mem2.js

var ChildProcess = require('child_process');

var maxMem = Math.round(process.memoryUsage().rss / (1024 * 1024)) * 2;
console.time('leak');

setInterval(function () {

    ChildProcess.exec('echo', function () {

        var mem = Math.round(process.memoryUsage().rss / (1024 * 1024));

        console.log(mem + 'M used');
        if (mem >= maxMem) {
            console.log('Memory has doubled since process started');
            console.timeEnd('leak');
            process.exit();
        }
    });
}, 100);


/*
Output:

12M used
12M used
12M used
.
.
.
21M used
22M used
Memory has doubled since process started
leak: 52601ms
*/