Resolves cwd problem

pre_commit/repository.py

@@ -7,12 +7,15 @@ from pre_commit.clientlib.validate_manifest import load_manifest
 from pre_commit.hooks_workspace import in_hooks_workspace
 from pre_commit.languages.all import languages
 from pre_commit.ordereddict import OrderedDict
+from pre_commit.prefixed_command_runner import PrefixedCommandRunner
 from pre_commit.util import cached_property
 
 
 class Repository(object):
     def __init__(self, repo_config):
         self.repo_config = repo_config
+        self.__created = False
+        self.__installed = False
 
     @cached_property
     def repo_url(self):
@@ -43,13 +46,17 @@ class Repository(object):
                 for hook in load_manifest(C.MANIFEST_FILE)
             )
 
-    @contextlib.contextmanager
-    def in_checkout(self):
-        with in_hooks_workspace():
-            # SMELL:
-            self.create()
-            with local.cwd(self.sha):
-                yield
+    def get_cmd_runner(self, hooks_cmd_runner):
+        return PrefixedCommandRunner.from_command_runner(
+            hooks_cmd_runner, self.sha,
+        )
+
+    def require_created(self):
+        if self.__created:
+            return
+
+        self.create()
+        self.__created = True
 
     def create(self):
         with in_hooks_workspace():
@@ -61,13 +68,42 @@ class Repository(object):
             with self.in_checkout():
                 local['git']['checkout', self.sha]()
 
-    def install(self):
-        with self.in_checkout():
-            for language in C.SUPPORTED_LANGUAGES:
-                if language in self.languages:
-                    languages[language].install_environment()
+    def require_installed(self, cmd_runner):
+        if self.__installed:
+            return
 
-    def run_hook(self, hook_id, file_args):
-        with self.in_checkout():
-            hook = self.hooks[hook_id]
-            return languages[hook['language']].run_hook(hook, file_args)
+        self.install(cmd_runner)
+
+    def install(self, cmd_runner):
+        """Install the hook repository.
+
+        Args:
+            cmd_runner - A `PrefixedCommandRunner` bound to the hooks workspace
+        """
+        self.require_created()
+        repo_cmd_runner = self.get_cmd_runner(cmd_runner)
+        for language in C.SUPPORTED_LANGUAGES:
+            if language in self.languages:
+                languages[language].install_environment(repo_cmd_runner)
+
+    @contextlib.contextmanager
+    def in_checkout(self):
+        self.require_created()
+        with in_hooks_workspace():
+            with local.cwd(self.sha):
+                yield
+
+    def run_hook(self, cmd_runner, hook_id, file_args):
+        """Run a hook.
+
+        Args:
+            cmd_runner - A `PrefixedCommandRunner` bound to the hooks workspace
+            hook_id - Id of the hook
+            file_args - List of files to run
+        """
+        self.require_installed(cmd_runner)
+        repo_cmd_runner = self.get_cmd_runner(cmd_runner)
+        hook = self.hooks[hook_id]
+        return languages[hook['language']].run_hook(
+            repo_cmd_runner, hook, file_args,
+        )