How to parse a query to remove null statements

[maxrahder]

I'm very new to elasticsearch.

I'm working on a UI that lets users compose queries by dragging UI widgets around. Sometimes they end up trying to run a search without having provided arguments, and the resulting search is logically empty. Is there a library or technique for taking a query and returning a new query with empty elements removed?

Here are a couple of examples of what our UI produces (based on user interaction). I believe those are both null queries. If there's not something built in, or some library for cleaning those up, is there a lexer/parser API that lets me process the query so I can clean it up myself?

    {
        "query": {
            "bool": {
                "must": [{
                    "bool": {
                        "must": [{
                            "bool": {
                                "must": []
                            }
                        }, {
                            "has_child": {
                                "type": "foo",
                                "query": {
                                    "bool": {
                                        "filter": [{
                                            "range": {
                                                "foo.date": {
                                                    "query": "",
                                                    "operator": "and"
                                                }
                                            }
                                        }]
                                    }
                                }
                            }
                        }]
                    }
                }]
            }
        }
    }

And here's another one:

    {
        "query": {
            "bool": {
                "must": [{
                    "bool": {
                        "must": [{
                            "bool": {
                                "must": []
                            }
                        }]
                    }
                }]
            }
        }
    }