Nicer interfaces

pre_commit/languages/python.py

@@ -1,10 +1,34 @@
 
+import contexlib
 from plumbum import local
-import subprocess
 
 PY_ENV = 'py_env'
 
 
+class PythonEnv(object):
+    def __init__(self):
+        self.env_prefix = '. {0}/bin/activate &&'.format(PY_ENV)
+
+    def run(self, cmd):
+        return local['bash']['-c', ' '.join([self.env_prefix, cmd])]()
+
+
+NODE_ENV = 'node_env'
+
+class NodeEnv(object):
+    def __init__(self, py_env):
+        self.py_env = py_env
+        self.env_prefix = '. {0}/bin/activate &&'.format(NODE_ENV)
+
+    def run(self, cmd):
+        return self.py_env.run(' '.join(self.env_prefix, cmd))
+
+
+@contexlib.contextmanager
+def in_env():
+    yield PythonEnv()
+
+
 def install_environment():
     assert local.path('setup.py').exists()
     # Return immediately if we already have a virtualenv
@@ -13,25 +37,13 @@ def install_environment():
 
     # Install a virtualenv
     local['virtualenv'][PY_ENV]()
-    local['bash']['-c', 'source {0}/bin/activate && pip install .'.format(PY_ENV)]()
+    with in_env() as env:
+        env.run('pip install .')
 
 
 def run_hook(hook, file_args):
     # TODO: batch filenames
-    process = subprocess.Popen(
-        ['bash', '-c', ' '.join(
-            ['source {0}/bin/activate &&'.format(PY_ENV)] +
-            [hook['entry']] + hook.get('args', []) + list(file_args)
-        )],
-        stdout=subprocess.PIPE, stderr=subprocess.PIPE,
-    )
-    ret = process.communicate()
-
-    return (process.returncode,) + ret
-
-    return local['bash'][
-        '-c', ' '.join(
-            ['source {0}/bin/activate &&'.format(PY_ENV)] +
-            [hook['entry']] + hook.get('args', []) + list(file_args)
-        )
-    ].run()
+    with in_env() as env:
+        env = env
+        # MAGIC
+        pass