Files
hermes-agent/tests/tools/test_find_shell.py
kshitijk4poor 99e1c16868 test(tools): pin the Git Bash probe's detached stdin in the existing probe test
The new standalone test file duplicated TestGitBashExternalProgramProbe's
harness; one assertion on the recorded kwargs covers the #78820 contract.
The sibling ASLR-probe assertion is dropped (unchanged code, already green
on main). Comment trimmed to the WHY.
2026-09-08 02:26:39 +05:30

219 lines
9.1 KiB
Python

"""Tests for _find_shell — user-login-shell preference on POSIX.
Regression tests for #42203: on macOS, ``_find_shell`` used to return
``/bin/bash`` (bash 3.2) which silently swallowed background commands
when ``~/.bash_profile`` contained ``exec /bin/zsh -l``.
"""
import os
import platform
import subprocess
from unittest.mock import patch
import pytest
from tools.environments.local import _find_bash, _find_shell
class TestFindShellPrefersUserShell:
"""_find_shell should prefer $SHELL over bash on POSIX."""
@pytest.mark.platforms("linux")
def test_returns_shell_env_when_set_and_exists(self, tmp_path):
"""When $SHELL points to an existing allowlisted executable, _find_shell returns it."""
fake_zsh = tmp_path / "zsh"
fake_zsh.touch()
fake_zsh.chmod(0o755)
with patch.dict(os.environ, {"SHELL": str(fake_zsh)}):
assert _find_shell() == str(fake_zsh)
def test_falls_back_when_shell_not_executable(self, tmp_path):
"""$SHELL exists but lacks the execute bit -> fall back to _find_bash
(returning it would fail at spawn time)."""
fake = tmp_path / "zsh"
fake.touch()
fake.chmod(0o644) # not executable
with patch.dict(os.environ, {"SHELL": str(fake)}):
assert _find_shell() == _find_bash()
def test_falls_back_for_incompatible_shell_fish(self, tmp_path):
"""#42203 regression: $SHELL=fish must NOT be returned — spawn_local's
`-lic` / `set +m` syntax breaks fish, which would trade the bash-3.2
swallow for a parse error on every background command. Fall back to bash."""
fake_fish = tmp_path / "fish"
fake_fish.touch()
fake_fish.chmod(0o755)
with patch.dict(os.environ, {"SHELL": str(fake_fish)}):
assert _find_shell() == _find_bash()
@pytest.mark.platforms("linux")
def test_honours_allowlisted_bash_and_dash(self, tmp_path):
"""Every allowlisted POSIX-sh-family shell is honoured."""
for name in ("bash", "dash", "sh", "ksh"):
fake = tmp_path / name
fake.touch()
fake.chmod(0o755)
with patch.dict(os.environ, {"SHELL": str(fake)}):
assert _find_shell() == str(fake), name
def test_falls_back_to_find_bash_when_shell_empty(self):
"""When $SHELL is empty string, _find_shell delegates."""
with patch.dict(os.environ, {"SHELL": ""}):
assert _find_shell() == _find_bash()
class TestFindShellWindowsBehavior:
"""On Windows, _find_shell always delegates to _find_bash."""
@pytest.mark.platforms("windows")
def test_windows_ignores_shell_env(self):
"""On Windows, $SHELL is ignored — _find_shell delegates to _find_bash.
Windows-only: faking ``_IS_WINDOWS`` selected the branch but left
``_find_bash`` resolving a POSIX bash, so the equality proved nothing
about Git-Bash resolution on the real host.
"""
# Even if SHELL is set, it should be ignored on Windows
with patch.dict(os.environ, {"SHELL": "/usr/bin/zsh"}):
result = _find_shell()
assert result == _find_bash()
class TestFindShellReturnsString:
"""_find_shell must return a string, never None."""
def test_returns_string(self):
"""_find_shell always returns a non-empty string on any platform."""
result = _find_shell()
assert isinstance(result, str)
assert len(result) > 0
class TestFindBashUnchanged:
"""_find_bash should be unaffected by the _find_shell change."""
def test_find_bash_still_prefers_bash(self):
"""_find_bash still returns bash (not $SHELL) on POSIX."""
result = _find_bash()
# On any system, _find_bash should return something containing "bash"
# or fall back to $SHELL or /bin/sh — but it should NOT prefer $SHELL
# over bash the way _find_shell does.
assert isinstance(result, str)
assert len(result) > 0
class TestFindBashCollapsedToPmShell:
"""_find_bash is now a thin wrapper over pm.shell(); the Windows
candidate ladder (HERMES_GIT_BASH_PATH → %LOCALAPPDATA%\\hermes\\git →
Program Files) and the ASLR diagnostic were deleted — the store is the
authority on bundled bash."""
@pytest.mark.platforms("windows")
def test_delegates_to_pm_shell(self, monkeypatch):
"""_find_bash returns whatever pm.shell() resolves (store bash or
provisioned PATH)."""
import tools.environments.local as local_mod
from tools.environments import local_gitbash_probe as gitbash_probe
monkeypatch.setattr(
"pm.shell.bash", lambda: r"C:\store\tools\git-x\usr\bin\bash.exe"
)
assert _find_bash() == r"C:\store\tools\git-x\usr\bin\bash.exe"
gitbash_probe._bash_starts_cache.clear()
def test_raises_when_pm_shell_finds_nothing(self, monkeypatch):
"""A store with no bash (and no PATH bash) surfaces a clear error
pointing at `hermes pm install` instead of hunting locations."""
import tools.environments.local as local_mod
from tools.environments import local_gitbash_probe as gitbash_probe
monkeypatch.setattr("pm.shell.bash", lambda: None)
with pytest.raises(RuntimeError) as exc_info:
local_mod._find_bash()
assert "No shell found" in str(exc_info.value)
assert "hermes pm install" in str(exc_info.value)
@pytest.mark.platforms("macos")
@pytest.mark.skipif(
not os.path.isfile("/bin/bash"),
reason="reproduces the macOS system-bash-3.2 login-shell swallow",
)
class TestMacosLoginShellSwallowRegression:
"""E2E regression for #42203: the actual failure is that system bash 3.2,
invoked as a login shell (`-lic`) with stdin=/dev/null and a
~/.bash_profile that `exec`s zsh, silently swallows the command (exit 0,
no output, no side effects). Prove (a) the bug exists with /bin/bash and
(b) the zsh path _find_shell prefers does NOT swallow."""
def _spawn_like_registry(self, shell, command, home, tmp_path):
import subprocess
env = dict(os.environ)
env["HOME"] = str(home)
# Mirror process_registry.spawn_local: [shell, "-lic", "set +m; <cmd>"]
# with stdin redirected to /dev/null.
return subprocess.run(
[shell, "-lic", f"set +m; {command}"],
stdin=subprocess.DEVNULL,
capture_output=True,
text=True,
env=env,
)
def test_system_bash_swallows_but_zsh_does_not(self, tmp_path):
# A .bash_profile that exec's zsh — the reported macOS shape.
home = tmp_path / "home"
home.mkdir()
(home / ".bash_profile").write_text("exec /bin/zsh -l\n")
# Use /bin/zsh explicitly rather than $SHELL. The reported bug is
# specifically "system bash 3.2 swallows, zsh does not", and $SHELL is
# not zsh everywhere this runs: GitHub's macOS runner exports
# SHELL=/bin/bash, which silently turned the control arm into a SECOND
# bash arm. It then swallowed (correctly, per the bug!) and the
# assertion read as "the fix path is broken" when nothing was broken.
# /bin/zsh is the macOS default login shell since Catalina and is
# present on every supported version.
zsh = "/bin/zsh"
if not os.path.isfile(zsh):
pytest.skip("no zsh available")
marker_bash = tmp_path / "bash_ran"
marker_zsh = tmp_path / "zsh_ran"
# /bin/bash login shell: command is swallowed (file NOT created).
self._spawn_like_registry("/bin/bash", f"echo x > {marker_bash}", home, tmp_path)
# zsh (what _find_shell prefers when $SHELL is zsh): command runs.
self._spawn_like_registry(zsh, f"echo x > {marker_zsh}", home, tmp_path)
# The FIX path (zsh) must run the command.
assert marker_zsh.exists(), "zsh path must run the command"
# Differential: when /bin/bash is the swallow-prone 3.x (macOS system
# bash), the login-shell invocation must demonstrably FAIL to run the
# command — that's the bug this PR routes around. Only assert the
# negative when we've confirmed a 3.x bash, so the test stays valid on
# boxes/CI with a newer /bin/bash that doesn't swallow.
ver = subprocess.run(
["/bin/bash", "--version"], capture_output=True, text=True
).stdout
if "version 3." in ver:
assert not marker_bash.exists(), (
"system bash 3.x login shell should swallow the command "
"(the #42203 bug); _find_shell routes around it by preferring zsh"
)
def test_find_shell_selects_working_shell_on_this_box(self, tmp_path):
"""_find_shell's choice must actually execute a background-style
command (regression against returning a swallow-prone shell)."""
shell = _find_shell()
marker = tmp_path / "ok_marker"
subprocess.run(
[shell, "-lic", f"set +m; echo ok > {marker}"],
stdin=subprocess.DEVNULL, capture_output=True, text=True,
)
assert marker.exists(), f"_find_shell()={shell} swallowed the command"