gulp-closurizer

closure compiler plugin for gulp.

getting started

Make sure that you have a copy of the closure compiler jar file accessible to your project. By default the plugin will look for:

PROJECT_HOME/closure/compiler.jar

Install the plugin with

npm install gulp-closurizer --save-dev

example gulp setup

var gulp      = require('gulp'),
    compiler  = require('gulp-closure');

gulp.task('compile' function() {

  gulp.src('src/**/*.js')
  .pipe(compiler())
  .pipe(gulp.dest('/output'));
});

You can pass a plethora of configuration options to the plugin via a configuration object passed at config time.

var gulp      = require('gulp'),
    glob      = require('glob'),
    compiler  = require('gulp-closure')({
      plugin    : {
        compiler                 : 'closure/build/compiler.jar',
        maxBuffer                : 1024 * 1024 * 20
      },
      compiler  : {
        '--angular_pass'         : null,
        '--compilation_level'    : 'ADVANCED_OPTIMIZATIONS',
        '--externs'              : glob.sync('closure/externs/**/*.jsx')
      },
      java      : {
        '-XX:+TieredCompilation' : null
      }
    });

gulp.task('compile' function() {

  gulp.src('src/**/*.js')
  .pipe(compiler)
  .pipe(gulp.dest('/output'));
});

options

The options object contains 3 sub-objects: plugin, compiler and java.

The plugin object change the behaviour of the plugin itself:

• sourcePass this option is a boolean which determines whether the source files should be passed through to the output with the compiled js. Useful when dealing with sourcemaps. Default is false
• mapComment this option is a boolean which determines whether a //# sourceMappingURL= comment should be added to the end of your compiled js. This option defaults to true but does nothing if the --create_source_map compiler option isn't set.
• compiler this option is a string which is the relative path to the compiler jar.
• flagfile this option is the name of the flagfile that will be generated by the plugin. You shouldn't need to change this unless the default ('flagfile.tmp') clashes with any of the other temporary files that will be created during compilation.
• output this option sets the name of the output file that will be passed back to the gulp stream. Default is output.min.js
• maxBuffer this option sets the maxBuffer options for the process that node creates. Default is 1024 * 1024 * 20

The compiler object is serialized into the flags to be passed to the compiler, By default we don't pass any options that aren't required to the compiler.

• The keys of the objecct will map directly to the flag name created.
• If you want to create a flag which has no value, simply set its value to null

example

compiler : {
  '--angular_pass' : null,
  '--compilation_level' : 'ADVANCED_OPTIMIZATIONS'
}

Will become

--angular_pass --compilation_level="ADVANCED_OPTIMIZATIONS"

There are some options that are not supported currently by the plugin, these are:

• --module
• --flag_file
• --js_output_file

For more information see source code.

The java object is used to set options for the java instance used to run the compiler. This object is serialized in the same way that the compiler object is.

example

java : {
  '-XX:+TieredCompilation' : null
}

Sourcemaps

Sourcemaps are awesome!

Basic sourcemap example:

var gulp = require('gulp'),
    compiler = require('gulp-closurizer')({
        plugin : {
            mapComment : true,
            sourcePass : true
        },
        compiler: {
            '--create_source_map' : 'source.map'
        }
    });
    
gulp.task('compile', function() {

    gulp.src('src/**/*.js')
    .pipe(compiler)
    .pipe(gulp.dest('output'));
});

In this example the output folder will contain the source.map file, the compiled js file, and the uncompiled source files. The compiled js will also have a comment appended to the bottom which will link it with the soucemap file.

It's good to bear in mind that the source js files must be available on the server where your sourcemap is hosted. We output the soucemap with relative paths to the files by default.

TODO

• Come up with some kind of solution for creating modules.
• Possibly use --js_output_file instead of stdout to save files, as this may cause issues.
• Possibly do something with the compiler warning/error output.