From b8457bb921dd0c40698f40ae6bb24335f05960a3 Mon Sep 17 00:00:00 2001
From: Petteri Sulonen <sulonen@avain.intra>
Date: Mon, 20 May 2019 12:57:23 +0300
Subject: [PATCH 1/2] Implement 'release' event and 'activeCount' property.
 https://github.com/brianc/node-pg-pool/issues/124

---
 index.js       | 13 ++++++++++---
 test/events.js | 21 +++++++++++++++++++++
 2 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/index.js b/index.js
index cfe377c..b4525f0 100644
--- a/index.js
+++ b/index.js
@@ -44,8 +44,9 @@ function release (client, err) {
       this._remove(client)
     }, this.options.idleTimeoutMillis)
   }
-
   this._idle.push(new IdleItem(client, tid))
+  this._active.splice(this._active.indexOf(client, 1))
+  this.emit('release', client)
   this._pulseQueue()
 }
 
@@ -94,6 +95,7 @@ class Pool extends EventEmitter {
 
     this._clients = []
     this._idle = []
+    this._active = []
     this._pendingQueue = []
     this._endCallback = undefined
     this.ending = false
@@ -149,8 +151,8 @@ class Pool extends EventEmitter {
 
   _remove (client) {
     const removed = removeWhere(
-      this._idle,
-      item => item.client === client
+    this._idle,
+    item => item.client === client
     )
 
     if (removed !== undefined) {
@@ -250,6 +252,7 @@ class Pool extends EventEmitter {
       } else {
         this.log('new client connected')
         client.release = release.bind(this, client)
+        this._active.push(client)
         this.emit('connect', client)
         this.emit('acquire', client)
         if (!pendingItem.timedOut) {
@@ -328,5 +331,9 @@ class Pool extends EventEmitter {
   get totalCount () {
     return this._clients.length
   }
+
+  get activeCount () {
+    return this._active.length
+  }
 }
 module.exports = Pool
diff --git a/test/events.js b/test/events.js
index a2da481..421d06b 100644
--- a/test/events.js
+++ b/test/events.js
@@ -60,6 +60,27 @@ describe('events', function () {
     }, 100)
   })
 
+  it('emits release every time a client is released', function (done) {
+    const pool = new Pool()
+    let releaseCount = 0
+    pool.on('release', function (client) {
+      expect(client).to.be.ok()
+      releaseCount++
+    })
+    for (let i = 0; i < 10; i++) {
+      pool.connect(function (err, client, release) {
+        if (err) return done(err)
+        expect(pool.activeCount).to.be.greaterThan(0)
+        setTimeout(release, 1)
+      })
+    }
+    setTimeout(function () {
+      expect(releaseCount).to.be(10)
+      expect(pool.activeCount).to.be(0)
+      pool.end(done)
+    }, 100)
+  })
+
   it('emits error and client if an idle client in the pool hits an error', function (done) {
     const pool = new Pool()
     pool.connect(function (err, client) {

From 8b5d49f4e70c7f1216420cc494533c1ddaed91bc Mon Sep 17 00:00:00 2001
From: Petteri Sulonen <sulonen@avain.intra>
Date: Tue, 21 May 2019 08:10:47 +0300
Subject: [PATCH 2/2] Fix bug erroneously truncating ._active array and improve
 test case to fully test .activeCount property.
 https://github.com/brianc/node-pg-pool/issues/124

---
 index.js       | 6 +++---
 test/events.js | 9 ++++++---
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/index.js b/index.js
index b4525f0..7789bb5 100644
--- a/index.js
+++ b/index.js
@@ -45,7 +45,7 @@ function release (client, err) {
     }, this.options.idleTimeoutMillis)
   }
   this._idle.push(new IdleItem(client, tid))
-  this._active.splice(this._active.indexOf(client, 1))
+  this._active.splice(this._active.indexOf(client), 1)
   this.emit('release', client)
   this._pulseQueue()
 }
@@ -151,8 +151,8 @@ class Pool extends EventEmitter {
 
   _remove (client) {
     const removed = removeWhere(
-    this._idle,
-    item => item.client === client
+      this._idle,
+      item => item.client === client
     )
 
     if (removed !== undefined) {
diff --git a/test/events.js b/test/events.js
index 421d06b..82b1e0d 100644
--- a/test/events.js
+++ b/test/events.js
@@ -67,11 +67,14 @@ describe('events', function () {
       expect(client).to.be.ok()
       releaseCount++
     })
-    for (let i = 0; i < 10; i++) {
+    for (let releases = [], i = 0; i < 10; i++) {
       pool.connect(function (err, client, release) {
         if (err) return done(err)
-        expect(pool.activeCount).to.be.greaterThan(0)
-        setTimeout(release, 1)
+        releases.push(release)
+        expect(pool.activeCount).to.be(releases.length)
+        if (releases.length === 10) {
+          while (releases.length > 0) releases.pop()()
+        }
       })
     }
     setTimeout(function () {