Empty strings not written to SimpleDb

[aarong]

When using putItem or batchPutItem empty strings are not written to SDB. These writes do not seem to be included in the API request, maybe because "" == false somewhere.

To replicate:

var SimpleDb = require('simpledb');

var sdb = new SimpleDb.SimpleDB({
    keyid:      'keyid',
    secret:     'secret'
});

var fPutGet = function (inItemName, inValue) {

    // Write the item to SDB and read it back
    sdb.putItem(
        'testDomain',
        inItemName,
        { 'someAttribute': inValue },
        function (inError, inResult, inMeta) {

            console.log('putItem done (' + inItemName + ':' + inValue + '), error:', inError);

            sdb.getItem(
                'testDomain',
                inItemName,
                function (inError, inResult, inMeta) {

                    console.log('getItem done (' + inItemName + ':' + inValue + '), result:', inResult);

                }
            );

        }
    );

}

sdb.createDomain(
    'testDomain',
    function () {

        console.log('createDomain done');
        fPutGet('item1', 'not empty');
        fPutGet('item2', '');

    }
);

[aarong]

Also I just noticed that if you force a putItem API request to write an empty string using an override argument like this:

{
            'Attribute.0.Name': 'someAttribute',
            'Attribute.0.Value': '',
            'Attribute.0.Replace': "true"
}

and then read back the attribute using getItem, you get "[object Object]" as the value for the attribute. To replicate:

var SimpleDb = require('simpledb');

var sdb = new SimpleDb.SimpleDB({
    keyid:      'keyid',
    secret:     'secret'
});


var fPutGet = function (inItemName, inValue) {

    // Write the item to SDB and read it back
    sdb.putItem(
        'testDomain',
        inItemName,
        {},
        {
            'Attribute.0.Name': 'someAttribute',
            'Attribute.0.Value': inValue,
            'Attribute.0.Replace': "true"
        },
        function (inError, inResult, inMeta) {

            console.log('putItem done (' + inItemName + ':' + inValue + '), error:', inError);

            sdb.getItem(
                'testDomain',
                inItemName,
                function (inError, inResult, inMeta) {

                    console.log('getItem done (' + inItemName + ':' + inValue + '), result:', inResult);

                }
            );

        }
    );

}

sdb.createDomain(
    'testDomain',
    function () {

        console.log('createDomain done');
        fPutGet('item1', 'not empty');
        fPutGet('item2', '');

    }
);