Merge pull request #19 from cemremengu/connection-scope

Feature: Execution scope (transact)

Author: cemremengu

README.md

@@ -131,6 +131,52 @@ fastify.get('/db_data', async function (req, reply) {
 
 If needed `pool` instance can be accessed via `fastify.oracle[.dbname].pool`
 
+## Use of scoped executions
+
+```js
+const fastify = require('fastify')
+
+fastify.register(require('fastify-oracle'), {
+  pool: {
+    user: 'travis',
+    password: 'travis',
+    connectString: 'localhost/xe'
+  } 
+})
+
+fastify.post('/user/:username', (req, reply) => {
+  // will return a promise, fastify will send the result automatically
+  return fastify.oracle.scope(async conn => {
+    // will resolve to commit, or reject with an error
+    return conn.execute(`INSERT INTO USERS (NAME) VALUES('JIMMY')`)
+  })
+})
+
+/* or with a scope callback
+
+fastify.oracle.scope(conn => {
+    return conn.execute('SELECT * FROM DUAL')
+  },
+  function onResult (err, result) {
+    reply.send(err || result)
+  }
+})
+
+*/
+
+/* or with a commit callback
+
+fastify.oracle.scope((conn, commit) => {
+  conn.execute('SELECT * FROM DUAL', (err, res) => {
+    commit(err, res)
+  });
+})
+
+*/
+
+```
+
+
 ## License
 
 [MIT License](http://jsumners.mit-license.org/)

package.json

@@ -4,7 +4,7 @@
   "description": "A plugin for Fastify to provide Oracle DB connections",
   "main": "plugin.js",
   "scripts": {
-    "test": "standard && tap --cov test.js",
+    "test": "standard && tap --cov test/*.test.js",
     "lint": "standard | snazzy"
   },
   "precommit": [

plugin.js

@@ -3,10 +3,51 @@
 const fp = require('fastify-plugin')
 const oracledb = require('oracledb')
 
+function transactScope (pool, fn, cb) {
+  pool.getConnection(function (err, conn) {
+    if (err) return cb(err)
+
+    const commit = (err, res) => {
+      if (err) return conn.close(() => cb(err))
+
+      conn.commit(function (err) {
+        conn.close(function () {
+          if (err) {
+            return cb(err)
+          }
+          return cb(null, res)
+        })
+      })
+    }
+
+    const promise = fn(conn, commit)
+
+    if (promise && typeof promise.then === 'function') {
+      promise.then(
+        (res) => commit(null, res),
+        (e) => commit(e))
+    }
+  })
+}
+
+function transact (fn, cb) {
+  if (cb && typeof cb === 'function') {
+    return transactScope(this, fn, cb)
+  }
+
+  return new Promise((resolve, reject) => {
+    transactScope(this, fn, function (err, res) {
+      if (err) { return reject(err) }
+      return resolve(res)
+    })
+  })
+}
+
 function decorateFastifyInstance (pool, fastify, options, next) {
   const oracle = {
     getConnection: pool.getConnection.bind(pool),
-    pool
+    pool,
+    transact: transact.bind(pool)
   }
 
   if (options.name) {