Add support for normalizing linebreak in trailing comma (#103)

Author: nielsdebruin

rewrite/rewrite/python/format/normalize_line_breaks_visitor.py

@@ -1,9 +1,9 @@
 from __future__ import annotations
 
-from typing import Optional, TypeVar, Union
+from typing import Optional, TypeVar, Union, cast
 
-from rewrite import Tree, P, Cursor, list_map
-from rewrite.java import J, Space, Comment, TextComment
+from rewrite import Tree, P, Cursor, list_map, Marker
+from rewrite.java import J, Space, Comment, TextComment, TrailingComma
 from rewrite.python import PythonVisitor, PySpace, GeneralFormatStyle, PyComment
 from rewrite.visitor import T
 
@@ -43,6 +43,12 @@ def post_visit(self, tree: T, _: object) -> Optional[T]:
     def visit(self, tree: Optional[Tree], p: P, parent: Optional[Cursor] = None) -> Optional[T]:
         return tree if self._stop else super().visit(tree, p, parent)
 
+    def visit_marker(self, marker: Marker, p: P) -> Marker:
+        m = cast(Marker, super().visit_marker(marker, p))
+        if isinstance(m, TrailingComma):
+            return m.with_suffix(self.visit_space(m.suffix, None, p))
+        return m
+
 
 STR = TypeVar('STR', bound=Optional[str])
 

rewrite/tests/python/all/format/normalize_line_breaks_visitor_test.py

@@ -14,6 +14,10 @@ def setUp(self):
             "    # some comment\r\n"
             "    def test(self):\r\n"
             "        print()\r\n"
+            "        a = [\r\n"
+            "              1,\r\n"
+            "              2,\r\n"
+            "            ]\r\n"
             "\r\n"
         )
         # language=python
@@ -22,6 +26,10 @@ def setUp(self):
             "    # some comment\n"
             "    def test(self):\n"
             "        print()\n"
+            "        a = [\n"
+            "              1,\n"
+            "              2,\n"
+            "            ]\n"
             "\n"
         )