feature(automatic-transactions): Creates a decorator to make transactions easier for the developer

add-handler.js

@@ -0,0 +1,12 @@
+module.exports = (existingHandler, newHandler) => {
+  if (Array.isArray(existingHandler)) {
+    return [
+      ...existingHandler,
+      newHandler
+    ]
+  } else if (typeof existingHandler === 'function') {
+    return [existingHandler, newHandler]
+  } else {
+    return [newHandler]
+  }
+}

index.js

@@ -3,6 +3,10 @@
 const defaultPg = require('pg')
 const fp = require('fastify-plugin')
 
+const addHandler = require('./add-handler.js')
+
+const transactionFailedSymbol = Symbol('transactionFailed')
+
 function transactionUtil (pool, fn, cb) {
   pool.connect((err, client, done) => {
     if (err) return cb(err)
@@ -52,6 +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
 
@@ -102,6 +110,59 @@ function fastifyPostgres (fastify, options, next) {
     }
   }
 
+  if (!fastify.hasRequestDecorator('pg')) {
+    fastify.decorateRequest('pg', null)
+  }
+
+  fastify.addHook('onRoute', routeOptions => {
+    const transactionConnection = routeOptions.pg && routeOptions.pg.transact
+
+    if (transactionConnection) {
+      const preHandler = async (req, reply) => {
+        const client = await pool.connect()
+
+        if (name) {
+          req.pg = {}
+          if (client[name]) {
+            throw new Error(`pg client '${name}' is a reserved keyword`)
+          } else if (req.pg[name]) {
+            throw new Error(`request client '${name}' has already been registered`)
+          }
+
+          req.pg[name] = client
+        } else {
+          if (req.pg) {
+            throw new Error('request client has already been registered')
+          } else {
+            req.pg = client
+          }
+        }
+
+        extractRequestClient(req, transactionConnection).query('BEGIN')
+      }
+
+      const onError = (req, reply, error, done) => {
+        req[transactionFailedSymbol] = true
+        extractRequestClient(req, transactionConnection).query('ROLLBACK', done)
+      }
+
+      const onSend = async (req) => {
+        const requestClient = extractRequestClient(req, transactionConnection)
+        try {
+          if (!req[transactionFailedSymbol]) {
+            await requestClient.query('COMMIT')
+          }
+        } finally {
+          requestClient.release()
+        }
+      }
+
+      routeOptions.preHandler = addHandler(routeOptions.preHandler, preHandler)
+      routeOptions.onError = addHandler(routeOptions.onError, onError)
+      routeOptions.onSend = addHandler(routeOptions.onSend, onSend)
+    }
+  })
+
   next()
 }
 

package.json

@@ -5,6 +5,7 @@
   "main": "index.js",
   "types": "index.d.ts",
   "scripts": {
+    "testonly": "tap -J test/*.test.js && npm run test:typescript",
     "test": "standard && tap -J test/*.test.js && npm run test:typescript",
     "test:typescript": "tsd",
     "test:report": "standard && tap -J --coverage-report=html test/*.test.js",

test/add-handler.test.js

@@ -0,0 +1,43 @@
+'use strict'
+
+const t = require('tap')
+const test = t.test
+const addHandler = require('../add-handler')
+
+test('addHandler - ', t => {
+  test('when existing handler is not defined', t => {
+    t.plan(1)
+
+    const handlers = addHandler(
+      undefined,
+      'test'
+    )
+
+    t.same(handlers, ['test'])
+  })
+  test('when existing handler is a array', t => {
+    t.plan(1)
+
+    const handlers = addHandler(
+      ['test'],
+      'again'
+    )
+
+    t.same(handlers, ['test', 'again'])
+  })
+  test('when existing handler is a function', t => {
+    t.plan(2)
+
+    const stub = () => 'test'
+
+    const handlers = addHandler(
+      stub,
+      'again'
+    )
+
+    t.same(handlers[0](), 'test')
+    t.same(handlers[1], 'again')
+  })
+
+  t.end()
+})

test/initialization.test.js

@@ -110,7 +110,7 @@ test('Should throw when trying to register multiple instances without giving a n
   })
 })
 
-test('Should not throw when registering a named instance and an unnamed instance)', (t) => {
+test('Should not throw when registering a named instance and an unnamed instance', (t) => {
   t.plan(1)
 
   const fastify = Fastify()
@@ -191,7 +191,7 @@ test('fastify.pg namespace should exist', (t) => {
   })
 })
 
-test('fastify.pg.test namespace should exist', (t) => {
+test('fastify.pg custom namespace should exist if a name is set', (t) => {
   t.plan(6)
 
   const fastify = Fastify()

test/query.test.js

@@ -4,6 +4,7 @@ const t = require('tap')
 const test = t.test
 const Fastify = require('fastify')
 const fastifyPostgres = require('../index')
+
 const {
   BAD_DB_NAME,
   connectionString,
@@ -134,7 +135,7 @@ test('When fastify.pg root namespace is used:', (t) => {
   t.end()
 })
 
-test('When fastify.pg.test namespace is used:', (t) => {
+test('When fastify.pg custom namespace is used:', (t) => {
   t.test('Should be able to connect and perform a query', (t) => {
     t.plan(4)
 

test/req-initialization.test.js

@@ -0,0 +1,119 @@
+'use strict'
+
+const t = require('tap')
+const test = t.test
+const Fastify = require('fastify')
+const fastifyPostgres = require('../index')
+const { connectionString } = require('./helpers')
+
+const extractUserCount = response => parseInt(JSON.parse(response.payload).rows[0].userCount)
+
+test('fastify postgress useTransaction route option - ', t => {
+  test('queries that succeed provided', async t => {
+    const fastify = Fastify()
+    t.teardown(() => fastify.close())
+
+    await fastify.register(fastifyPostgres, {
+      connectionString
+    })
+
+    await fastify.pg.query('TRUNCATE users')
+
+    await fastify.get('/count-users', async (req, reply) => {
+      const result = await fastify.pg.query('SELECT COUNT(*) AS "userCount" FROM users WHERE username=\'pass-opt-in\'')
+
+      reply.send(result)
+    })
+
+    await fastify.get('/pass', { pg: { transact: true } }, async (req, reply) => {
+      await req.pg.query('INSERT INTO users(username) VALUES($1) RETURNING id', ['pass-opt-in'])
+      await req.pg.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 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())
+
+    await fastify.register(fastifyPostgres, {
+      connectionString
+    })
+
+    await fastify.pg.query('TRUNCATE users')
+
+    await fastify.get('/count-users', async (req, reply) => {
+      const result = await fastify.pg.query('SELECT COUNT(*) AS "userCount" FROM users WHERE username=\'fail-opt-in\'')
+
+      reply.send(result)
+    })
+
+    await fastify.get('/fail', { pg: { transact: true } }, async (req, reply) => {
+      await req.pg.query('INSERT INTO users(username) VALUES($1) RETURNING id', ['fail-opt-in'])
+      await req.pg.query('INSERT INTO users(username) VALUES($1) RETURNING id', ['fail-opt-in'])
+      await req.pg.query('INSERT INTO nope(username) VALUES($1) RETURNING id', ['fail-opt-in'])
+      reply.send('complete')
+    })
+
+    await fastify.inject({
+      method: 'GET',
+      url: '/fail'
+    })
+
+    const response = await fastify.inject({
+      method: 'GET',
+      url: '/count-users'
+    })
+
+    t.is(extractUserCount(response), 0)
+  })
+
+  t.end()
+})