test(pg): add temporary backend termination probe for brianc#3772

Author: devtechedge

packages/pg/test/integration/gh-issues/3772-tests.js

@@ -0,0 +1,56 @@
+'use strict'
+
+const helper = require('./../test-helper')
+const assert = require('assert')
+
+const suite = new helper.Suite()
+
+suite.test('real PostgreSQL backend termination after Sync surfaces connection failure', function (done) {
+  const client = new helper.Client({ pipeline: true })
+  const killer = new helper.Client()
+  let finished = false
+  let timer
+
+  const finish = function (err) {
+    if (finished) return
+    finished = true
+    clearTimeout(timer)
+    killer.end(() => client.end(() => done(err)))
+  }
+
+  client.on('error', function (err) {
+    assert(err instanceof Error)
+    finish()
+  })
+
+  client.on('end', function () {
+    if (!finished) finish()
+  })
+
+  client.connect(function (err) {
+    if (err) return done(err)
+
+    client.query('SELECT pg_backend_pid() AS pid', function (err, result) {
+      if (err) return done(err)
+      const pid = result.rows[0].pid
+
+      // Force the extended-query protocol, which sends Sync after the query.
+      client.query({
+        text: 'SELECT $1::int AS value',
+        values: [1],
+      })
+
+      killer.connect(function (err) {
+        if (err) return done(err)
+        killer.query('SELECT pg_terminate_backend($1)', [pid], function (err, result) {
+          if (err) return done(err)
+          assert.equal(result.rows[0].pg_terminate_backend, true)
+        })
+      })
+    })
+  })
+
+  timer = setTimeout(function () {
+    finish(new Error('timed out waiting for PostgreSQL connection termination'))
+  }, 2000)
+})