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command.coffee

The coffee utility. Handles command-line compilation of CoffeeScript into various forms: saved into .js files or printed to stdout, piped to JavaScript Lint or recompiled every time the source is saved, printed as a token stream or as the syntax tree, or launch an interactive REPL.

External dependencies.

fs             = require 'fs'
path           = require 'path'
helpers        = require './helpers'
optparse       = require './optparse'
CoffeeScript   = require './coffee-script'
{spawn, exec}  = require 'child_process'
{EventEmitter} = require 'events'

Allow CoffeeScript to emit Node.js events.

helpers.extend CoffeeScript, new EventEmitter

printLine = (line) -> process.stdout.write line + '\n'
printWarn = (line) -> process.stderr.write line + '\n'

The help banner that is printed when coffee is called without arguments.

BANNER = '''
  Usage: coffee [options] path/to/script.coffee

  If called without options, `coffee` will run your script.
         '''

The list of all the valid option flags that coffee knows how to handle.

SWITCHES = [
  ['-b', '--bare',            'compile without a top-level function wrapper']
  ['-c', '--compile',         'compile to JavaScript and save as .js files']
  ['-e', '--eval',            'pass a string from the command line as input']
  ['-h', '--help',            'display this help message']
  ['-i', '--interactive',     'run an interactive CoffeeScript REPL']
  ['-j', '--join [FILE]',     'concatenate the source CoffeeScript before compiling']
  ['-l', '--lint',            'pipe the compiled JavaScript through JavaScript Lint']
  ['-n', '--nodes',           'print out the parse tree that the parser produces']
  [      '--nodejs [ARGS]',   'pass options directly to the "node" binary']
  ['-o', '--output [DIR]',    'set the output directory for compiled JavaScript']
  ['-p', '--print',           'print out the compiled JavaScript']
  ['-r', '--require [FILE*]', 'require a library before executing your script']
  ['-s', '--stdio',           'listen for and compile scripts over stdio']
  ['-t', '--tokens',          'print out the tokens that the lexer/rewriter produce']
  ['-v', '--version',         'display the version number']
  ['-w', '--watch',           'watch scripts for changes and rerun commands']
]

Top-level objects shared by all the functions.

opts         = {}
sources      = []
sourceCode   = []
notSources   = {}
watchers     = {}
optionParser = null

Run coffee by parsing passed options and determining what action to take. Many flags cause us to divert before compiling anything. Flags passed after -- will be passed verbatim to your script as arguments in process.argv

exports.run = ->
  parseOptions()
  return forkNode()                      if opts.nodejs
  return usage()                         if opts.help
  return version()                       if opts.version
  loadRequires()                         if opts.require
  return require './repl'                if opts.interactive
  if opts.watch and !fs.watch
    printWarn "The --watch feature depends on Node v0.6.0+. You are running #{process.version}."
  return compileStdio()                  if opts.stdio
  return compileScript null, sources[0]  if opts.eval
  return require './repl'                unless sources.length
  if opts.run
    opts.literals = sources.splice(1).concat opts.literals
  process.argv = process.argv.slice(0, 2).concat opts.literals
  process.argv[0] = 'coffee'
  process.execPath = require.main.filename
  for source in sources
    compilePath source, yes, path.normalize source
    

Compile a path, which could be a script or a directory. If a directory is passed, recursively compile all '.coffee' extension source files in it and all subdirectories.

compilePath = (source, topLevel, base) ->
  path.exists source, (exists) ->
    if topLevel and not exists and source[-7..] isnt '.coffee'
      source = sources[sources.indexOf(source)] = "#{source}.coffee"
      return compilePath source, topLevel, base
    if topLevel and not exists 
      console.error "File not found: #{source}"
      process.exit 1
    fs.stat source, (err, stats) ->
      throw err if err
      if stats.isDirectory()
        watchDir source, base if opts.watch
        fs.readdir source, (err, files) ->
          throw err if err
          files = files.map (file) -> path.join source, file
          index = sources.indexOf source
          sources[index..index] = files
          sourceCode[index..index] = files.map -> null
          compilePath file, no, base for file in files
      else if topLevel or path.extname(source) is '.coffee'
        watch source, base if opts.watch
        fs.readFile source, (err, code) ->
          throw err if err
          compileScript(source, code.toString(), base)
      else
        notSources[source] = yes
        removeSource source, base
            

Compile a single source script, containing the given code, according to the requested options. If evaluating the script directly sets __filename, __dirname and module.filename to be correct relative to the script's path.

compileScript = (file, input, base) ->
  o = opts
  options = compileOptions file
  try
    t = task = {file, input, options}
    CoffeeScript.emit 'compile', task
    if      o.tokens      then printTokens CoffeeScript.tokens t.input
    else if o.nodes       then printLine CoffeeScript.nodes(t.input).toString().trim()
    else if o.run         then CoffeeScript.run t.input, t.options
    else if o.join and t.file isnt o.join
      sourceCode[sources.indexOf(t.file)] = t.input
      compileJoin()
    else
      t.output = CoffeeScript.compile t.input, t.options
      CoffeeScript.emit 'success', task
      if o.print          then printLine t.output.trim()
      else if o.compile   then writeJs t.file, t.output, base
      else if o.lint      then lint t.file, t.output
  catch err
    CoffeeScript.emit 'failure', err, task
    return if CoffeeScript.listeners('failure').length
    return printLine err.message if o.watch
    printWarn err instanceof Error and err.stack or "ERROR: #{err}"
    process.exit 1

Attach the appropriate listeners to compile scripts incoming over stdin, and write them back to stdout.

compileStdio = ->
  code = ''
  stdin = process.openStdin()
  stdin.on 'data', (buffer) ->
    code += buffer.toString() if buffer
  stdin.on 'end', ->
    compileScript null, code

If all of the source files are done being read, concatenate and compile them together.

compileJoin = ->
  return unless opts.join
  unless sourceCode.some((code) -> code is null)
    compileScript opts.join, sourceCode.join('\n'), opts.join

Load files that are to-be-required before compilation occurs.

loadRequires = ->
  realFilename = module.filename
  module.filename = '.'
  require req for req in opts.require
  module.filename = realFilename

Watch a source CoffeeScript file using fs.watch, recompiling it every time the file is updated. May be used in combination with other options, such as --lint or --print.

watch = (source, base) ->
  
  prevStats = null
  
  compile = ->
    fs.stat source, (err, stats) ->
      throw err if err
      return if prevStats and (stats.size is prevStats.size and
        stats.mtime.getTime() is prevStats.mtime.getTime())
      prevStats = stats
      fs.readFile source, (err, code) ->
        throw err if err
        compileScript(source, code.toString(), base)
      
  watcher = fs.watch source, callback = (event) ->
    if event is 'change'
      compile()
    else if event is 'rename'
      watcher.close()
      setTimeout -> 
        path.exists source, (exists) ->
          if exists
            compile()
            watcher = fs.watch source, callback
          else
            removeSource source, base, yes
            compileJoin()
      , 250
      

Watch a directory of files for new additions.

watchDir = (source, base) ->
  watcher = fs.watch source, ->
    path.exists source, (exists) ->
      if exists
        fs.readdir source, (err, files) ->
          throw err if err
          files = files.map (file) -> path.join source, file
          for file in files when not notSources[file] 
            continue if sources.some (s) -> s.indexOf(file) >= 0
            sources.push file
            sourceCode.push null
            compilePath file, no, base
      else
        watcher.close()
        toRemove = (file for file in sources when file.indexOf(source) >= 0)
        removeSource file, base, yes for file in toRemove
        compileJoin()
        

Remove a file from our source list, and source code cache. Optionally remove the compiled JS version as well.

removeSource = (source, base, removeJs) ->
  index = sources.indexOf source
  sources.splice index, 1
  sourceCode.splice index, 1
  if removeJs and not opts.join
    jsPath = outputPath source, base
    path.exists jsPath, (exists) ->
      if exists
        fs.unlink jsPath, (err) -> 
          throw err if err
          timeLog "removed #{source}"
        

Get the corresponding output JavaScript path for a source file.

outputPath = (source, base) ->
  filename  = path.basename(source, path.extname(source)) + '.js'
  srcDir    = path.dirname source
  baseDir   = if base is '.' then srcDir else srcDir.substring base.length
  dir       = if opts.output then path.join opts.output, baseDir else srcDir
  path.join dir, filename

Write out a JavaScript source file with the compiled code. By default, files are written out in cwd as .js files with the same name, but the output directory can be customized with --output.

writeJs = (source, js, base) ->
  jsPath = outputPath source, base
  jsDir  = path.dirname jsPath
  compile = ->
    js = ' ' if js.length <= 0
    fs.writeFile jsPath, js, (err) ->
      if err
        printLine err.message
      else if opts.compile and opts.watch
        timeLog "compiled #{source}"
  path.exists jsDir, (exists) ->
    if exists then compile() else exec "mkdir -p #{jsDir}", compile
    

When watching scripts, it's useful to log changes with the timestamp.

timeLog = (message) ->
  console.log "#{(new Date).toLocaleTimeString()} - #{message}"

Pipe compiled JS through JSLint (requires a working jsl command), printing any errors or warnings that arise.

lint = (file, js) ->
  printIt = (buffer) -> printLine file + ':\t' + buffer.toString().trim()
  conf = __dirname + '/../../extras/jsl.conf'
  jsl = spawn 'jsl', ['-nologo', '-stdin', '-conf', conf]
  jsl.stdout.on 'data', printIt
  jsl.stderr.on 'data', printIt
  jsl.stdin.write js
  jsl.stdin.end()

Pretty-print a stream of tokens.

printTokens = (tokens) ->
  strings = for token in tokens
    [tag, value] = [token[0], token[1].toString().replace(/\n/, '\\n')]
    "[#{tag} #{value}]"
  printLine strings.join(' ')

Use the OptionParser module to extract all options from process.argv that are specified in SWITCHES.

parseOptions = ->
  optionParser  = new optparse.OptionParser SWITCHES, BANNER
  o = opts      = optionParser.parse process.argv.slice 2
  o.compile     or=  !!o.output
  o.run         = not (o.compile or o.print or o.lint)
  o.print       = !!  (o.print or (o.eval or o.stdio and o.compile))
  sources       = o.arguments
  sourceCode[i] = null for source, i in sources
  return

The compile-time options to pass to the CoffeeScript compiler.

compileOptions = (filename) -> {filename, bare: opts.bare}

Start up a new Node.js instance with the arguments in --nodejs passed to the node binary, preserving the other options.

forkNode = ->
  nodeArgs = opts.nodejs.split /\s+/
  args     = process.argv[1..]
  args.splice args.indexOf('--nodejs'), 2
  spawn process.execPath, nodeArgs.concat(args),
    cwd:        process.cwd()
    env:        process.env
    customFds:  [0, 1, 2]

Print the --help usage message and exit. Deprecated switches are not shown.

usage = ->
  printLine (new optparse.OptionParser SWITCHES, BANNER).help()

Print the --version message and exit.

version = ->
  printLine "CoffeeScript version #{CoffeeScript.VERSION}"