关闭JavaScript中承诺的连接的最干净的方法是什么

Question

Using NodeJS, MongoDb.

MongoClient returns a promise which is really nice, but I am not sure if I am using it correctly. What is the cleanest way to do something like:

const mongo = require('mongodb').MongoClient;
return mongo
         .connect(getConnectionString())
         .then(con => {
              func1(con)
              .then(val => {return func2(con, val);})
              .then(val => {con.close(); return val;})
              .catch(err => log.error(err));
          });

 //contrived func to get my point across
 func1(connection) {
     //use connection to fetch data
     return fetchedData;         
 }

 //contrived func to get my point across
 func2(connection, val) {
     //use connection to fetch data
     return fetchedData + val;         
 }

You see how I have create a scope for the connection so that I can close it with func1 & func2 are done. Is there a cleaner approach?

If there is a cleaner way to invoke func1 & funct2 I'd appreciate that as well.

Answer 1

I would use Bluebird's .using

Example straight from their API documentation

using(getConnection(), function(connection) {
   // Don't leak the `connection` variable anywhere from here
   // it is only guaranteed to be open while the promise returned from
   // this callback is still pending
   return connection.queryAsync("SELECT * FROM TABLE");
   // Code that is chained from the promise created in the line above
   // still has access to `connection`
}).then(function(rows) {
    // The connection has been closed by now
    console.log(rows);
});