Unit testing two Mobile Services scripts that encrypt on insert and decrypt on read.

items.insert.js

// the insert script that encrypts the text column
var crypto = require('crypto');
 
function insert(item, user, request) {
    // your encryption key - choose something better and randomly generated in real-life
    var password = 'zumoisawesome'
    var cipher = crypto.createCipher('aes256', password);
    var output = cipher.update(item.text, 'utf-8', 'base64');
    item.text = output + cipher.final('base64');
    // go ahead, insert the modified data
    request.execute();
}

items.read.js

// the read script that decrypts the text column
var crypto = require('crypto');
 
function read(query, user, request) {
    // your encryption key - choose something better and randomly generated in real-life
    var password = 'zumoisawesome'
    // go ahead and fetch the data, but invoke my success function 
    // and I'll respond to the device
    request.execute({
        success: function(results) {   
            // for each item in the result set
            results.forEach(function(row) {
                // decrypt the text column
                var decipher = crypto.createDecipher('aes256', password);
                var output = decipher.update(row.text, 'base64', 'binary');
                output += decipher.final('binary');
                row.text = new Buffer(output, 'binary').toString('utf-8');
            });
            // send the response to the device
            request.respond();
        }  
    });
}

test.js

// we need the assert module for testing
var assert = require('assert');
// we need the fs module to load the scripts from disk (assuming in ./table folder)
var fs = require('fs');

// suite of tests for my 'items' table
suite('items', function() {
  // test to ensure data is encrypted before it hits the disk
  test('should encrypt data on insert', function(done) {
  		// load the insert script
		eval(fs.readFileSync('./table/items.insert.js', 'utf8'));
		
		// create an item with text to be encrypted
		var item = { text : "boo" };
		
		// create the mock request object
		var request = { 
			// and the mock execute function
			execute : function() {
				// assertion
				assert.notEqual("boo", item.text);
				// test complete
				done();
			}
		}
		// kick off the test by using the loaded insert method
		insert(item, null, request);
	});

	// test to ensure that an insert followed by read yields the original value
	test('insert followed by read should return same value', function(done) {
		// load the insert and read scripts
		eval(fs.readFileSync('./table/items.insert.js', 'utf8'));
		eval(fs.readFileSync('./table/items.read.js', 'utf8'));
		
		// create a fake item with text to be encrypted
		var item = { text : "boo" };
		
		// the request object passed to insert
		var insertRequest = { 
			// and mock execute
			execute : function() {
				// assert our text is encrypted
				assert.notEqual(item.text, "boo");
				// after insert call the read function
				read(null, null, readRequest);
			}
		}
		
		// the request object passed to read
		var readRequest = {
			// specify the mock execute function of request
			execute: function(options) {
				// call success, to go back into the script
				// as though we've just loaded 
				options.success([item]);
			},
			// create the mock respond function
			respond: function() {
				// assert that our text is now decrypted
				assert.equal(item.text, "boo");
				// test is over
				done();
			}
		}
		
		// kick off the flow
		insert(item, null, insertRequest);
	});
});