watchjs - Watch Javascript/CoffeeScript files for changes, concatenate and uglify

README.md

watchjs - Watch Javascript/CoffeeScript files for changes, concatenate and uglify

Just a very simple Python script (that depends on Node executables :p) to concatenate JS/Coffeescript files and compress them. I run a Procfile with Foreman that runs this python script on the js/ directory in small projects + stylus on the .styl files. It's similar to some functionality of Brunch.io but where Brunch is not suited I needed a small wrapper to do this for me.

Usage:

chmod +x watchjs.py

./watchjs.py <directory> <output filename>

Few notes: it concatenates files by filename, so it's best to prefix files with order numbers. Files that have the extension ".min.js" are not run through Uglify. You can uncomment lines in the code for Mac OS X, and the computer will announce verbally when there are errors in compilation.

Requirements:

Node's NPM: uglifyjs and coffee need to be in path

Python's PIP: envoy, clint

watchjs.py

#!/usr/bin/python
import os, time, sys
from functools import partial
import envoy
from clint.textui import puts, indent
from clint.textui.colored import red, green, cyan

def check_ext(filename, ext):
    if type(ext) is not list:
        ext = [ext]
    return filename.split(".")[-1] in ext

assert len(sys.argv) == 3, "Usage: watchjs <directory> <filename>"

path = sys.argv[1] + "/" if sys.argv[1][-1] != "/" else sys.argv[1]
name = sys.argv[2]
fullname = path+name
times = {}
just_compiled = False
first_loop = True

puts(cyan("Running watchjs"))
while True:
  changed = False
  files = filter(lambda x:partial(check_ext,ext=["js", "coffee"])(x) and x != name, os.listdir(path))
  files.sort()
  for f in files:
      if first_loop:
          puts(green("Watching "+f))
      modtime = os.stat(path+f).st_mtime
      if times.has_key(f) and times[f] != modtime and not just_compiled:
          puts(green("Changed: "+f))
          changed = True
      elif not times.has_key(f) and not first_loop:
          puts(green("Added: "+f))
          changed = True
      times[f] = modtime
  just_compiled = False
  if changed or first_loop:

    concatted = ""
    for f in files:
      source = ""
      if check_ext(f, "coffee"):
        cmd = envoy.run("coffee -p %s" % (path+f,))
        if cmd.std_err:
            puts(red("Error compiling %s:" % (path+f,)))
            with indent(4):
               puts(red(cmd.std_err))
            #Uncomment for Mac OS X
            #envoy.run("say 'o, no!'")
            concatted = ""
            break
        else:
            source = cmd.std_out
      else:
          source = open(path+f, "r").read()
      if f[-7:] == ".min.js":
          concatted += source
      else:
          uglified = envoy.run("uglifyjs", data=source)
          if uglified.std_err:
              puts(red("Error compiling %s:" % (path+f,)))
              with indent(4):
                 puts(red(uglified.std_err))
              #Uncomment for Mac OS X
              #envoy.run("say 'o, no!'")
              concatted = ""
              break
          else:
              concatted += uglified.std_out

    if concatted:
        output = open(fullname, "w")
        output.write(concatted)
        output.close()
        puts(green("Compiled to "+name))
    compiled = True

  first_loop = False
  time.sleep (1)