fixing the bug report - #152

[kamiljano]

fixing: https://github.com/yeahoffline/redis-mock/issues/152

[isRyven]

Thanks for looking into it, but better not to use or operator for this case, for instance these cases will return wrong result (null), while the values are being perfectly valid:

0 || null // null
"" || null // null

best way to check if key actually exists is using the in operator or object.hasOwnProperty(key):

if (mockInstance.storage[hash].value.hasOwnProperty(key)) {
    return mockInstance.storage[hash].value[key];
}
return null;

[kamiljano]

well that is a fair point. I'll fix it

[kamiljano]

et voilla