From 2eec5060e9ddbb2cb18add3ae88723279a2f2ea9 Mon Sep 17 00:00:00 2001
From: Sergey <sergey@skovorodkin.com>
Date: Sun, 14 Aug 2016 22:19:03 +0000
Subject: [PATCH 1/2] Consider `lazy` parameter in git.find_modified_files
 function

Refer to https://gitlab.com/pycqa/flake8/blob/867727f30408d53d743b1b6bb3cba4b7d33039c6/old/flake8/hooks.py#L34
---
 src/flake8/main/git.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/flake8/main/git.py b/src/flake8/main/git.py
index 8603f67..642ff38 100644
--- a/src/flake8/main/git.py
+++ b/src/flake8/main/git.py
@@ -141,7 +141,7 @@ def make_temporary_directory_from(destination, directory):
 
 def find_modified_files(lazy):
     diff_index = piped_process(
-        ['git', 'diff-index', '--cached', '--name-only',
+        ['git', 'diff-index', '' if lazy else '--cached', '--name-only',
          '--diff-filter=ACMRTUXB', 'HEAD'],
     )
 

From 941896218d477c3ec117d21dc9da45d4265269b8 Mon Sep 17 00:00:00 2001
From: Ian Cordasco <graffatcolmingov@gmail.com>
Date: Mon, 24 Oct 2016 18:29:45 -0500
Subject: [PATCH 2/2] Change how we apply lazy to the git hook

---
 src/flake8/main/git.py | 11 +++++++----
 tests/unit/test_git.py | 29 +++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 4 deletions(-)
 create mode 100644 tests/unit/test_git.py

diff --git a/src/flake8/main/git.py b/src/flake8/main/git.py
index 642ff38..d0c87d3 100644
--- a/src/flake8/main/git.py
+++ b/src/flake8/main/git.py
@@ -140,11 +140,14 @@ def make_temporary_directory_from(destination, directory):
 
 
 def find_modified_files(lazy):
-    diff_index = piped_process(
-        ['git', 'diff-index', '' if lazy else '--cached', '--name-only',
-         '--diff-filter=ACMRTUXB', 'HEAD'],
-    )
+    diff_index_cmd = [
+        'git', 'diff-index', '--cached', '--name-only',
+        '--diff-filter=ACMRTUXB', 'HEAD'
+    ]
+    if lazy:
+        diff_index_cmd.remove('--cached')
 
+    diff_index = piped_process(diff_index_cmd)
     (stdout, _) = diff_index.communicate()
     stdout = to_text(stdout)
     return stdout.splitlines()
diff --git a/tests/unit/test_git.py b/tests/unit/test_git.py
new file mode 100644
index 0000000..24d4b5b
--- /dev/null
+++ b/tests/unit/test_git.py
@@ -0,0 +1,29 @@
+"""Tests around functionality in the git integration."""
+import mock
+import pytest
+
+from flake8.main import git
+
+
+@pytest.mark.parametrize('lazy', [True, False])
+def test_find_modified_files(lazy):
+    """Confirm our logic for listing modified files."""
+    if lazy:
+        # Here --cached is missing
+        call = [
+            'git', 'diff-index', '--name-only', '--diff-filter=ACMRTUXB',
+            'HEAD'
+        ]
+    else:
+        call = [
+            'git', 'diff-index', '--cached', '--name-only',
+            '--diff-filter=ACMRTUXB', 'HEAD'
+        ]
+    mocked_popen = mock.Mock()
+    mocked_popen.communicate.return_value = ('', '')
+
+    with mock.patch('flake8.main.git.piped_process') as piped_process:
+        piped_process.return_value = mocked_popen
+        git.find_modified_files(lazy)
+
+    piped_process.assert_called_once_with(call)