New hook 'destroyed-symlinks' to detect symlinks which are changed to regular files with a content of a path which that symlink was pointing to; move zsplit to util

tests/check_executables_have_shebangs_test.py

@@ -102,16 +102,6 @@ def test_check_git_filemode_failing(tmpdir):
         assert check_executables_have_shebangs._check_git_filemode(files) == 1
 
 
-@pytest.mark.parametrize('out', ('\0f1\0f2\0', '\0f1\0f2', 'f1\0f2\0'))
-def test_check_zsplits_correctly(out):
-    assert check_executables_have_shebangs.zsplit(out) == ['f1', 'f2']
-
-
-@pytest.mark.parametrize('out', ('\0\0', '\0', ''))
-def test_check_zsplit_returns_empty(out):
-    assert check_executables_have_shebangs.zsplit(out) == []
-
-
 @pytest.mark.parametrize(
     ('content', 'mode', 'expected'),
     (

tests/destroyed_symlinks_test.py

@@ -0,0 +1,74 @@
+import os
+import subprocess
+
+import pytest
+
+from pre_commit_hooks.destroyed_symlinks import find_destroyed_symlinks
+from pre_commit_hooks.destroyed_symlinks import main
+
+TEST_SYMLINK = 'test_symlink'
+TEST_SYMLINK_TARGET = '/doesnt/really/matters'
+TEST_FILE = 'test_file'
+TEST_FILE_RENAMED = f'{TEST_FILE}_renamed'
+
+
+@pytest.fixture
+def repo_with_destroyed_symlink(tmpdir):
+    source_repo = tmpdir.join('src')
+    os.makedirs(source_repo, exist_ok=True)
+    test_repo = tmpdir.join('test')
+    with source_repo.as_cwd():
+        subprocess.check_call(('git', 'init'))
+        os.symlink(TEST_SYMLINK_TARGET, TEST_SYMLINK)
+        with open(TEST_FILE, 'w') as f:
+            print('some random content', file=f)
+        subprocess.check_call(('git', 'add', '.'))
+        subprocess.check_call(
+            ('git', 'commit', '--no-gpg-sign', '-m', 'initial'),
+        )
+        assert b'120000 ' in subprocess.check_output(
+            ('git', 'cat-file', '-p', 'HEAD^{tree}'),
+        )
+    subprocess.check_call(
+        ('git', '-c', 'core.symlinks=false', 'clone', source_repo, test_repo),
+    )
+    with test_repo.as_cwd():
+        subprocess.check_call(
+            ('git', 'config', '--local', 'core.symlinks', 'true'),
+        )
+        subprocess.check_call(('git', 'mv', TEST_FILE, TEST_FILE_RENAMED))
+    assert not os.path.islink(test_repo.join(TEST_SYMLINK))
+    yield test_repo
+
+
+def test_find_destroyed_symlinks(repo_with_destroyed_symlink):
+    with repo_with_destroyed_symlink.as_cwd():
+        assert find_destroyed_symlinks([]) == []
+        assert main([]) == 0
+
+        subprocess.check_call(('git', 'add', TEST_SYMLINK))
+        assert find_destroyed_symlinks([TEST_SYMLINK]) == [TEST_SYMLINK]
+        assert find_destroyed_symlinks([]) == []
+        assert main([]) == 0
+        assert find_destroyed_symlinks([TEST_FILE_RENAMED, TEST_FILE]) == []
+        ALL_STAGED = [TEST_SYMLINK, TEST_FILE_RENAMED]
+        assert find_destroyed_symlinks(ALL_STAGED) == [TEST_SYMLINK]
+        assert main(ALL_STAGED) != 0
+
+        with open(TEST_SYMLINK, 'a') as f:
+            print(file=f)  # add trailing newline
+        subprocess.check_call(['git', 'add', TEST_SYMLINK])
+        assert find_destroyed_symlinks(ALL_STAGED) == [TEST_SYMLINK]
+        assert main(ALL_STAGED) != 0
+
+        with open(TEST_SYMLINK, 'w') as f:
+            print('0' * len(TEST_SYMLINK_TARGET), file=f)
+        subprocess.check_call(('git', 'add', TEST_SYMLINK))
+        assert find_destroyed_symlinks(ALL_STAGED) == []
+        assert main(ALL_STAGED) == 0
+
+        with open(TEST_SYMLINK, 'w') as f:
+            print('0' * (len(TEST_SYMLINK_TARGET) + 3), file=f)
+        subprocess.check_call(('git', 'add', TEST_SYMLINK))
+        assert find_destroyed_symlinks(ALL_STAGED) == []
+        assert main(ALL_STAGED) == 0

tests/util_test.py

@@ -2,6 +2,7 @@ import pytest
 
 from pre_commit_hooks.util import CalledProcessError
 from pre_commit_hooks.util import cmd_output
+from pre_commit_hooks.util import zsplit
 
 
 def test_raises_on_error():
@@ -12,3 +13,13 @@ def test_raises_on_error():
 def test_output():
     ret = cmd_output('sh', '-c', 'echo hi')
     assert ret == 'hi\n'
+
+
+@pytest.mark.parametrize('out', ('\0f1\0f2\0', '\0f1\0f2', 'f1\0f2\0'))
+def test_check_zsplits_str_correctly(out):
+    assert zsplit(out) == ['f1', 'f2']
+
+
+@pytest.mark.parametrize('out', ('\0\0', '\0', ''))
+def test_check_zsplit_returns_empty(out):
+    assert zsplit(out) == []