Add softbreak renderer, migrate to hatchling (v0.3.0)

Convert soft breaks to hard breaks (backslash + newline) so paragraph
line breaks render as visible line breaks. Migrate build system from
flit_core to hatchling for proper editable install support.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: jdmonaco

mdformat_space_control/__init__.py

@@ -1,6 +1,6 @@
 """An mdformat plugin for space control: EditorConfig indentation, tight lists, frontmatter spacing, and wikilinks."""
 
-__version__ = "0.2.0"
+__version__ = "0.3.0"
 
 from .config import (
     get_current_file,

mdformat_space_control/plugin.py

@@ -222,6 +222,16 @@ def _render_wikilink(node: RenderTreeNode, context: RenderContext) -> str:
     return node.content
 
 
+def _render_softbreak(node: RenderTreeNode, context: RenderContext) -> str:
+    """Render soft breaks with terminal backslash.
+
+    Converts soft breaks (plain newlines within paragraphs) to hard breaks
+    (backslash + newline) to preserve visible line-break rendering and avoid
+    relying on trailing whitespace.
+    """
+    return "\\" + "\n"
+
+
 # A mapping from syntax tree node type to a function that renders it.
 # This can be used to overwrite renderer functions of existing syntax
 # or add support for new syntax.
@@ -230,6 +240,7 @@ def _render_wikilink(node: RenderTreeNode, context: RenderContext) -> str:
     "bullet_list": _render_bullet_list,
     "ordered_list": _render_ordered_list,
     "wikilink": _render_wikilink,
+    "softbreak": _render_softbreak,
 }
 
 

pyproject.toml

@@ -1,9 +1,11 @@
 [build-system]
-requires = ["flit_core >=3.2.0,<4"]
-build-backend = "flit_core.buildapi"
+requires = ["hatchling"]
+build-backend = "hatchling.build"
 
 [project]
 name = "mdformat_space_control"
+version = "0.3.0"
+description = "An mdformat plugin for space control: EditorConfig indentation, tight lists, frontmatter spacing, and wikilinks."
 authors = [
     { name = "Joseph Monaco", email = "joe@selfmotion.net" },
 ]
@@ -26,7 +28,6 @@ dependencies = [
     "mdformat>=0.7.0",
     "editorconfig>=0.12.0",
 ]
-dynamic = ["version", "description"]
 
 [project.optional-dependencies]
 test = [
@@ -42,8 +43,7 @@ Homepage = "https://github.com/jdmonaco/mdformat-space-control"
 [project.entry-points."mdformat.parser_extension"]
 space_control = "mdformat_space_control"
 
-[tool.flit.sdist]
-include = []
+[tool.hatch.build.targets.sdist]
 exclude = [".github/", "tests/"]
 
 [tool.pytest.ini_options]

tests/fixtures.md

@@ -219,7 +219,7 @@ checkbox with continuation
   continuation text
 - [x] Another task
 .
-- [ ] Task with
+- [ ] Task with\
   continuation text
 - [x] Another task
 .

tests/test_editorconfig.py

@@ -81,7 +81,7 @@ def test_bullet_list_continuation(self, temp_project):
 - Item 2
 """
         expected = """\
-- Item 1
+- Item 1\\
     with continuation
 - Item 2
 """

tests/test_integration.py

@@ -104,11 +104,11 @@ def test_tab_indent_ordered_list_continuation(self):
    continuation lines
 """
         expected = """\
-1. First item with
+1. First item with\\
 \tcontinuation line
 2. Second item
-3. Third item with
-\tmultiple
+3. Third item with\\
+\tmultiple\\
 \tcontinuation lines
 """
         with tempfile.TemporaryDirectory() as tmpdir:

tests/test_softbreak.py

@@ -0,0 +1,63 @@
+"""Tests for soft break to hard break conversion."""
+
+import mdformat
+
+
+class TestSoftBreakConversion:
+    """Tests for converting soft breaks to hard breaks (backslash + newline)."""
+
+    def test_soft_break_gets_backslash(self):
+        """Plain newline within a paragraph should become backslash + newline."""
+        input_text = "Line one\nLine two.\n"
+        expected = "Line one\\\nLine two.\n"
+        result = mdformat.text(input_text, extensions={"space_control"})
+        assert result == expected
+
+    def test_multiple_soft_breaks(self):
+        """Multiple soft breaks in a paragraph should all get backslashes."""
+        input_text = "Line one\nLine two\nLine three.\n"
+        expected = "Line one\\\nLine two\\\nLine three.\n"
+        result = mdformat.text(input_text, extensions={"space_control"})
+        assert result == expected
+
+    def test_bold_label_lines(self):
+        """AI-generated bold label lines should preserve line breaks."""
+        input_text = "**Date**: January 30\n**Time**: 2:00 PM\n**Location**: Room 101\n"
+        expected = "**Date**: January 30\\\n**Time**: 2:00 PM\\\n**Location**: Room 101\n"
+        result = mdformat.text(input_text, extensions={"space_control"})
+        assert result == expected
+
+    def test_paragraph_break_unaffected(self):
+        """Double newline (paragraph break) should not be affected."""
+        input_text = "First paragraph.\n\nSecond paragraph.\n"
+        expected = "First paragraph.\n\nSecond paragraph.\n"
+        result = mdformat.text(input_text, extensions={"space_control"})
+        assert result == expected
+
+    def test_existing_hard_break_preserved(self):
+        """Lines already ending with backslash should remain correct."""
+        input_text = "Line one\\\nLine two.\n"
+        expected = "Line one\\\nLine two.\n"
+        result = mdformat.text(input_text, extensions={"space_control"})
+        assert result == expected
+
+    def test_code_block_newlines_unaffected(self):
+        """Newlines inside fenced code blocks should not get backslashes."""
+        input_text = "```\nline one\nline two\n```\n"
+        expected = "```\nline one\nline two\n```\n"
+        result = mdformat.text(input_text, extensions={"space_control"})
+        assert result == expected
+
+    def test_single_line_paragraph_unaffected(self):
+        """A single-line paragraph should not be modified."""
+        input_text = "Just one line.\n"
+        expected = "Just one line.\n"
+        result = mdformat.text(input_text, extensions={"space_control"})
+        assert result == expected
+
+    def test_soft_break_in_list_item(self):
+        """Soft breaks within list items should get backslashes."""
+        input_text = "- Line one\n  Line two\n"
+        expected = "- Line one\\\n  Line two\n"
+        result = mdformat.text(input_text, extensions={"space_control"})
+        assert result == expected