Tabs and Indents visitor (#104)

* Add test cases for tabs and indents visitor

* Add extra test cases for autoformat

* More tests

* Add helper methods

* Add helper method to cursor

* Add WIP version of visitor

* Add extended test cases

* WIP comment support and further extension

* Add Tree Printer

* Fixes

* Add fixed and some extra tests

* Add some trailing comma handling in collection literals

* Add extra test and some support code for METHOD_SELECT_SUFFIX

* Reorder

* Add extra test cases for comments and mark some test with xfail

* Polish `TabsAndIndentsVisitor`

---------

Co-authored-by: Knut Wannheden <knut@moderne.io>

Author: nielsdebruin

rewrite/rewrite/java/support_types.py

@@ -106,8 +106,8 @@ def with_comments(self, comments: List[Comment]) -> Space:
     _whitespace: Optional[str]
 
     @property
-    def whitespace(self) -> Optional[str]:
-        return self._whitespace
+    def whitespace(self) -> str:
+        return self._whitespace if self._whitespace is not None else ""
 
     def with_whitespace(self, whitespace: Optional[str]) -> Space:
         return self if whitespace is self._whitespace else replace(self, _whitespace=whitespace)
@@ -127,6 +127,36 @@ def format_first_prefix(cls, trees: List[J2], prefix: Space) -> List[J2]:
             return formatted_trees
         return trees
 
+    @property
+    def indent(self) -> str:
+        """
+        The indentation after the last newline of either the last comment's suffix
+        or the global whitespace if no comments exist.
+        """
+        return self._get_whitespace_indent(self.last_whitespace)
+
+    @property
+    def last_whitespace(self) -> str:
+        """
+        The raw suffix from the last comment if it exists, otherwise the global
+        whitespace (or empty string if whitespace is None).
+        """
+        if self._comments:
+            return self._comments[-1].suffix
+        return self._whitespace if self._whitespace is not None else ""
+
+    @staticmethod
+    def _get_whitespace_indent(whitespace: Optional[str]) -> str:
+        """
+        A helper method that extracts everything after the last newline character
+        in `whitespace`. If no newline is present, returns `whitespace` as-is.
+        If the last newline is at the end, returns an empty string.
+        """
+        if not whitespace:
+            return ""
+        last_newline = whitespace.rfind('\n')
+        return whitespace if last_newline == -1 else whitespace[last_newline + 1:]
+
     EMPTY: ClassVar[Space]
     SINGLE_SPACE: ClassVar[Space]
 

rewrite/rewrite/python/format/auto_format.py

@@ -6,7 +6,8 @@
 from .normalize_tabs_or_spaces import NormalizeTabsOrSpacesVisitor
 from .remove_trailing_whitespace_visitor import RemoveTrailingWhitespaceVisitor
 from .spaces_visitor import SpacesVisitor
-from .. import TabsAndIndentsStyle, GeneralFormatStyle
+from .tabs_and_indents_visitor import TabsAndIndentsVisitor
+from .. import TabsAndIndentsStyle, GeneralFormatStyle, WrappingAndBracesStyle
 from ..style import BlankLinesStyle, SpacesStyle, IntelliJ
 from ..visitor import PythonVisitor
 from ... import Recipe, Tree, Cursor
@@ -28,13 +29,22 @@ def visit(self, tree: Optional[Tree], p: P, parent: Optional[Cursor] = None) ->
         cu = tree if isinstance(tree, JavaSourceFile) else self._cursor.first_enclosing_or_throw(JavaSourceFile)
 
         tree = NormalizeFormatVisitor(self._stop_after).visit(tree, p, self._cursor.fork())
+
         tree = BlankLinesVisitor(cu.get_style(BlankLinesStyle) or IntelliJ.blank_lines(), self._stop_after).visit(tree, p, self._cursor.fork())
+
         tree = SpacesVisitor(cu.get_style(SpacesStyle) or IntelliJ.spaces(), self._stop_after).visit(tree, p, self._cursor.fork())
+
         tree = NormalizeTabsOrSpacesVisitor(
             cu.get_style(TabsAndIndentsStyle) or IntelliJ.tabs_and_indents(),
             self._stop_after
         ).visit(tree, p, self._cursor.fork())
+
+        tree = TabsAndIndentsVisitor(cu.get_style(TabsAndIndentsStyle) or IntelliJ.tabs_and_indents(),
+                                          self._stop_after).visit(tree, p, self._cursor.fork())
+
         tree = NormalizeLineBreaksVisitor(cu.get_style(GeneralFormatStyle) or GeneralFormatStyle(False),
                                           self._stop_after).visit(tree, p, self._cursor.fork())
+
         tree = RemoveTrailingWhitespaceVisitor(self._stop_after).visit(tree, self._cursor.fork())
+
         return tree