Add check_case_conflict hook #21

.travis.yml

@@ -8,6 +8,10 @@ env: # These should match the tox env list
     - TOXENV=pypy3
 install: pip install coveralls tox --use-mirrors
 script: tox
+# Special snowflake.  Our tests depend on making real commits.
+before_install:
+  - git config --global user.name "Travis CI"
+  - git config --global user.email "user@example.com"
 after_success:
     - coveralls
 sudo: false

hooks.yaml

@@ -12,6 +12,13 @@
     language: python
     # Match all files
     files: ''
+-   id: check-case-conflict
+    name: Check for case conflicts
+    description: Check for files that would conflict in case-insensitive filesystems
+    entry: check-case-conflict
+    language: python
+    # Match all files
+    files: ''
 -   id: check-docstring-first
     name: Check docstring is first
     description: Checks a common error of defining a docstring after code.

pre_commit_hooks/check_added_large_files.py

@@ -8,15 +8,13 @@ import math
 import os
 import sys
 
-from plumbum import local
+from pre_commit_hooks.util import added_files
 
 
 def find_large_added_files(filenames, maxkb):
     # Find all added files that are also in the list of files pre-commit tells
     # us about
-    filenames = set(local['git'](
-        'diff', '--staged', '--name-only', '--diff-filter', 'A',
-    ).splitlines()) & set(filenames)
+    filenames = added_files() & set(filenames)
 
     retv = 0
     for filename in filenames:

pre_commit_hooks/check_case_conflict.py

@@ -0,0 +1,58 @@
+from __future__ import absolute_import
+from __future__ import print_function
+from __future__ import unicode_literals
+
+import argparse
+
+from plumbum import local
+
+from pre_commit_hooks.util import added_files
+
+
+def lower_set(iterable):
+    return set(x.lower() for x in iterable)
+
+
+def find_conflicting_filenames(filenames):
+    repo_files = set(local['git']('ls-files').splitlines())
+    relevant_files = set(filenames) | added_files()
+    repo_files -= relevant_files
+    retv = 0
+
+    # new file conflicts with existing file
+    conflicts = lower_set(repo_files) & lower_set(relevant_files)
+
+    # new file conflicts with other new file
+    lowercase_relevant_files = lower_set(relevant_files)
+    for filename in set(relevant_files):
+        if filename.lower() in lowercase_relevant_files:
+            lowercase_relevant_files.remove(filename.lower())
+        else:
+            conflicts.add(filename.lower())
+
+    if conflicts:
+        conflicting_files = [
+            x for x in repo_files | relevant_files
+            if x.lower() in conflicts
+        ]
+        for filename in sorted(conflicting_files):
+            print('Case-insensitivity conflict found: {0}'.format(filename))
+        retv = 1
+
+    return retv
+
+
+def main(argv=None):
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        'filenames', nargs='*',
+        help='Filenames pre-commit believes are changed.'
+    )
+
+    args = parser.parse_args(argv)
+
+    return find_conflicting_filenames(args.filenames)
+
+
+if __name__ == '__main__':
+    exit(main())

pre_commit_hooks/util.py

@@ -0,0 +1,11 @@
+from __future__ import absolute_import
+from __future__ import print_function
+from __future__ import unicode_literals
+
+from plumbum import local
+
+
+def added_files():
+    return set(local['git'](
+        'diff', '--staged', '--name-only', '--diff-filter', 'A',
+    ).splitlines())

pylintrc

@@ -17,3 +17,6 @@ ignored-classes=pytest
 [DESIGN]
 min-public-methods=0
 
+[SIMILARITIES]
+min-similarity-lines=5
+ignore-imports=yes

setup.py

@@ -38,6 +38,7 @@ setup(
         'console_scripts': [
             'autopep8-wrapper = pre_commit_hooks.autopep8_wrapper:main',
             'check-added-large-files = pre_commit_hooks.check_added_large_files:main',
+            'check-case-conflict = pre_commit_hooks.check_case_conflict:main',
             'check-docstring-first = pre_commit_hooks.check_docstring_first:main',
             'check-json = pre_commit_hooks.check_json:check_json',
             'check-yaml = pre_commit_hooks.check_yaml:check_yaml',

testing/util.py

@@ -1,3 +1,4 @@
+import io
 import os.path
 
 
@@ -6,3 +7,9 @@ TESTING_DIR = os.path.abspath(os.path.dirname(__file__))
 
 def get_resource_path(path):
     return os.path.join(TESTING_DIR, 'resources', path)
+
+
+def write_file(filename, contents):
+    """Hax because coveragepy chokes on nested context managers."""
+    with io.open(filename, 'w') as file_obj:
+        file_obj.write(contents)

tests/check_added_large_files_test.py

@@ -1,26 +1,11 @@
 from __future__ import absolute_import
 from __future__ import unicode_literals
 
-import io
-
-import pytest
 from plumbum import local
 
 from pre_commit_hooks.check_added_large_files import find_large_added_files
 from pre_commit_hooks.check_added_large_files import main
-
-
-@pytest.yield_fixture
-def temp_git_dir(tmpdir):
-    git_dir = tmpdir.join('gits').strpath
-    local['git']('init', git_dir)
-    yield git_dir
-
-
-def write_file(filename, contents):
-    """Hax because coveragepy chokes on nested context managers."""
-    with io.open(filename, 'w') as file_obj:
-        file_obj.write(contents)
+from testing.util import write_file
 
 
 def test_nothing_added(temp_git_dir):

tests/check_case_conflict_test.py

@@ -0,0 +1,66 @@
+from __future__ import absolute_import
+from __future__ import unicode_literals
+
+from plumbum import local
+
+from pre_commit_hooks.check_case_conflict import find_conflicting_filenames
+from pre_commit_hooks.check_case_conflict import main
+from testing.util import write_file
+
+
+def test_nothing_added(temp_git_dir):
+    with local.cwd(temp_git_dir):
+        assert find_conflicting_filenames(['f.py']) == 0
+
+
+def test_adding_something(temp_git_dir):
+    with local.cwd(temp_git_dir):
+        write_file('f.py', "print('hello world')")
+        local['git']('add', 'f.py')
+
+        assert find_conflicting_filenames(['f.py']) == 0
+
+
+def test_adding_something_with_conflict(temp_git_dir):
+    with local.cwd(temp_git_dir):
+        write_file('f.py', "print('hello world')")
+        local['git']('add', 'f.py')
+        write_file('F.py', "print('hello world')")
+        local['git']('add', 'F.py')
+
+        assert find_conflicting_filenames(['f.py', 'F.py']) == 1
+
+
+def test_added_file_not_in_pre_commits_list(temp_git_dir):
+    with local.cwd(temp_git_dir):
+        write_file('f.py', "print('hello world')")
+        local['git']('add', 'f.py')
+
+        assert find_conflicting_filenames(['g.py']) == 0
+
+
+def test_file_conflicts_with_committed_file(temp_git_dir):
+    with local.cwd(temp_git_dir):
+        write_file('f.py', "print('hello world')")
+        local['git']('add', 'f.py')
+        local['git']('commit', '--no-verify', '-m', 'Add f.py')
+
+        write_file('F.py', "print('hello world')")
+        local['git']('add', 'F.py')
+
+        assert find_conflicting_filenames(['F.py']) == 1
+
+
+def test_integration(temp_git_dir):
+    with local.cwd(temp_git_dir):
+        assert main(argv=[]) == 0
+
+        write_file('f.py', "print('hello world')")
+        local['git']('add', 'f.py')
+
+        assert main(argv=['f.py']) == 0
+
+        write_file('F.py', "print('hello world')")
+        local['git']('add', 'F.py')
+
+        assert main(argv=['F.py']) == 1

tests/conftest.py

@@ -0,0 +1,13 @@
+from __future__ import absolute_import
+from __future__ import print_function
+from __future__ import unicode_literals
+
+import pytest
+from plumbum import local
+
+
+@pytest.yield_fixture
+def temp_git_dir(tmpdir):
+    git_dir = tmpdir.join('gits').strpath
+    local['git']('init', git_dir)
+    yield git_dir