1 files changed, 152 insertions, 0 deletions
diff --git a/tests/parse_shebang_test.py b/tests/parse_shebang_test.py
new file mode 100644
index 0000000..0bb19c7
--- /dev/null
+++ b/tests/parse_shebang_test.py
@@ -0,0 +1,152 @@
+import contextlib
+import os.path
+import shutil
+import sys
+
+import pytest
+
+from pre_commit import parse_shebang
+from pre_commit.envcontext import envcontext
+from pre_commit.envcontext import Var
+from pre_commit.util import make_executable
+
+
+def _echo_exe() -> str:
+    exe = shutil.which('echo')
+    assert exe is not None
+    return exe
+
+
+def test_file_doesnt_exist():
+    assert parse_shebang.parse_filename('herp derp derp') == ()
+
+
+def test_simple_case(tmpdir):
+    x = tmpdir.join('f')
+    x.write('#!/usr/bin/env echo')
+    make_executable(x.strpath)
+    assert parse_shebang.parse_filename(x.strpath) == ('echo',)
+
+
+def test_find_executable_full_path():
+    assert parse_shebang.find_executable(sys.executable) == sys.executable
+
+
+def test_find_executable_on_path():
+    assert parse_shebang.find_executable('echo') == _echo_exe()
+
+
+def test_find_executable_not_found_none():
+    assert parse_shebang.find_executable('not-a-real-executable') is None
+
+
+def write_executable(shebang, filename='run'):
+    os.mkdir('bin')
+    path = os.path.join('bin', filename)
+    with open(path, 'w') as f:
+        f.write(f'#!{shebang}')
+    make_executable(path)
+    return path
+
+
+@contextlib.contextmanager
+def bin_on_path():
+    bindir = os.path.join(os.getcwd(), 'bin')
+    with envcontext((('PATH', (bindir, os.pathsep, Var('PATH'))),)):
+        yield
+
+
+def test_find_executable_path_added(in_tmpdir):
+    path = os.path.abspath(write_executable('/usr/bin/env sh'))
+    assert parse_shebang.find_executable('run') is None
+    with bin_on_path():
+        assert parse_shebang.find_executable('run') == path
+
+
+def test_find_executable_path_ext(in_tmpdir):
+    """Windows exports PATHEXT as a list of extensions to automatically add
+    to executables when doing PATH searching.
+    """
+    exe_path = os.path.abspath(
+        write_executable('/usr/bin/env sh', filename='run.myext'),
+    )
+    env_path = {'PATH': os.path.dirname(exe_path)}
+    env_path_ext = dict(env_path, PATHEXT=os.pathsep.join(('.exe', '.myext')))
+    assert parse_shebang.find_executable('run') is None
+    assert parse_shebang.find_executable('run', _environ=env_path) is None
+    ret = parse_shebang.find_executable('run.myext', _environ=env_path)
+    assert ret == exe_path
+    ret = parse_shebang.find_executable('run', _environ=env_path_ext)
+    assert ret == exe_path
+
+
+def test_normexe_does_not_exist():
+    with pytest.raises(OSError) as excinfo:
+        parse_shebang.normexe('i-dont-exist-lol')
+    assert excinfo.value.args == ('Executable `i-dont-exist-lol` not found',)
+
+
+def test_normexe_does_not_exist_sep():
+    with pytest.raises(OSError) as excinfo:
+        parse_shebang.normexe('./i-dont-exist-lol')
+    assert excinfo.value.args == ('Executable `./i-dont-exist-lol` not found',)
+
+
+@pytest.mark.xfail(os.name == 'nt', reason='posix only')
+def test_normexe_not_executable(tmpdir):  # pragma: win32 no cover
+    tmpdir.join('exe').ensure()
+    with tmpdir.as_cwd(), pytest.raises(OSError) as excinfo:
+        parse_shebang.normexe('./exe')
+    assert excinfo.value.args == ('Executable `./exe` is not executable',)
+
+
+def test_normexe_is_a_directory(tmpdir):
+    with tmpdir.as_cwd():
+        tmpdir.join('exe').ensure_dir()
+        exe = os.path.join('.', 'exe')
+        with pytest.raises(OSError) as excinfo:
+            parse_shebang.normexe(exe)
+        msg, = excinfo.value.args
+        assert msg == f'Executable `{exe}` is a directory'
+
+
+def test_normexe_already_full_path():
+    assert parse_shebang.normexe(sys.executable) == sys.executable
+
+
+def test_normexe_gives_full_path():
+    assert parse_shebang.normexe('echo') == _echo_exe()
+    assert os.sep in _echo_exe()
+
+
+def test_normalize_cmd_trivial():
+    cmd = (_echo_exe(), 'hi')
+    assert parse_shebang.normalize_cmd(cmd) == cmd
+
+
+def test_normalize_cmd_PATH():
+    cmd = ('echo', '--version')
+    expected = (_echo_exe(), '--version')
+    assert parse_shebang.normalize_cmd(cmd) == expected
+
+
+def test_normalize_cmd_shebang(in_tmpdir):
+    echo = _echo_exe().replace(os.sep, '/')
+    path = write_executable(echo)
+    assert parse_shebang.normalize_cmd((path,)) == (echo, path)
+
+
+def test_normalize_cmd_PATH_shebang_full_path(in_tmpdir):
+    echo = _echo_exe().replace(os.sep, '/')
+    path = write_executable(echo)
+    with bin_on_path():
+        ret = parse_shebang.normalize_cmd(('run',))
+        assert ret == (echo, os.path.abspath(path))
+
+
+def test_normalize_cmd_PATH_shebang_PATH(in_tmpdir):
+    echo = _echo_exe()
+    path = write_executable('/usr/bin/env echo')
+    with bin_on_path():
+        ret = parse_shebang.normalize_cmd(('run',))
+        assert ret == (echo, os.path.abspath(path))