checkIndexes.js

function checkDatabase(dbName) {
  var database = db.getSisterDB(dbName);
  database.getCollectionNames().forEach(function(colName){checkCollection(database, colName)});
};

function checkCollection(database, colName) {
  database.getCollection(colName).getIndexes().forEach(function(indexDoc){
    if(indexDoc.unique) {
      if (Object.keys(indexDoc.key).length > 1) {
        printjson("Cannot check compound indexe for uniqness. Sorry...");
        return;
      }
      var fieldName = indexDoc.name.substr(0, indexDoc.name.indexOf('_'));
      checkUniqueIndexIsUnique(database, colName, fieldName);
    }
  })
};

db.adminCommand({listDatabases: 1}).databases.forEach(function(dbDoc){checkDatabase(dbDoc.name)});