end_offset, PyObject *text_obj)
 {
-    size_t caret_repetitions = end_offset > 0 && end_offset != offset ? end_offset - offset : 1;
+    size_t caret_repetitions = (end_offset > 0 && end_offset > offset) ? end_offset - offset : 1;
     /* Convert text to a char pointer; return if error */
     const char *text = PyUnicode_AsUTF8(text_obj);
     if (text == NULL)
@@ -945,7 +945,7 @@ print_exception(PyObject *f, PyObject *value)
                 // Limit the ammount of '^' that we can display to
                 // the size of the text in the source line.
                 if (error_line != NULL && end_offset > line_size + 1) {
-                    end_offset = line_size;
+                    end_offset = line_size + 1;
                 }
                 print_error_text(f, offset, end_offset, text);
                 Py_DECREF(text);