Merge branch 'bug/244' into 'master'

Display the local paths from the git hook

Instead of displaying the path to the temporary directory, as we always
have, it's been requested that we instead display the path to the file
that was copied to the temporary directory.

Closes #244

See merge request !154

docs/source/release-notes/3.3.0.rst

@@ -8,6 +8,9 @@ You can view the `3.3.0 milestone`_ on GitLab for more details.
 
 - Dramatically improve the performance of Flake8 (`GitLab!156`_)
 
+- Display the local file path instead of the temporary file path when
+  using the git hook (`GitLab#244`_)
+
 - Fix problem where hooks should only check \*.py files. (See also
   `GitLab#268`_)
 
@@ -17,6 +20,8 @@ You can view the `3.3.0 milestone`_ on GitLab for more details.
 .. links
 .. _3.3.0 milestone:
     https://gitlab.com/pycqa/flake8/milestones/16
+.. _GitLab#244:
+    https://gitlab.com/pycqa/flake8/issues/244
 .. _GitLab#251:
     https://gitlab.com/pycqa/flake8/issues/251
 .. _GitLab#268:

src/flake8/main/git.py

@@ -6,6 +6,7 @@
 """
 import contextlib
 import os
+import os.path
 import shutil
 import stat
 import subprocess
@@ -46,6 +47,7 @@ def hook(lazy=False, strict=False):
         app.options._running_from_vcs = True
         app.run_checks(filepaths)
 
+    update_paths(app.file_checker_manager, tempdir)
     app.report_errors()
     if strict:
         return app.result_count
@@ -204,6 +206,16 @@ def update_excludes(exclude_list, temporary_directory_path):
     ]
 
 
+def update_paths(checker_manager, temp_prefix):
+    temp_prefix_length = len(temp_prefix)
+    for checker in checker_manager.checkers:
+        filename = checker.display_name
+        if filename.startswith(temp_prefix):
+            checker.display_name = os.path.relpath(
+                filename[temp_prefix_length:]
+            )
+
+
 _HOOK_TEMPLATE = """#!{executable}
 import os
 import sys