compile-ejs.js

#!/usr/bin/env node

// =================================================================================
// Copyright (c) 2014 sheutettz. All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
// 
//   1. Redistributions of source code must retain the above copyright notice, this
//      list of conditions and the following disclaimer.
// 
//   2. Redistributions in binary form must reproduce the above copyright notice,
//      this list of conditions and the following disclaimer in the documentation
//      and/or other materials provided with the distribution.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
// IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
// INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
// OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
// OF THE POSSIBILITY OF SUCH DAMAGE.
// =================================================================================

'use strict';

var _ = require('lodash');
var fs = require('fs');
var path = require('path');
var glob = require('glob');
var ejs = require('ejs');
var uglifyjs = require('uglify-js');

var args = process.argv.slice(2);
var production = (process.env.npm_config_production === 'true');
var minify = false;
var distclean = false;
var filePatterns = [];

args.forEach(function (val, index, array) {
  if (val === '--minify') {
    minify = true;
  }
  else if (val === '--no-minify') {
    minify = false;
  }
  else if (val === '--production') {
    production = true;
  }
  else if (val === '--no-production') {
    production = false;
  }
  else if (val === '--distclean') {
    distclean = true;
  }
  else if (_.isString(val) && val.length > 0) {
    if (val.match(/^-+[a-zA-Z0-9][-a-zA-Z0-9]*$/)) {
      console.warn('unknown command line option: ' + val);
    }
    else {
      filePatterns.push(val);
    }
  }
});

if (filePatterns.length === 0) {
  console.error('Error! No filename patterns specified!\n');
  console.log('Usage: ejs-compiler.js [options] filename-patterns [filename-patterns ...]');
  console.log('[Options]');
  console.log('  --minify       : enable minified compilation.');
  console.log('  --no-minify    : disable minified compilation.');
  console.log('  --distclean    : does not compile and generate the target js file(s) but removes instead.');
  console.log('  --production   : enable optimized compilation.');
  console.log('  --no-production: disable optimized compilation.');
  console.log();
}

var action = distclean ? unlinkFile : compileFile;
_.each(filePatterns, function (filename) {
  glob(filename, {}, function (er, files) {
    if (er) {
      console.error(er);
      return;
    }
    _.each(files, action);
  });
});

function unlinkFile(srcFile) {
  var dstFile = changeExt(srcFile, '.js');
  if (fs.existsSync(srcFile) && fs.existsSync(dstFile)) {
    console.warn('remove ' + dstFile);
    fs.unlinkSync(dstFile);
  }
}

function compileFile(srcFile) {

  var src = fs.readFileSync(srcFile, 'utf8');
  if (!src) {
    console.error("failed to read file: " + srcFile);
    return;
  }

  var opts = {
    client: true,
    compileDebug: !production,
    filename: srcFile
  };
  var fn = ejs.compile(src, opts);
  if (!_.isFunction(fn)) {
    console.error("failed to compile: " + srcFile);
    return;
  }

  var js = "module.exports = " + fn.toString();
  {
    js = uglifyjs.minify(js, {
      fromString: true,
      output: {
        beautify: !minify
      },
      beautify: {
        bracketize: true
      },
      mangle: {
        toplevel: true,
        eval: minify
      },
      compress: {
        unsafe: false,
        evaluate: true,
        conditionals: true,
        booleans: true,
        if_return: true,
        sequences: minify,
        join_vars: minify,
        dead_code: production,
        drop_debugger: production,
        unused: production,
        drop_console: production
      }
    }).code;
  }

  var dstFile = changeExt(srcFile, '.js');
  fs.writeFileSync(dstFile, js, 'utf8');
}

function changeExt(filename, newExt) {
  var ext = path.extname(filename);
  if (_.isString(ext) && ext.length > 0) {
    var len = filename.length - ext.length;
    return filename.substr(0, len) + newExt;
  } else {
    return filename + newExt;
  }
}