Add a run_eslint wrapper script

common/eslint/eslint/__init__.py

Index: common/eslint/eslint/__init__.py
diff --git a/common/eslint/eslint/__init__.py b/common/eslint/eslint/__init__.py
new file mode 100644
index 0000000000000000000000000000000000000000..5b2ba5212ccb6f4897f0062303495818a79cc3c4
--- /dev/null
+++ b/common/eslint/eslint/__init__.py
@@ -0,0 +1,82 @@
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import os
+import subprocess
+import sys
+
+
+_CATAPULT_PATH = os.path.join(
+    os.path.dirname(os.path.abspath(__file__)),
+    os.path.pardir, os.path.pardir, os.path.pardir)
+
+
+def _AddToPathIfNeeded(path):
+  if path not in sys.path:
+    sys.path.insert(0, path)
+
+
+def _UpdateSysPathIfNeeded():
+  _AddToPathIfNeeded(os.path.join(_CATAPULT_PATH, 'common', 'node_runner'))
+  _AddToPathIfNeeded(os.path.join(_CATAPULT_PATH, 'common', 'py_utils'))
+
+
+_UpdateSysPathIfNeeded()
+
+
+import py_utils
+from node_runner import node_util
+
+
+BASE_ESLINT_CMD = [
+  node_util.GetNodePath(),
+  os.path.join(node_util.GetNodeModulesPath(), 'eslint', 'bin', 'eslint.js'),
+  '--color'
+]
+
+
+DEFAULT_ESLINT_CONFIG = os.path.join(
+    py_utils.GetCatapultDir(), 'common', 'eslint', '.eslintrc')
+
+
+DEFAULT_ESLINT_RULES_DIR = os.path.join(
+    py_utils.GetCatapultDir(), 'common', 'eslint', 'rules')
+
+
+def _CreateEslintCommand(config, rulesdir):
+  return BASE_ESLINT_CMD + [
+      '--config', config,
+      '--rulesdir', rulesdir
+  ]
+
+
+def RunEslintOnDirs(dirs,
+                    config=DEFAULT_ESLINT_CONFIG,
+                    rules_dir=DEFAULT_ESLINT_RULES_DIR):
+  if type(dirs) is not list or len(dirs) == 0:
+    raise ValueError('Must specify a non-empty list of directories to lint.')
+
+  try:
+    find_cmd = ['find'] + dirs + ['-name', '*.html']
+    eslint_cmd = _CreateEslintCommand(config, rules_dir)
+    p1 = subprocess.Popen(find_cmd, stdout=subprocess.PIPE)
+    output = subprocess.check_output(['xargs'] + eslint_cmd, stdin=p1.stdout)
+    p1.wait()
+    return output
+  except subprocess.CalledProcessError as e:
+    return e.output
+
+
+def RunEslintOnFiles(filenames,
+                     config=DEFAULT_ESLINT_CONFIG,
+                     rules_dir=DEFAULT_ESLINT_RULES_DIR):
+  if type(filenames) is not list or len(filenames) == 0:
+    raise ValueError('Must specify a non-empty list of files to lint.')
+
+  try:
+    eslint_cmd = _CreateEslintCommand(config, rules_dir)
+    return subprocess.check_output(eslint_cmd + filenames,
+                                   stderr=subprocess.STDOUT)
+  except subprocess.CalledProcessError as e:
+    return e.output