Add support to stream factory (brianc#2898)

This changeset enables declaring the `stream` config value as a factory method. Providing a much more flexible control of the socket connection. Defining a custom `stream` config value allows the postgres driver to support a larger variety of environments/setups such as proxy servers and secure socket connections that are used by cloud providers such as GCP. Currently, usage of the `stream` config value is only viable for single connections given that it's only possible to define a single socket stream instance per new Client/Pool instance. By adding support to a factory function, it becomes possible to enable usage of custom socket streams for connection pools. For reference, see the `mysql2` driver for MySQL (linked below) for prior art example of this pattern. Refs: https://github.com/sidorares/node-mysql2/blob/ba15fe25703665e516ab0a23af8d828d1473b8c3/lib/connection.js#L63-L65 Refs: https://cloud.google.com/sql/docs/postgres/connect-overview Signed-off-by: Ruy Adorno <ruyadorno@google.com> Signed-off-by: Ruy Adorno <ruyadorno@google.com>

Author: ruyadorno

packages/pg/lib/connection.js

@@ -14,7 +14,12 @@ class Connection extends EventEmitter {
  constructor(config) {
  super()
  config = config || {}
+
  this.stream = config.stream || new net.Socket()
+ if (typeof this.stream === 'function') {
+ this.stream = this.stream(config)
+ }
+
  this._keepAlive = config.keepAlive
  this._keepAliveInitialDelayMillis = config.keepAliveInitialDelayMillis
  this.lastBuffer = false

packages/pg/test/unit/connection/startup-tests.js

@@ -7,6 +7,18 @@ test('connection can take existing stream', function () {
  assert.equal(con.stream, stream)
 })
 
+test('connection can take stream factory method', function () {
+ var stream = new MemoryStream()
+ var connectionOpts = {}
+ var makeStream = function (opts) {
+ assert.equal(connectionOpts, opts)
+ return stream
+ }
+ connectionOpts.stream = makeStream
+ var con = new Connection(connectionOpts)
+ assert.equal(con.stream, stream)
+})
+
 test('using any stream', function () {
  var makeStream = function () {
  var stream = new MemoryStream()