Get the "signature" of an IndexedDB database. Hopefully this becomes useful to those who are trying to circumvent versioning.

getIDBSignature.js

function getIDBSignature(name,callback) {
  var request = window.indexedDB.open(name);
  request.onsuccess = function(event) {
    var x,db = event.target.result;
    var objectStore,objectStores = [];
    for(x = 0;x < db.objectStoreNames.length;x++) {
      objectStores.push(db.objectStoreNames.item(x));
    }
    var transaction = db.transaction(objectStores, "readonly");
    objectStores = objectStores.map(function(objectStoreName) {
      var objectStore = transaction.objectStore(objectStoreName);
      console.log(objectStore);
      var indexNames = [];
      for(var x = 0;x < objectStore.indexNames.length;x++) {
        indexNames.push(objectStore.indexNames.item(x));
      }
      return {
        autoIncrement: objectStore.autoIncrement,
        indexNames: indexNames,
        keyPath: objectStore.keyPath,
        name: objectStore.name
      };
    });
    callback({
      name: db.name,
      objectStores: objectStores,
      version: db.version
    });
    db.close(name);
  };
}