uglify.js

#!/usr/local/bin/node

// BBEdit text filter to uglify Javascript.
// Uses the default compression options, *except* it turns off warnings because they cause the script to error out.
// 
// Requires uglifyjs https://github.com/mishoo/UglifyJS2
// In this example, I've installed uglifyjs globally via `npm install uglify-js -g`
// Your install directory may be different...

var UglifyJS = require('/usr/local/share/npm/lib/node_modules/uglify-js');
var chunks = "";

process.stdin.resume();
process.stdin.setEncoding('utf8');

process.stdin.on('data', function(chunk) {
    chunks += chunk;
});

process.stdin.on('end', function() {
    var options = {
        fromString: true,
        compress: {
            // defaults here: http://lisperator.net/uglifyjs/compress
            sequences     : true,  // join consecutive statemets with the “comma operator”
            properties    : true,  // optimize property access: a["foo"] → a.foo
            dead_code     : true,  // discard unreachable code
            drop_debugger : true,  // discard “debugger” statements
            unsafe        : false, // some unsafe optimizations (see below)
            conditionals  : true,  // optimize if-s and conditional expressions
            comparisons   : true,  // optimize comparisons
            evaluate      : true,  // evaluate constant expressions
            booleans      : true,  // optimize boolean expressions
            loops         : true,  // optimize loops
            unused        : true,  // drop unused variables/functions
            hoist_funs    : true,  // hoist function declarations
            hoist_vars    : false, // hoist variable declarations
            if_return     : true,  // optimize if-s followed by return/continue
            join_vars     : true,  // join var declarations
            cascade       : true,  // try to cascade `right` into `left` in sequences
            side_effects  : true,  // drop side-effect-free statements
            warnings      : false, // warn about potentially dangerous optimizations/code -- turned this off or script errors out
            global_defs   : {}     // global definitions
        },
        mangle: true
    };
    var out = UglifyJS.minify(chunks, options);
    
    process.stdout.write(out.code);
});