1 files changed, 90 insertions, 0 deletions
diff --git a/tests/test_util/test_util_console.py b/tests/test_util/test_util_console.py
new file mode 100644
index 0000000..b617a33
--- /dev/null
+++ b/tests/test_util/test_util_console.py
@@ -0,0 +1,90 @@
+from __future__ import annotations
+
+import itertools
+import operator
+from typing import TYPE_CHECKING
+
+import pytest
+
+from sphinx.util.console import blue, reset, strip_colors, strip_escape_sequences
+
+if TYPE_CHECKING:
+    from collections.abc import Callable, Sequence
+    from typing import Final, TypeVar
+
+    _T = TypeVar('_T')
+
+CURSOR_UP: Final[str] = '\x1b[2A'  # ignored ANSI code
+ERASE_LINE: Final[str] = '\x1b[2K'  # supported ANSI code
+TEXT: Final[str] = '\x07 Hello world!'
+
+
+@pytest.mark.parametrize(
+    ('strip_function', 'ansi_base_blocks', 'text_base_blocks'),
+    [
+        (
+            strip_colors,
+            # double ERASE_LINE so that the tested strings may have 2 of them
+            [TEXT, blue(TEXT), reset(TEXT), ERASE_LINE, ERASE_LINE, CURSOR_UP],
+            # :func:`strip_colors` removes color codes but keeps ERASE_LINE and CURSOR_UP
+            [TEXT, TEXT, TEXT, ERASE_LINE, ERASE_LINE, CURSOR_UP],
+        ),
+        (
+            strip_escape_sequences,
+            # double ERASE_LINE so that the tested strings may have 2 of them
+            [TEXT, blue(TEXT), reset(TEXT), ERASE_LINE, ERASE_LINE, CURSOR_UP],
+            # :func:`strip_escape_sequences` strips ANSI codes known by Sphinx
+            [TEXT, TEXT, TEXT, '', '', CURSOR_UP],
+        ),
+    ],
+    ids=[strip_colors.__name__, strip_escape_sequences.__name__],
+)
+def test_strip_ansi(
+    strip_function: Callable[[str], str],
+    ansi_base_blocks: Sequence[str],
+    text_base_blocks: Sequence[str],
+) -> None:
+    assert callable(strip_function)
+    assert len(text_base_blocks) == len(ansi_base_blocks)
+    N = len(ansi_base_blocks)
+
+    def next_ansi_blocks(choices: Sequence[str], n: int) -> Sequence[str]:
+        # Get a list of *n* words from a cyclic sequence of *choices*.
+        #
+        # For instance ``next_ansi_blocks(['a', 'b'], 3) == ['a', 'b', 'a']``.
+        stream = itertools.cycle(choices)
+        return list(map(operator.itemgetter(0), zip(stream, range(n))))
+
+    # generate all permutations of length N
+    for sigma in itertools.permutations(range(N), N):
+        # apply the permutation on the blocks with ANSI codes
+        ansi_blocks = list(map(ansi_base_blocks.__getitem__, sigma))
+        # apply the permutation on the blocks with stripped codes
+        text_blocks = list(map(text_base_blocks.__getitem__, sigma))
+
+        for glue, n in itertools.product(['.', '\n', '\r\n'], range(4 * N)):
+            ansi_strings = next_ansi_blocks(ansi_blocks, n)
+            text_strings = next_ansi_blocks(text_blocks, n)
+            assert len(ansi_strings) == len(text_strings) == n
+
+            ansi_string = glue.join(ansi_strings)
+            text_string = glue.join(text_strings)
+            assert strip_function(ansi_string) == text_string
+
+
+def test_strip_ansi_short_forms():
+    # In Sphinx, we always "normalize" the color codes so that they
+    # match "\x1b\[(\d\d;){0,2}(\d\d)m" but it might happen that
+    # some messages use '\x1b[0m' instead of ``reset(s)``, so we
+    # test whether this alternative form is supported or not.
+
+    for strip_function in [strip_colors, strip_escape_sequences]:
+        # \x1b[m and \x1b[0m are equivalent to \x1b[00m
+        assert strip_function('\x1b[m') == ''
+        assert strip_function('\x1b[0m') == ''
+
+        # \x1b[1m is equivalent to \x1b[01m
+        assert strip_function('\x1b[1mbold\x1b[0m') == 'bold'
+
+    # \x1b[K is equivalent to \x1b[0K
+    assert strip_escape_sequences('\x1b[K') == ''