Add callback interface to pool#query (#11)

* Add callback interface to pool#query

* Fix linting errors

index.js

@@ -83,13 +83,16 @@ Pool.prototype.connect = function (cb) {
 
 Pool.prototype.take = Pool.prototype.connect
 
-Pool.prototype.query = function (text, values) {
+Pool.prototype.query = function (text, values, cb) {
   return new this.Promise(function (resolve, reject) {
     this.connect(function (err, client, done) {
       if (err) return reject(err)
       client.query(text, values, function (err, res) {
         done(err)
         err ? reject(err) : resolve(res)
+        if (cb) {
+          cb(err, res)
+        }
       })
     })
   }.bind(this))

test/index.js

@@ -32,6 +32,16 @@ describe('pool', function () {
       })
     })
 
+    it('can run a query with a callback', function (done) {
+      const pool = new Pool()
+      pool.query('SELECT $1::text as name', ['brianc'], function (err, res) {
+        expect(res.rows[0]).to.eql({ name: 'brianc' })
+        pool.end(function () {
+          done(err)
+        })
+      })
+    })
+
     it('removes client if it errors in background', function (done) {
       const pool = new Pool()
       pool.connect(function (err, client, release) {