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 100644
index 0000000000000000000000000000000000000000..b0190912da663dbf2f9a83a8adcfc103a94d8909
--- /dev/null
+++ b/third_party/closure_compiler/checker.py
@@ -0,0 +1,217 @@
+# 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.
+
+from collections import defaultdict
+import os
+import re
+import subprocess
+import sys
+import tempfile
+
+
+
+class LineNumber(object):
+  def __init__(self, file, line_number):
+    self.file = file
+    self.line_number = int(line_number)
+
+
+class FileCache(object):
+  _cache = defaultdict(str)
+    
+  def _read(self, file):
+    file = os.path.abspath(file)
+    self._cache[file] = self._cache[file] or open(file, "r").read()
+    return self._cache[file]
+
+  @staticmethod
+  def read(file):
+    return FileCache()._read(file)
+
+
+class Flattener(object):
+  _INCLUDE_REG = "<include[^>]+src=['\"]([^>]*)['\"]>"
+
+  def __init__(self, file):
+    self.index = 0
+    self.lines = self._get_file(file)
+
+    while self.index < len(self.lines):
+      current_line = self.lines[self.index]
+      match = re.search(self._INCLUDE_REG, current_line[2])
+      if match:
+        file_dir = os.path.dirname(current_line[0])
+        self._inline_file(os.path.join(file_dir, match.group(1)))
+      else:
+        self.index += 1
+
+    self.contents = "\n".join(l[2] for l in self.lines)
+
+  # Returns a list of tuples in the format: (file, line number, line contents).
+  def _get_file(self, file):
+    lines = FileCache.read(file).splitlines()
+    return [(file, lnum + 1, line) for lnum, line in enumerate(lines)]
+
+  def _inline_file(self, file):
+    lines = self._get_file(file)
+    self.lines = self.lines[:self.index] + lines + self.lines[self.index + 1:]
+
+  def get_file_from_line(self, line_number):
+    line_number = int(line_number) - 1
+    return LineNumber(self.lines[line_number][0], self.lines[line_number][1])
+
+
+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=checkStructDictInheritance",
+    "--jscomp_error=checkTypes",
+    "--jscomp_error=checkVars",
+    "--jscomp_error=constantProperty",
+    "--jscomp_error=deprecated",
+    "--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):
+    current_dir = os.path.join(os.path.dirname(__file__))
+    self._compiler_jar = os.path.join(current_dir, "lib", "compiler.jar")
+    self._runner_jar = os.path.join(current_dir, "runner", "runner.jar")
+    self._temp_files = []
+    self._verbose = verbose
+
+  def _clean_up(self):
+    if not self._temp_files:
+      return
+
+    self._debug("Deleting temporary files: " + ", ".join(self._temp_files))
+    for f in self._temp_files:
+      os.remove(f)
+    self._temp_files = []
+
+  def _debug(self, msg, error=False):
+    if self._verbose:
+      print "(INFO) " + msg
+
+  def _fatal(self, msg):
+    print >> sys.stderr, "(FATAL) " + msg
+    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 _fix_line_number(self, match):
+    real_file = self._flattener.get_file_from_line(match.group(1))
+    return "%s:%d" % (os.path.abspath(real_file.file), real_file.line_number)
+
+  def _fix_up_error(self, error):
+    if " first declared in " in error:
+      # Ignore "Variable x first declared in /same/file".
+      return ""
+
+    file = self._expanded_file
+    fixed = re.sub("%s:(\d+)" % file, self._fix_line_number, error)
+    return fixed.replace(file, os.path.abspath(self._file_arg))
+
+  def _format_errors(self, errors):
+    errors = filter(None, errors)
+    contents = ("\n" + "## ").join("\n\n".join(errors).splitlines())
+    return "## " + contents if contents else ""
+
+  def _create_temp_file(self, contents):
+    with tempfile.NamedTemporaryFile(mode='wt', delete=False) as tmp_file:
+      self._temp_files.append(tmp_file.name)
+      tmp_file.write(contents)
+    return tmp_file.name
+
+  def check(self, file, depends=[], externs=[]):
+    self._debug("FILE: " + file)
+
+    if file.endswith("_externs.js"):
+      self._debug("Skipping externs: " + file)
+      return
+
+    self._file_arg = file
+
+    tmp_dir = tempfile.gettempdir()
+    rel_path = lambda f: os.path.join(os.path.relpath(os.getcwd(), tmp_dir), f)
+
+    contents = ['<include src="%s">' % rel_path(f) for f in depends + [file]]
+    meta_file = self._create_temp_file("\n".join(contents))
+    self._debug("Meta file: " + meta_file)
+
+    self._flattener = Flattener(meta_file)
+    self._expanded_file = self._create_temp_file(self._flattener.contents)
+    self._debug("Expanded file: " + self._expanded_file)
+
+    args = ["--js=" + self._expanded_file] + ["--externs=" + e for e in externs]
+    args_file_content = " " + " ".join(self._common_closure_args + args)
+    self._debug("Args: " + args_file_content.strip())
+
+    args_file = self._create_temp_file(args_file_content)
+    self._debug("Args file: " + args_file)
+
+    runner_args = ["--compiler-args-file=" + args_file]
+    runner_cmd = self._run_jar(self._runner_jar, args=runner_args)
+    (_, stderr) = runner_cmd.communicate()
+
+    errors = stderr.strip().split("\n\n")
+    self._debug("Summary: " + errors.pop())
+
+    output = self._format_errors(map(self._fix_up_error, errors))
+    if runner_cmd.returncode:
+      self._fatal("Error in: " + file + ("\n" + output if output else ""))
+    elif output:
+      self._debug("Output: " + output)
+   
+    self._clean_up()
+
+    return runner_cmd.returncode == 0