Allows namespacing on request

As with the base fastify instance, the pg decoration will use namespaces. For each namespaced called to the main function, the namespace will be added to the req.pg object too, with similar checks
The option to use a chosen namespace with the routeOptions is provided and we make sure that this namespace is used to extract the correct client from req.pg
A test also covers this for queries wrapped in a route transaction

Resolves #75

Author: Toni Sharpe

index.js

@@ -56,6 +56,10 @@ function transact (fn, cb) {
   })
 }
 
+function extractRequestClient (req, connectionId) {
+  return connectionId.length ? req.pg[connectionId] : req.pg
+}
+
 function fastifyPostgres (fastify, options, next) {
   let pg = defaultPg
 
@@ -111,13 +115,14 @@ function fastifyPostgres (fastify, options, next) {
   }
 
   fastify.addHook('onRoute', routeOptions => {
-    const useTransaction = routeOptions.pg && routeOptions.pg.transact
+    const transactionConnection = routeOptions.pg && routeOptions.pg.transact
 
-    if (useTransaction) {
+    if (transactionConnection) {
       const preHandler = async (req, reply) => {
         const client = await pool.connect()
 
         if (name) {
+          req.pg = {}
           if (client[name]) {
             throw new Error(`pg client '${name}' is a reserved keyword`)
           } else if (req.pg[name]) {
@@ -133,21 +138,22 @@ function fastifyPostgres (fastify, options, next) {
           }
         }
 
-        name ? req.pg[name].query('BEGIN') : req.pg.query('BEGIN')
+        extractRequestClient(req, transactionConnection).query('BEGIN')
       }
 
       const onError = (req, reply, error, done) => {
         req[transactionFailedSymbol] = true
-        name ? req.pg[name].query('ROLLBACK', done) : req.pg.query('ROLLBACK', done)
+        extractRequestClient(req, transactionConnection).query('ROLLBACK', done)
       }
 
       const onSend = async (req) => {
+        const requestClient = extractRequestClient(req, transactionConnection)
         try {
           if (!req[transactionFailedSymbol]) {
-            await name ? req.pg[name].query('COMMIT') : req.pg.query('COMMIT')
+            await requestClient.query('COMMIT')
           }
         } finally {
-          name ? req.pg[name].release() : req.pg.release()
+          requestClient.release()
         }
       }
 

test/req-initialization.test.js

@@ -43,6 +43,42 @@ test('fastify postgress useTransaction route option - ', t => {
 
     t.is(extractUserCount(response), 2)
   })
+  test('queries that succeed provided to a namespace', async t => {
+    const fastify = Fastify()
+    t.teardown(() => fastify.close())
+
+    await fastify.register(fastifyPostgres, {
+      connectionString,
+      name: 'test'
+    })
+
+    await fastify.pg.test.query('TRUNCATE users')
+
+    await fastify.get('/count-users', async (req, reply) => {
+      const result = await fastify.pg.test.query('SELECT COUNT(*) AS "userCount" FROM users WHERE username=\'pass-opt-in\'')
+
+      reply.send(result)
+    })
+
+    await fastify.get('/pass', { pg: { transact: 'test' } }, async (req, reply) => {
+      await req.pg.test.query('INSERT INTO users(username) VALUES($1) RETURNING id', ['pass-opt-in'])
+      await req.pg.test.query('INSERT INTO users(username) VALUES($1) RETURNING id', ['pass-opt-in'])
+
+      reply.send('complete')
+    })
+
+    await fastify.inject({
+      method: 'GET',
+      url: '/pass'
+    })
+
+    const response = await fastify.inject({
+      method: 'GET',
+      url: '/count-users'
+    })
+
+    t.is(extractUserCount(response), 2)
+  })
   test('queries that fail provided', async t => {
     const fastify = Fastify()
     t.teardown(() => fastify.close())