test and added box drawing characters

rich/cells.py

@@ -7,7 +7,9 @@
 from ._cell_widths import CELL_WIDTHS
 
 # Regex to match sequence of the most common character ranges
-_is_single_cell_widths = re.compile("^[\u0020-\u007f\u00a0\u02ff\u0370-\u0482]*$").match
+_is_single_cell_widths = re.compile(
+    "^[\u0020-\u007f\u00a0\u02ff\u0370-\u0482\u2500-\u25FF]*$"
+).match
 
 
 @lru_cache(4096)

tests/test_segment.py

@@ -1,9 +1,16 @@
+import string
 from io import StringIO
 
 import pytest
 
 from rich.cells import cell_len
-from rich.segment import ControlType, Segment, SegmentLines, Segments
+from rich.segment import (
+    ControlType,
+    Segment,
+    SegmentLines,
+    Segments,
+    _is_single_cell_widths,
+)
 from rich.style import Style
 
 
@@ -378,3 +385,22 @@ def test_align_bottom():
         [Segment("   ", Style())],
         [Segment("X")],
     ]
+
+
+def test_is_single_cell_widths() -> None:
+    # Check _is_single_cell_widths reports correctly
+    for character in string.printable:
+        if ord(character) >= 32:
+            assert _is_single_cell_widths(character)
+
+    BOX = "┌─┬┐│ ││├─┼┤│ ││├─┼┤├─┼┤│ ││└─┴┘"
+
+    for character in BOX:
+        print(repr(character))
+        assert _is_single_cell_widths(character)
+
+    for character in "💩":
+        assert not _is_single_cell_widths(character)
+
+    for character in "わさび":
+        assert not _is_single_cell_widths(character)