Compare different eval's in node.js

f1.js

module.exports = function(data) {
    var s = '';
    s += '<div class="hello">';
    s += 'Hello, ' + data.username;
    s += '</div>';
    return s;
};

f2.js

function(data) {
    var s = '';
    s += '<div class="hello">';
    s += 'Hello, ' + data.username;
    s += '</div>';
    return s;
}

make.sh

#!/bin/bash

echo 'require'
node test-require.js
echo 'function'
node test-function.js
echo 'vm'
node test-vm.js
echo 'eval'
node test-eval.js

test-eval.js

var fs = require('fs');

var js = fs.readFileSync('f2.js', 'utf-8');

var f = eval('(' + js + ')');

var data = {
    username: 'nop'
};

console.time('a');
for (var i = 0; i < 10000000; i++) {
    var r = f(data);
}
console.timeEnd('a');

test-function.js

var fs = require('fs');

var js = fs.readFileSync('f2.js', 'utf-8');

var f = ( new Function('global', '"use strict"; return (' + js + ')') )();

var data = {
    username: 'nop'
};

console.time('a');
for (var i = 0; i < 10000000; i++) {
    var r = f(data);
}
console.timeEnd('a');

test-require.js

var f = require('./f1.js');

var data = {
    username: 'nop'
};

console.time('a');
for (var i = 0; i < 10000000; i++) {
    var r = f(data);
}
console.timeEnd('a');

test-vm.js

var fs = require('fs');
var vm = require('vm');

var js = fs.readFileSync('f2.js', 'utf-8');

var f = vm.runInNewContext('(' + js + ')');

var data = {
    username: 'nop'
};

console.time('a');
for (var i = 0; i < 10000000; i++) {
    var r = f(data);
}
console.timeEnd('a');

Потому что eval не джитится. Равно как и runInNewContext видимо.