feat(rich): expose code_width and use the full terminal width by default

noirbizarre · noirbizarre · commit c8a303a83d3f · 2025-04-01T01:12:22.000+02:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -32,6 +32,11 @@ You can find our backwards-compatibility policy [here](https://github.com/hynek/
 - `structlog.processors.TimeStamper` now produces internally timezone-aware `datetime` objects.
   Default output hasn't changed, but you can now use `%z` in your *fmt* string.
   [#709](https://github.com/hynek/structlog/pull/709)
+- `structlog.dev.RichTracebackFormatter` now expose the upstream `code_width` parameter.
+  Default `width` is now `None` for full terminal width.
+  Full terminal width is now handled by `brich` itself, bringing support for reflow and `COLUMN` environment variable.
+  Using `-1` as width is now depreccated and automatically replaced by `None`.
+  [#717](https://github.com/hynek/structlog/pull/717)
 
 
 ### Fixed
diff --git a/src/structlog/dev.py b/src/structlog/dev.py
@@ -11,7 +11,6 @@
 
 from __future__ import annotations
 
-import shutil
 import sys
 import warnings
 
@@ -348,10 +347,15 @@ class RichTracebackFormatter:
 
     See :class:`rich.traceback.Traceback` for details on the arguments.
 
-    If a *width* of -1 is passed, the terminal width is used. If the width
+    If ``width`` is ``None``, the terminal width is used. If the width
     can't be determined, fall back to 80.
 
     .. versionadded:: 23.2.0
+
+    .. versionchanged:: 25.3.0
+        Default ``width`` is ``None`` to have full width and reflow support.
+        ``-1`` has width is deprecated, use ``None`` instead.
+        ``code_width`` is now exposed. ``word_wrap`` is enabled by default.
     """
 
     color_system: Literal[
@@ -360,9 +364,10 @@ class RichTracebackFormatter:
     show_locals: bool = True
     max_frames: int = 100
     theme: str | None = None
-    word_wrap: bool = False
+    word_wrap: bool = True
     extra_lines: int = 3
-    width: int = 100
+    width: int | None = None
+    code_width: int | None = 88
     indent_guides: bool = True
     locals_max_length: int = 10
     locals_max_string: int = 80
@@ -372,29 +377,37 @@ class RichTracebackFormatter:
 
     def __call__(self, sio: TextIO, exc_info: ExcInfo) -> None:
         if self.width == -1:
-            self.width, _ = shutil.get_terminal_size((80, 0))
+            warnings.warn(
+                "Use None to use the terminal width instead of -1.",
+                DeprecationWarning,
+                stacklevel=2,
+            )
+            self.width = None
 
         sio.write("\n")
 
-        Console(
+        console = Console(
             file=sio, color_system=self.color_system, width=self.width
-        ).print(
-            Traceback.from_exception(
-                *exc_info,
-                show_locals=self.show_locals,
-                max_frames=self.max_frames,
-                theme=self.theme,
-                word_wrap=self.word_wrap,
-                extra_lines=self.extra_lines,
-                width=self.width,
-                indent_guides=self.indent_guides,
-                locals_max_length=self.locals_max_length,
-                locals_max_string=self.locals_max_string,
-                locals_hide_dunder=self.locals_hide_dunder,
-                locals_hide_sunder=self.locals_hide_sunder,
-                suppress=self.suppress,
-            )
         )
+        tb = Traceback.from_exception(
+            *exc_info,
+            show_locals=self.show_locals,
+            max_frames=self.max_frames,
+            theme=self.theme,
+            word_wrap=self.word_wrap,
+            extra_lines=self.extra_lines,
+            width=self.width,
+            indent_guides=self.indent_guides,
+            locals_max_length=self.locals_max_length,
+            locals_max_string=self.locals_max_string,
+            locals_hide_dunder=self.locals_hide_dunder,
+            locals_hide_sunder=self.locals_hide_sunder,
+            suppress=self.suppress,
+        )
+        if hasattr(tb, "code_width"):
+            # `code_width` requires `rich>=13.8.0`
+            tb.code_width = self.code_width
+        console.print(tb)
 
 
 rich_traceback = RichTracebackFormatter()
diff --git a/tests/test_dev.py b/tests/test_dev.py
@@ -671,17 +671,46 @@ def test_does_not_blow_up(self, sio):
 
     def test_width_minus_one(self, sio):
         """
-        If width is -1, it's replaced by the terminal width on first use.
+        If width is -1, it raise a DeprecationWarning and replaced by None to let `rich` handle it.
         """
         rtf = dev.RichTracebackFormatter(width=-1)
 
-        with mock.patch("shutil.get_terminal_size", return_value=(42, 0)):
+        with pytest.deprecated_call():
             try:
                 0 / 0
             except ZeroDivisionError:
                 rtf(sio, sys.exc_info())
 
-        assert 42 == rtf.width
+        assert rtf.width is None
+
+    @pytest.mark.parametrize("code_width_support", [True, False])
+    def test_code_width_support(self, sio, code_width_support):
+        """
+        If rich does not support code_width, it should not fail
+        """
+        from rich.traceback import Trace
+
+        tb = mock.Mock(
+            spec=[
+                attr
+                for attr in dir(dev.Traceback(Trace([])))
+                if (code_width_support or attr != "code_width")
+            ]
+        )
+        tb.__rich_console__.return_value = "for Python 3.8 compatibility"
+
+        with mock.patch.object(
+            dev.Traceback, "from_exception", return_value=tb
+        ) as factory:
+            try:
+                0 / 0
+            except ZeroDivisionError:
+                dev.rich_traceback(sio, sys.exc_info())
+
+        assert "code_width" not in factory.call_args.kwargs
+
+        if code_width_support:
+            assert tb.code_width == 88
 
 
 @pytest.mark.skipif(
