tests: backslash+bracket regression guards; xfail raw backslash-before-[ bug (#2993)

tests/test_markup_backslash_escape.py

@@ -0,0 +1,48 @@
+import pytest
+from rich.text import Text
+from rich.markup import escape
+
+def _roundtrip(s: str) -> str:
+    """escape() then parse as markup; return plain text for comparison."""
+    escaped = escape(s)
+    return Text.from_markup(escaped).plain
+
+@pytest.mark.parametrize(
+    "raw",
+    [
+        r"\[b]hello\[/b]",
+        r"C:\[bin]\tools",
+        r"C:\\[bin]\\tools",
+        r"\[color(123,45,6)]x\[/color]",
+    ],
+)
+def test_from_markup_handles_backslash_escaped_brackets(raw: str) -> None:
+    """Backslash-escaped brackets must be treated as literals (no mismatched tags)."""
+    text = Text.from_markup(raw)  # must not raise
+    assert text.plain.replace("\u200b", "")  # force render; content exists
+
+def test_escape_then_from_markup_roundtrips_common_windows_path() -> None:
+    s = r"C:\Users\[name]\AppData\Local"
+    assert _roundtrip(s) == s
+
+@pytest.mark.parametrize(
+    ("s", "expected"),
+    [
+        (r"\[b]x\[/b]", "[b]x[/b]"),
+        # NOTE: the raw backslash-before-[ case is covered by an xfail test below
+    ],
+)
+def test_backslash_literal_output(s: str, expected: str) -> None:
+    """Already-escaped brackets render literally as plain text."""
+    plain = Text.from_markup(s).plain
+    assert plain.replace("\u200b", "") == expected
+
+@pytest.mark.xfail(reason="Loses backslash before '['; see #2993", strict=False)
+def test_windows_path_with_brackets_should_render_literally() -> None:
+    """
+    Document current bug: a backslash immediately before '[' is swallowed.
+    Desired behavior: render literally.
+    """
+    s = r"C:\[tmp]\file.txt"
+    plain = Text.from_markup(s).plain
+    assert plain.replace("\u200b", "") == s