Added the additional_dependencies config parameter

Added the ability to specify additional dependencies to be installed in
the pre-commit environment. Fixed broken tests.

pre_commit/languages/node.py

@@ -23,7 +23,8 @@ def in_env(repo_cmd_runner, language_version):
     yield NodeEnv(repo_cmd_runner, language_version)
 
 
-def install_environment(repo_cmd_runner, version='default'):
+def install_environment(repo_cmd_runner, version='default',
+                        additional_dependencies=None):
     assert repo_cmd_runner.exists('package.json')
     directory = helpers.environment_dir(ENVIRONMENT_DIR, version)
 
@@ -41,6 +42,9 @@ def install_environment(repo_cmd_runner, version='default'):
 
         with in_env(repo_cmd_runner, version) as node_env:
             node_env.run("cd '{prefix}' && npm install -g")
+            if additional_dependencies:
+                node_env.run("cd '{prefix}' && npm install -g " +
+                             (' ').join(additional_dependencies))
 
 
 def run_hook(repo_cmd_runner, hook, file_args):

pre_commit/languages/pcre.py

@@ -9,7 +9,8 @@ from pre_commit.util import shell_escape
 ENVIRONMENT_DIR = None
 
 
-def install_environment(repo_cmd_runner, version='default'):
+def install_environment(repo_cmd_runner, version='default',
+                        additional_dependencies=None):
     """Installation for pcre type is a noop."""
     raise AssertionError('Cannot install pcre repo.')
 

pre_commit/languages/python.py

@@ -42,7 +42,8 @@ def norm_version(version):
     return version
 
 
-def install_environment(repo_cmd_runner, version='default'):
+def install_environment(repo_cmd_runner, version='default',
+                        additional_dependencies=None):
     assert repo_cmd_runner.exists('setup.py')
     directory = helpers.environment_dir(ENVIRONMENT_DIR, version)
 
@@ -57,6 +58,9 @@ def install_environment(repo_cmd_runner, version='default'):
         repo_cmd_runner.run(venv_cmd)
         with in_env(repo_cmd_runner, version) as env:
             env.run("cd '{prefix}' && pip install .")
+            if additional_dependencies:
+                env.run("cd '{prefix}' && pip install -U" +
+                        (' ').join(additional_dependencies))
 
 
 def run_hook(repo_cmd_runner, hook, file_args):

pre_commit/languages/ruby.py

@@ -78,7 +78,8 @@ def _install_ruby(environment, version):
         environment.run('rbenv install {0}'.format(version))
 
 
-def install_environment(repo_cmd_runner, version='default'):
+def install_environment(repo_cmd_runner, version='default',
+                        additional_dependencies=None):
     directory = helpers.environment_dir(ENVIRONMENT_DIR, version)
     with clean_path_on_failure(repo_cmd_runner.path(directory)):
         # TODO: this currently will fail if there's no version specified and
@@ -91,6 +92,11 @@ def install_environment(repo_cmd_runner, version='default'):
                 'cd {prefix} && gem build *.gemspec'
                 ' && gem install --no-ri --no-rdoc *.gem',
             )
+            if additional_dependencies:
+                ruby_env.run(
+                    'cd {prefix} && gem install --no-document ' + (' ').join(
+                        additional_dependencies)
+                )
 
 
 def run_hook(repo_cmd_runner, hook, file_args):

pre_commit/languages/script.py

@@ -6,7 +6,8 @@ from pre_commit.languages.helpers import file_args_to_stdin
 ENVIRONMENT_DIR = None
 
 
-def install_environment(repo_cmd_runner, version='default'):
+def install_environment(repo_cmd_runner, version='default',
+                        additional_dependencies=None):
     """Installation for script type is a noop."""
     raise AssertionError('Cannot install script repo.')
 

pre_commit/languages/system.py

@@ -8,7 +8,8 @@ from pre_commit.languages.helpers import file_args_to_stdin
 ENVIRONMENT_DIR = None
 
 
-def install_environment(repo_cmd_runner, version='default'):
+def install_environment(repo_cmd_runner, version='default',
+                        additional_dependencies=None):
     """Installation for system type is a noop."""
     raise AssertionError('Cannot install system repo.')
 

pre_commit/repository.py

@@ -2,6 +2,7 @@ from __future__ import unicode_literals
 
 import logging
 import shutil
+from collections import defaultdict
 
 from cached_property import cached_property
 
@@ -49,6 +50,14 @@ class Repository(object):
             for _, hook in self.hooks
         )
 
+    @cached_property
+    def additional_dependencies(self):
+        dep_dict = defaultdict(lambda: defaultdict(set))
+        for _, hook in self.hooks:
+            dep_dict[hook['language']][hook['language_version']].update(
+                hook.get('dependencies', []))
+        return dep_dict
+
     @cached_property
     def hooks(self):
         # TODO: merging in manifest dicts is a smell imo
@@ -107,7 +116,9 @@ class Repository(object):
             if self.cmd_runner.exists(directory):
                 shutil.rmtree(self.cmd_runner.path(directory))
 
-            language.install_environment(self.cmd_runner, language_version)
+            language.install_environment(
+                self.cmd_runner, language_version,
+                self.additional_dependencies[language_name][language_version])
             # Touch the .installed file (atomic) to indicate we've installed
             open(self.cmd_runner.path(directory, '.installed'), 'w').close()
 

tests/languages/all_test.py

@@ -11,10 +11,10 @@ from pre_commit.languages.all import languages
 @pytest.mark.parametrize('language', all_languages)
 def test_install_environment_argspec(language):
     expected_argspec = inspect.ArgSpec(
-        args=['repo_cmd_runner', 'version'],
+        args=['repo_cmd_runner', 'version', 'additional_dependencies'],
         varargs=None,
         keywords=None,
-        defaults=('default',),
+        defaults=('default', None),
     )
     argspec = inspect.getargspec(languages[language].install_environment)
     assert argspec == expected_argspec