Emit a 'release' event when a connection is released back to the pool

packages/pg-pool/index.js

@@ -330,6 +330,8 @@ class Pool extends EventEmitter {
 
  client._poolUseCount = (client._poolUseCount || 0) + 1
 
+ this.emit('release', err, client)
+
  // TODO(bmc): expose a proper, public interface _queryable and _ending
  if (err || this.ending || !client._queryable || client._ending || client._poolUseCount >= this.options.maxUses) {
  if (client._poolUseCount >= this.options.maxUses) {

packages/pg-pool/test/events.js

@@ -60,6 +60,42 @@ 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 (err, client) {
+ expect(err instanceof Error).not.to.be(true)
+ expect(client).to.be.ok()
+ releaseCount++
+ })
+ for (let i = 0; i < 10; i++) {
+ pool.connect(function (err, client, release) {
+ if (err) return done(err)
+ release()
+ })
+ pool.query('SELECT now()')
+ }
+ setTimeout(function () {
+ expect(releaseCount).to.be(20)
+ pool.end(done)
+ }, 100)
+ })
+
+ it('emits release with an error if client is released due to an error', function (done) {
+ const pool = new Pool()
+ pool.connect(function (err, client, release) {
+ expect(err).to.equal(undefined)
+ const releaseError = new Error('problem')
+ pool.once('release', function (err, errClient) {
+ console.log(err, errClient)
+ expect(err).to.equal(releaseError)
+ expect(errClient).to.equal(client)
+ pool.end(done)
+ })
+ release(releaseError)
+ })
+ })
+
  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) {