Log all fs.write* operations with a stack trace in node.js

log-all-fs-writes.js

// Stick this in the top of your main app.js/server.js/whatever file.
// Any time one of the below fs.* methods are called anywher in the app or dependencies, 
// this code will log the details including the method, arguments, and a stack trace.
// It will then complete the write as normal.

var fs = require('fs');
['write','writeSync','writeFile','writeFileSync', 'appendFile', 'appendFileSync','createWriteStream'].forEach(function(fn){
	fs['real'+fn] = fs[fn]; 
	fs[fn] = function() {
		var e = new Error();
		console.log('fs.'+fn+' called with ' + Array.prototype.join.call(arguments, ', ') + ' Stack trace is:');
		console.log(e.stack.split('\n').slice(2).join('\n')); // slice out the empty error and reference to this wrapper
		return fs['real'+fn].apply(fs, arguments);
	};
	fs[fn].name = fn;
});

Note: this is now available in slightly-enhanced form as an npm module: https://www.npmjs.com/package/log-fs-writes