Add syntax highlighting to editor buffer display

src/mudlib/commands/edit.py

@@ -19,6 +19,7 @@ async def cmd_edit(player: Player, args: str) -> None:
     player.editor = Editor(
         save_callback=save_callback,
         content_type="text",
+        color_depth=player.color_depth,
     )
     player.mode_stack.append("editor")
     await player.send("Entering editor. Type :h for help.\r\n")

src/mudlib/editor.py

@@ -3,6 +3,8 @@
 from collections.abc import Awaitable, Callable
 from dataclasses import dataclass, field
 
+from mudlib.render.highlight import highlight
+
 
 @dataclass
 class EditorResponse:
@@ -26,6 +28,7 @@ class Editor:
     undo_stack: list[list[str]] = field(default_factory=list)
     save_callback: Callable[[str], Awaitable[None]] | None = None
     content_type: str = "text"  # hint for syntax highlighting later
+    color_depth: str = "16"  # "16", "256", or "truecolor"
     dirty: bool = False
 
     def __init__(
@@ -33,10 +36,12 @@ class Editor:
         initial_content: str = "",
         save_callback: Callable[[str], Awaitable[None]] | None = None,
         content_type: str = "text",
+        color_depth: str = "16",
     ):
         """Initialize editor with optional content."""
         self.save_callback = save_callback
         self.content_type = content_type
+        self.color_depth = color_depth
         self.cursor = 0
         self.undo_stack = []
         self.dirty = False
@@ -62,7 +67,20 @@ class Editor:
         if not self.buffer:
             return "(empty buffer)"
 
-        # Calculate padding for line numbers
+        # Use syntax highlighting if content_type is not "text"
+        if self.content_type != "text":
+            content = "\n".join(self.buffer)
+            highlighted = highlight(
+                content,
+                language=self.content_type,
+                color_depth=self.color_depth,
+                line_numbers=True,
+            )
+            # If highlight() returned the original (unknown language), fall through
+            if "\033[" in highlighted:
+                return highlighted
+
+        # Fall back to plain line-number formatting
         max_line_num = len(self.buffer)
         padding = len(str(max_line_num))
 
@@ -81,7 +99,22 @@ class Editor:
         start = max(0, line_num - 1 - context)
         end = min(len(self.buffer), line_num + context)
 
-        # Calculate padding for line numbers
+        # Use syntax highlighting if content_type is not "text"
+        if self.content_type != "text":
+            # Get the context window
+            context_lines = self.buffer[start:end]
+            content = "\n".join(context_lines)
+            highlighted = highlight(
+                content,
+                language=self.content_type,
+                color_depth=self.color_depth,
+                line_numbers=True,
+            )
+            # If highlight() returned highlighted content, use it
+            if "\033[" in highlighted:
+                return highlighted
+
+        # Fall back to plain line-number formatting
         max_line_num = end
         padding = len(str(max_line_num))
 

tests/test_editor.py

@@ -344,3 +344,77 @@ async def test_line_numbers_padded():
     # Find lines with numbers
     assert any(" 1  line 1" in line for line in lines)
     assert any("11  line 11" in line for line in lines)
+
+
+# Syntax highlighting tests
+
+
+@pytest.mark.asyncio
+async def test_view_buffer_with_python_includes_ansi():
+    """Viewing buffer with content_type=python includes ANSI codes."""
+    editor = Editor(
+        initial_content="def foo():\n    return 42",
+        content_type="python",
+        color_depth="16",
+    )
+    response = await editor.handle_input(":")
+    # Should contain ANSI escape codes from syntax highlighting
+    assert "\033[" in response.output
+    # Should contain the code
+    assert "def" in response.output
+    assert "foo" in response.output
+
+
+@pytest.mark.asyncio
+async def test_view_buffer_with_text_no_ansi():
+    """Viewing buffer with content_type=text does NOT include ANSI codes."""
+    editor = Editor(
+        initial_content="plain text line 1\nplain text line 2", content_type="text"
+    )
+    response = await editor.handle_input(":")
+    # Should NOT contain ANSI escape codes (plain line numbers)
+    assert "\033[" not in response.output
+    # Should contain plain line numbers
+    assert "1  plain text line 1" in response.output
+    assert "2  plain text line 2" in response.output
+
+
+@pytest.mark.asyncio
+async def test_view_specific_line_with_python_includes_ansi():
+    """Viewing a specific line with python content includes ANSI codes."""
+    content = "\n".join([f"def func{i}():\n    return {i}" for i in range(10)])
+    editor = Editor(
+        initial_content=content,
+        content_type="python",
+        color_depth="16",
+    )
+    response = await editor.handle_input(":5")
+    # Should contain ANSI escape codes from syntax highlighting
+    assert "\033[" in response.output
+    # Should contain code from the context window
+    assert "def" in response.output
+
+
+@pytest.mark.asyncio
+async def test_color_depth_passed_to_highlight():
+    """Color depth is passed through to highlight function."""
+    editor = Editor(
+        initial_content="x = 1\ny = 2",
+        content_type="python",
+        color_depth="256",
+    )
+    response = await editor.handle_input(":")
+    # Should contain ANSI codes (256-color formatter)
+    assert "\033[" in response.output
+    # Should contain the code
+    assert "x" in response.output
+    assert "y" in response.output
+
+
+@pytest.mark.asyncio
+async def test_empty_buffer_with_python_content_type():
+    """Empty buffer with content_type=python still works."""
+    editor = Editor(content_type="python", color_depth="16")
+    response = await editor.handle_input(":")
+    # Should show empty buffer message
+    assert "empty" in response.output.lower()