Lay groudwork to Closure compile JavaScript

third_party/closure_compiler/checker.py

Index: third_party/closure_compiler/checker.py
diff --git a/third_party/closure_compiler/checker.py b/third_party/closure_compiler/checker.py
new file mode 100755
index 0000000000000000000000000000000000000000..c504ad5f5749cf0b8d80b90296313c5dd4b298f5
--- /dev/null
+++ b/third_party/closure_compiler/checker.py
@@ -0,0 +1,135 @@
+#!/usr/bin/env python
+# Copyright 2014 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 argparse
+import os
+import subprocess
+import sys
+import tempfile
+
+
+class Checker(object):
+  _common_closure_args = [
+    "--accept_const_keyword",
+    "--language_in=ECMASCRIPT5",
+    "--summary_detail_level=3",
+    "--warning_level=VERBOSE",
+    "--jscomp_error=accessControls",
+    "--jscomp_error=ambiguousFunctionDecl",
+    "--jscomp_error=checkEventfulObjectDisposal",
+    "--jscomp_error=checkStructDictInheritance",
+    "--jscomp_error=checkTypes",
+    "--jscomp_error=checkVars",
+    "--jscomp_error=constantProperty",
+    "--jscomp_error=deprecated",
+    "--jscomp_error=duplicateMessage",
+    "--jscomp_error=es3",
+    "--jscomp_error=externsValidation",
+    "--jscomp_error=globalThis",
+    "--jscomp_error=invalidCasts",
+    "--jscomp_error=misplacedTypeAnnotation",
+    "--jscomp_error=missingProperties",
+    "--jscomp_error=missingReturn",
+    "--jscomp_error=nonStandardJsDocs",
+    "--jscomp_error=suspiciousCode",
+    "--jscomp_error=undefinedNames",
+    "--jscomp_error=undefinedVars",
+    "--jscomp_error=unknownDefines",
+    "--jscomp_error=uselessCode",
+    "--jscomp_error=visibility",
+  ]
+
+  _found_java = False
+
+  _jar_command = [
+    "java",
+    "-jar",
+    "-Xms1024m",
+    "-server",
+    "-XX:+TieredCompilation"
+  ]
+
+  def __init__(self, verbose=False):
+    self._current_dir = os.path.dirname(__file__)
+    self._compiler_jar = os.path.join(self._current_dir, "lib", "compiler.jar")
+    self._runner_jar = os.path.join(self._current_dir, "runner", "runner.jar")
+    self._verbose = verbose
+
+  def _clean_up(self):
+    if hasattr(self, '_args_file'):
+      self._debug("Deleting args file (" + self._args_file.name + ")")
+      os.remove(self._args_file.name)
+      del self._args_file
+
+  def _debug(self, msg, error=False):
+    if self._verbose:
+      if error:
+        print sys.stderr, "(ERROR) " + msg
+      else:
+        print "(INFO) " + msg
+
+  def _fatal(self, msg):
+    self._debug(msg, error=True)
+    self._clean_up()
+    sys.exit(1)
+
+  def _run_command(self, cmd):
+    cmd_str = " ".join(cmd)
+    self._debug("Running command: " + cmd_str)
+
+    devnull = open(os.devnull, "w")
+    return subprocess.Popen(
+        cmd_str, stdout=devnull, stderr=subprocess.PIPE, shell=True)
+
+  def _check_java_path(self):
+    if self._found_java:
+      return
+
+    proc = self._run_command(["which", "java"])
+    proc.communicate()
+    if proc.returncode == 0:
+      self._found_java = True
+    else:
+      self._fatal("Cannot find java (`which java` => %s)" % proc.returncode)
+
+  def _run_jar(self, jar, args=[]):
+    self._check_java_path()
+    return self._run_command(self._jar_command + [jar] + args)
+
+  def check(self, file, depends=[], externs=[]):
+    self._debug("FILE: " + file)
+
+    if file.endswith("_externs.js"):
+      self._debug("Skipping externs")
+      return
+
+    j = os.path.join
+    src_dir = j(self._current_dir, "..", "..")
+    # Omit blah_externs.js if we're compiling blah.js.
+    externs = [j(src_dir, e) for e in externs if file != e[:-11] + ".js"]
+
+    args = ["--js=" + file] + ["--externs=" + e for e in externs]
+    args_file_content = " " + " ".join(self._common_closure_args + args)
+    self._debug("Args: " + args_file_content.strip())
+
+    self._args_file = tempfile.NamedTemporaryFile(mode='wt', delete=False)
+    self._debug("Args file: " + self._args_file.name)
+    self._args_file.write(args_file_content)
+    self._args_file.close()
+
+    runner_args = ["--compiler-args-file=" + self._args_file.name]
+    runner_cmd = self._run_jar(self._runner_jar, args=runner_args)
+    (_, output) = runner_cmd.communicate()
+    output = output.strip()
+
+    if runner_cmd.returncode:
+      self._fatal(output)
+    else:
+      line_sep = os.linesep + "## "
+      self._debug("Output: " + line_sep + line_sep.join(output.splitlines()))
+   
+    self._clean_up()
+
+    return runner_cmd.returncode == 0