From c4fe23307e6fee1deca6da5c878dd00bade35957 Mon Sep 17 00:00:00 2001
From: Natalie Wolfe <natalie@lifewanted.com>
Date: Fri, 15 Dec 2017 14:20:54 -0800
Subject: [PATCH 1/3] Use class-extends to wrap Pool

---
 lib/index.js | 33 ++++++++++++++++-----------------
 1 file changed, 16 insertions(+), 17 deletions(-)

diff --git a/lib/index.js b/lib/index.js
index 00e3ceed4..9b92d94f7 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -7,31 +7,30 @@
  * README.md file in the root directory of this source tree.
  */
 
-var util = require('util')
 var Client = require('./client')
 var defaults = require('./defaults')
 var Connection = require('./connection')
 var Pool = require('pg-pool')
 
-const poolFactory = (Client) => {
-  var BoundPool = function (options) {
-    var config = Object.assign({ Client: Client }, options)
-    return new Pool(config)
+const poolFactory = (pg) => {
+  return class BoundPool extends Pool {
+    constructor (options) {
+      var config = Object.assign({ Client: pg.Client }, options)
+      super(config)
+    }
   }
-
-  util.inherits(BoundPool, Pool)
-
-  return BoundPool
 }
 
-var PG = function (clientConstructor) {
-  this.defaults = defaults
-  this.Client = clientConstructor
-  this.Query = this.Client.Query
-  this.Pool = poolFactory(this.Client)
-  this._pools = []
-  this.Connection = Connection
-  this.types = require('pg-types')
+class PG {
+  constructor (clientConstructor) {
+    this.defaults = defaults
+    this.Client = clientConstructor
+    this.Query = this.Client.Query
+    this.Pool = poolFactory(this)
+    this._pools = []
+    this.Connection = Connection
+    this.types = require('pg-types')
+  }
 }
 
 if (typeof process.env.NODE_PG_FORCE_NATIVE !== 'undefined') {

From da590fae514115713b6b11bbdcfae3a6dab1bc1a Mon Sep 17 00:00:00 2001
From: Charmander <~@charmander.me>
Date: Wed, 15 Jan 2020 12:18:46 -0800
Subject: [PATCH 2/3] Minimize diff

---
 packages/pg/lib/index.js | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/packages/pg/lib/index.js b/packages/pg/lib/index.js
index 113bf685e..c3062947d 100644
--- a/packages/pg/lib/index.js
+++ b/packages/pg/lib/index.js
@@ -12,25 +12,23 @@ var defaults = require('./defaults')
 var Connection = require('./connection')
 var Pool = require('pg-pool')
 
-const poolFactory = (pg) => {
+const poolFactory = (Client) => {
   return class BoundPool extends Pool {
     constructor (options) {
-      var config = Object.assign({ Client: pg.Client }, options)
+      var config = Object.assign({ Client: Client }, options)
       super(config)
     }
   }
 }
 
-class PG {
-  constructor (clientConstructor) {
-    this.defaults = defaults
-    this.Client = clientConstructor
-    this.Query = this.Client.Query
-    this.Pool = poolFactory(this)
-    this._pools = []
-    this.Connection = Connection
-    this.types = require('pg-types')
-  }
+var PG = function (clientConstructor) {
+  this.defaults = defaults
+  this.Client = clientConstructor
+  this.Query = this.Client.Query
+  this.Pool = poolFactory(this.Client)
+  this._pools = []
+  this.Connection = Connection
+  this.types = require('pg-types')
 }
 
 if (typeof process.env.NODE_PG_FORCE_NATIVE !== 'undefined') {

From 5fa8a4937c15f9c51707e49431c29aa4f5e319ec Mon Sep 17 00:00:00 2001
From: "Brian M. Carlson" <brian.m.carlson@gmail.com>
Date: Fri, 10 Jan 2020 09:57:21 -0600
Subject: [PATCH 3/3] Test `BoundPool` inheritance

---
 .../test/integration/gh-issues/1542-tests.js  | 25 +++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 packages/pg/test/integration/gh-issues/1542-tests.js

diff --git a/packages/pg/test/integration/gh-issues/1542-tests.js b/packages/pg/test/integration/gh-issues/1542-tests.js
new file mode 100644
index 000000000..4d30d6020
--- /dev/null
+++ b/packages/pg/test/integration/gh-issues/1542-tests.js
@@ -0,0 +1,25 @@
+
+"use strict"
+const helper = require('./../test-helper')
+const assert = require('assert')
+
+const suite = new helper.Suite()
+
+suite.testAsync('BoundPool can be subclassed', async () => {
+  const Pool = helper.pg.Pool;
+  class SubPool extends Pool {
+
+  }
+  const subPool = new SubPool()
+  const client = await subPool.connect()
+  client.release()
+  await subPool.end()
+  assert(subPool instanceof helper.pg.Pool)
+})
+
+suite.test('calling pg.Pool without new throws', () => {
+  const Pool = helper.pg.Pool;
+  assert.throws(() => {
+    const pool = Pool()
+  })
+})