1 files changed, 39 insertions, 0 deletions
diff --git a/src/flake8/main/vcs.py b/src/flake8/main/vcs.py
new file mode 100644
index 0000000..6f7499e
--- /dev/null
+++ b/src/flake8/main/vcs.py
@@ -0,0 +1,39 @@
+"""Module containing some of the logic for our VCS installation logic."""
+from flake8 import exceptions as exc
+from flake8.main import git
+from flake8.main import mercurial
+
+
+# NOTE(sigmavirus24): In the future, we may allow for VCS hooks to be defined
+# as plugins, e.g., adding a flake8.vcs entry-point. In that case, this
+# dictionary should disappear, and this module might contain more code for
+# managing those bits (in conjuntion with flake8.plugins.manager).
+_INSTALLERS = {
+    'git': git.install,
+    'mercurial': mercurial.install,
+}
+
+
+def install(option, option_string, value, parser):
+    """Determine which version control hook to install.
+
+    For more information about the callback signature, see:
+    https://docs.python.org/2/library/optparse.html#optparse-option-callbacks
+    """
+    installer = _INSTALLERS.get(value)
+    errored = False
+    successful = False
+    try:
+        successful = installer()
+    except exc.HookInstallationError as hook_error:
+        print(str(hook_error))
+        errored = True
+
+    if not successful:
+        print('Could not find the {0} directory'.format(value))
+    raise SystemExit(not successful and errored)
+
+
+def choices():
+    """Return the list of VCS choices."""
+    return list(_INSTALLERS.keys())