Add a no commit to specific branch hook. (#185) * add no commit code and config * add the code * remove version tweak * fix logic, remove newline * add Tests and cleanup testing issues * remove extraneous modules * cleanup some pep8 and flake issues * reorder imports * more fixes for syntax checking * code cleanup based off asottile comments * Use Contractions Properly, alphabatize new hook. * Adding support for branches with a slash in them.

diff --git a/.pre-commit-hooks.yaml b/.pre-commit-hooks.yaml
index 0604585..bda3f76 100644
--- a/.pre-commit-hooks.yaml
+++ b/.pre-commit-hooks.yaml

@@ -129,6 +129,12 @@
     entry: name-tests-test
     language: python
     files: tests/.+\.py$
+-   id: no-commit-to-branch
+    name: "Don't commit to branch"
+    entry: no-commit-to-branch
+    language: python
+    files: .*
+    always_run: true
 -   id: pyflakes
     name: Pyflakes (DEPRECATED, use flake8)
     description: This hook runs pyflakes. (This is deprecated, use flake8).

diff --git a/README.md b/README.md
index 031edfd..723136d 100644
--- a/README.md
+++ b/README.md

@@ -56,6 +56,8 @@
 - `forbid-new-submodules` - Prevent addition of new git submodules.
 - `name-tests-test` - Assert that files in tests/ end in `_test.py`.
     - Use `args: ['--django']` to match `test*.py` instead.
+- `no-commit-to-branch` - Protect specific branches from direct checkins.
+    - Use `args: -b <branch> ` to set the branch. `master` is the default if no argument is set.
 - `pyflakes` - Run pyflakes on your python files.
 - `pretty-format-json` - Checks that all your JSON files are pretty.  "Pretty"
   here means that keys are sorted and indented.  You can configure this with

diff --git a/hooks.yaml b/hooks.yaml
index 0604585..bda3f76 100644
--- a/hooks.yaml
+++ b/hooks.yaml

@@ -129,6 +129,12 @@
     entry: name-tests-test
     language: python
     files: tests/.+\.py$
+-   id: no-commit-to-branch
+    name: "Don't commit to branch"
+    entry: no-commit-to-branch
+    language: python
+    files: .*
+    always_run: true
 -   id: pyflakes
     name: Pyflakes (DEPRECATED, use flake8)
     description: This hook runs pyflakes. (This is deprecated, use flake8).

diff --git a/pre_commit_hooks/no_commit_to_branch.py b/pre_commit_hooks/no_commit_to_branch.py
new file mode 100644
index 0000000..4aa3535
--- /dev/null
+++ b/pre_commit_hooks/no_commit_to_branch.py

@@ -0,0 +1,25 @@
+from __future__ import print_function
+
+import argparse
+import sys
+
+from pre_commit_hooks.util import cmd_output
+
+
+def is_on_branch(protected):
+    branch = cmd_output('git', 'symbolic-ref', 'HEAD')
+    chunks = branch.strip().split('/')
+    return '/'.join(chunks[2:]) == protected
+
+
+def main(argv=[]):
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        '-b', '--branch', default='master', help='branch to disallow commits to')
+    args = parser.parse_args(argv)
+
+    return int(is_on_branch(args.branch))
+
+
+if __name__ == '__main__':
+    sys.exit(main(sys.argv))

diff --git a/setup.py b/setup.py
index 68a8664..9db61a4 100644
--- a/setup.py
+++ b/setup.py

@@ -52,6 +52,7 @@
             'fix-encoding-pragma = pre_commit_hooks.fix_encoding_pragma:main',
             'forbid-new-submodules = pre_commit_hooks.forbid_new_submodules:main',
             'name-tests-test = pre_commit_hooks.tests_should_end_in_test:validate_files',
+            'no-commit-to-branch = pre_commit_hooks.no_commit_to_branch:main',
             'pretty-format-json = pre_commit_hooks.pretty_format_json:pretty_format_json',
             'requirements-txt-fixer = pre_commit_hooks.requirements_txt_fixer:fix_requirements_txt',
             'trailing-whitespace-fixer = pre_commit_hooks.trailing_whitespace_fixer:fix_trailing_whitespace',

diff --git a/tests/check_no_commit_to_branch_test.py b/tests/check_no_commit_to_branch_test.py
new file mode 100644
index 0000000..99af938
--- /dev/null
+++ b/tests/check_no_commit_to_branch_test.py

@@ -0,0 +1,47 @@
+from __future__ import absolute_import
+from __future__ import unicode_literals
+
+from pre_commit_hooks.no_commit_to_branch import is_on_branch
+from pre_commit_hooks.no_commit_to_branch import main
+from pre_commit_hooks.util import cmd_output
+
+
+def test_other_branch(temp_git_dir):
+    with temp_git_dir.as_cwd():
+        cmd_output('git', 'checkout', '-b', 'anotherbranch')
+        assert is_on_branch('master') is False
+
+
+def test_multi_branch(temp_git_dir):
+    with temp_git_dir.as_cwd():
+        cmd_output('git', 'checkout', '-b', 'another/branch')
+        assert is_on_branch('master') is False
+
+
+def test_multi_branch_fail(temp_git_dir):
+    with temp_git_dir.as_cwd():
+        cmd_output('git', 'checkout', '-b', 'another/branch')
+        assert is_on_branch('another/branch') is True
+
+
+def test_master_branch(temp_git_dir):
+    with temp_git_dir.as_cwd():
+        assert is_on_branch('master') is True
+
+
+def test_main_b_call(temp_git_dir):
+    with temp_git_dir.as_cwd():
+        cmd_output('git', 'checkout', '-b', 'other')
+        assert main(['-b', 'other']) == 1
+
+
+def test_main_branch_call(temp_git_dir):
+    with temp_git_dir.as_cwd():
+        cmd_output('git', 'checkout', '-b', 'other')
+        assert main(['--branch', 'other']) == 1
+
+
+def test_main_default_call(temp_git_dir):
+    with temp_git_dir.as_cwd():
+        cmd_output('git', 'checkout', '-b', 'anotherbranch')
+        assert main() == 0