fix(git): tolerate noisy git rev-parse output in is_git_project

commitizen/git.py

@@ -1,8 +1,10 @@
 from __future__ import annotations
 
 import os
+import re
 from enum import Enum
 from functools import lru_cache
+from logging import getLogger
 from pathlib import Path
 from tempfile import NamedTemporaryFile
 from typing import TYPE_CHECKING
@@ -14,6 +16,15 @@
     from collections.abc import Sequence
 
 
+logger = getLogger("commitizen")
+
+
+# Match common ANSI control sequences (CSI ``\x1b[...letter`` and SGR resets)
+# so wrappers that wrap git's output in colour codes don't break the
+# ``true`` / ``false`` parse in :func:`is_git_project` (#1497).
+_ANSI_ESCAPE = re.compile(r"\x1b\[[0-?]*[ -/]*[@-~]")
+
+
 class EOLType(Enum):
     """The EOL type from `git config core.eol`."""
 
@@ -312,8 +323,32 @@ def is_staging_clean() -> bool:
 
 
 def is_git_project() -> bool:
+    """Check whether we're inside a git work tree.
+
+    Trusts ``git rev-parse``'s exit code as the primary signal: if the command
+    exits non-zero, we're not in a git context. The textual output (``true`` /
+    ``false``) is then used to distinguish a work tree from a bare-repo
+    interior. ANSI colour codes (which some shell wrappers inject) are
+    stripped before the exact-match check, so legitimate-looking strings like
+    ``untrue`` / ``nottrue`` are still rejected (#1497).
+    """
     c = cmd.run(["git", "rev-parse", "--is-inside-work-tree"])
-    return c.out.strip() == "true"
+    if c.return_code != 0:
+        logger.debug(
+            "is_git_project: git rev-parse failed (rc=%d) out=%r err=%r",
+            c.return_code,
+            c.out,
+            c.err,
+        )
+        return False
+    cleaned = _ANSI_ESCAPE.sub("", c.out).strip().lower()
+    inside_work_tree = cleaned == "true"
+    if not inside_work_tree:
+        logger.debug(
+            "is_git_project: git rev-parse said not a work tree: out=%r",
+            c.out,
+        )
+    return inside_work_tree
 
 
 def get_core_editor() -> str | None:

tests/test_git.py

@@ -309,6 +309,49 @@ def test_is_staging_clean_when_updating_file():
     assert git.is_staging_clean() is False
 
 
+@pytest.mark.usefixtures("tmp_commitizen_project")
+def test_is_git_project_inside_work_tree():
+    assert git.is_git_project() is True
+
+
+def test_is_git_project_outside_repo(tmp_path: Path, monkeypatch: pytest.MonkeyPatch):
+    """When ``git rev-parse`` exits non-zero (no repo above us),
+    ``is_git_project`` returns ``False``."""
+    monkeypatch.chdir(tmp_path)
+    assert git.is_git_project() is False
+
+
+def test_is_git_project_accepts_loose_true_output(mocker: MockFixture):
+    """Regression test for #1497: shell wrappers that prepend ANSI colour
+    codes or trailing whitespace to ``git rev-parse``'s output must not flip
+    ``is_git_project`` to ``False``."""
+    fake = cmd.Command("\x1b[0mtrue\r\n", "", b"", b"", 0)
+    mocker.patch("commitizen.cmd.run", return_value=fake)
+    assert git.is_git_project() is True
+
+
+def test_is_git_project_returns_false_for_bare_repo(mocker: MockFixture):
+    """``git rev-parse`` exits 0 but says ``false`` when run from inside the
+    ``.git`` directory of a bare repo. ``is_git_project`` is meant to gate
+    work-tree commands, so this case should still return ``False``."""
+    fake = cmd.Command("false\n", "", b"", b"", 0)
+    mocker.patch("commitizen.cmd.run", return_value=fake)
+    assert git.is_git_project() is False
+
+
+@pytest.mark.parametrize("noise", ["untrue", "nottrue", "test true false"])
+def test_is_git_project_rejects_strings_containing_true_substring(
+    mocker: MockFixture, noise: str
+):
+    """The ``true`` token must be matched as a whole word at the end of the
+    output, not just any string ending in ``true``. Even though git itself
+    will never produce these strings, a defensive matcher shouldn't accept
+    them either."""
+    fake = cmd.Command(f"{noise}\n", "", b"", b"", 0)
+    mocker.patch("commitizen.cmd.run", return_value=fake)
+    assert git.is_git_project() is False
+
+
 @pytest.mark.usefixtures("tmp_commitizen_project")
 def test_get_eol_for_open():
     assert git.EOLType.for_open() == os.linesep