Script for BBEdit to perform check (but not compilation) of JavaScript program using Google's Closure Compiler.

Check JavaScript with Closure Compiler.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

# Check JavaScript with Closure Compiler: 
# Script to perform check (but not compilation) of front window using
# Google's Closure Compiler.
# Place this script in the script menu and invoke it from BBEdit.

# Copyright Jay Lieske Jr.
# 11 May 2016

import sys, re, os, subprocess, struct
from Foundation import NSAppleEventDescriptor
from ScriptingBridge import SBApplication

def getFrontBBEditDocument():
    BBEdit = SBApplication.applicationWithBundleIdentifier_(
      "com.barebones.BBEdit")
    document = BBEdit.documents().firstObject()
    if document:
        return document.file().path()
    else:
        return None


def invokeClosureCompiler(filePath):
    """Call the Closure Compiler to check the filePath, returning stderr
    from the run."""
    command = []
    # Closure Compiler driver script can be installed by Homebrew.
    # Annoyingly, the script menu does not respect the shell path.
    command.append("/usr/local/bin/closure-compiler")
    command.extend(["--checks-only", "--warning_level=VERBOSE",
                    "--process_common_js_modules"])
    command.append(filePath)
    # Run the compiler and capture the output.
    try:
        output = subprocess.check_output(command, stderr=subprocess.STDOUT)
    except subprocess.CalledProcessError, e:
        output = e.output
    return output


def fourCharCode(string):
  "Convert a four-char code string into a 32-bit int."
  return struct.unpack('>I', string)[0]


def processMessages(compilerOutput):
    # Matches just the error messages from the compiler:
    # a file name, followed by a colon and line number, an optional column number,
    # and then the error message.
    # Since BBEdit doesn't accept column numbers, it doesn't try to parse
    # other positional feedback from the compiler.
    # To avoid false matches, this version doesn't allow spaces in file names.
    pat = re.compile(r"^([^: ]+):(\d+)(?:[.:-]\d+)*[:\s]+(.+)$")

    # Distinguish warning from errors.
    warning = re.compile(r"warning", re.IGNORECASE)
    warning_kind = NSAppleEventDescriptor.descriptorWithEnumCode_(
        fourCharCode('Wrng'))
    error_kind = NSAppleEventDescriptor.descriptorWithEnumCode_(
        fourCharCode('Err '))

    # Accumulate the set of errors found on compiler output.
    entries = []
    for line in compilerOutput.splitlines():
        match = pat.match(line)
        if match:
            file, line, message = match.groups()
            kind = warning_kind if warning.match(message) else error_kind
            file = os.path.abspath(file)
            # BBEdit returns error -1701 for nonexistent files.
            if os.path.exists(file):
                entry = {
                  'result_kind': kind,
                  'result_file': file,
                  'result_line': int(line),
                  'message': message
                }
                entries.append(entry)
    return entries


def showResultsBrowser(name, entries):
    BBEdit = SBApplication.applicationWithBundleIdentifier_(
      "com.barebones.BBEdit")
    ResultsBrowser = BBEdit.classForScriptingClass_("results browser")
    properties = {'name': name}
    browserSpecifier = ResultsBrowser.alloc().initWithElementCode_properties_data_(
      fourCharCode('RslW'), properties, entries)
    BBEdit.windows().addObject_(browserSpecifier)

filePath = getFrontBBEditDocument()
print filePath
if filePath:
    compilerOutput = invokeClosureCompiler(filePath)
    entries = processMessages(compilerOutput)
    if entries:
        title = "Closure Compiler"
        showResultsBrowser(title, entries)


# MIT License
# 
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.