File Dependencies

I have a questions about dependencies. Having the following object:

var files = {
    "f": {"dep": ["b", "c"]},
    "g": {"dep": ["e", "f"]},
    "a": {"dep": ["c", "b"]},
    "b": {"dep": ["d", "c"]},
    "c": {"dep": []},
    "d": {"dep": ["c"]},
    "e": {"dep": ["a"]}
};

Need a way to create a sequence of all files(letters) in a way, that i will not messed up the dependency order of the files ( f will not come before b and c ). So my idea is to traverse it like i would do graph crawling.

//TODO -o :if we have e.g "a" depend on "b" and "b" depend on "a" this will lead to
//TODO -o :infinite recursion - so we should handle this scenario.

//Todo -o :It could be optimized by checking if the file is already visited.
//stores all files in dependant order
var filesInDependantOrder = [];

//loop through all files
for (var file in files)
{
    //call the drillDownDependencies to drill down to all files
    drillDownDependencies( files[file] );

    //we exit from the recursion drillDownDependencies and add the file that we have passed
    //if not exists
    if (filesInDependantOrder.indexOf( file ) < 0) {
        filesInDependantOrder.push( file );
    }
}

function drillDownDependencies( root )
{
    //loop through all dependencies of the given file
    for (var i = 0, ilen = root["dep"].length; i < ilen; i++)
    {
        //pass the dependency to check if the given
        //dependency has dependencies by its own
        drillDownDependencies( files[root["dep"][i]] );

        //we exit from the recursion if the dependency
        //don't have other dependencies
        if (filesInDependantOrder.indexOf( root["dep"][i] ) < 0)
        {
            //push the dependency that don't have
            //other dependencies if not exists
            filesInDependantOrder.push( root["dep"][i] );
        }
    }
}

console.log(filesInDependantOrder);

So the question is: Is my solution perfect? Would it fail in somehow having file, before dependency file?