Fix listen reconnect on connection errors + simple backoff

Author: porsager

lib/connection.js

@@ -352,13 +352,15 @@ function postgresSocket(options, {
   let next = null
   let buffer
   let i = 0
+  let retries = 0
 
   function onclose(err) {
+    retries++
     oncleanup()
     !ended && !succeeded && i < options.host.length
       ? connect()
       : err instanceof Error
-        ? error(err)
+        ? (error(err), close())
         : close()
     i >= options.host.length && (i = 0)
   }
@@ -373,10 +375,14 @@ function postgresSocket(options, {
     cleanup()
   }
 
-  function connect() {
+  async function connect() {
     if (!closed)
       return
 
+    retries && await new Promise(r =>
+      setTimeout(r, Math.min((0.5 + Math.random()) * Math.pow(1.3, retries) * 10, 10000))
+    )
+
     closed = succeeded = false
 
     socket = options.path
@@ -419,6 +425,7 @@ function postgresSocket(options, {
   }
 
   function ready() {
+    retries = 0
     try {
       socket.write(frontend.StartupMessage(options))
     } catch (e) {
@@ -429,6 +436,7 @@ function postgresSocket(options, {
 
   const x = {
     success: () => {
+      retries = 0
       succeeded = true
       i >= options.host.length && (i = 0)
     },

tests/index.js

@@ -574,12 +574,19 @@ t('listen and notify with weird name', async() => {
   )]
 })
 
-t('listen and notify with upper case', async() =>
-  ['works', await new Promise(async resolve => {
-    await sql.listen('withUpperChar', resolve)
-    sql.notify('withUpperChar', 'works')
-  })]
-)
+t('listen and notify with upper case', async() => {
+  let result
+
+  const { unlisten } = await sql.listen('withUpperChar', x => result = x)
+  sql.notify('withUpperChar', 'works')
+  await delay(50)
+
+  return [
+    'works',
+    result,
+    unlisten()
+  ]
+})
 
 t('listen reconnects', async() => {
   const listener = postgres(options)
@@ -596,6 +603,29 @@ t('listen reconnects', async() => {
   return ['ab', xs.join('')]
 })
 
+
+t('listen reconnects after connection error', { timeout: 2000 }, async() => {
+  const sql = postgres()
+      , xs = []
+
+  const a = (await sql`show data_directory`)[0].data_directory
+
+  const { state: { pid } } = await sql.listen('test', x => xs.push(x))
+  await sql.notify('test', 'a')
+  await sql`select pg_terminate_backend(${ pid }::int)`
+
+  cp.execSync('pg_ctl stop -D "' + a + '"')
+  await delay(50)
+  cp.execSync('pg_ctl start -D "' + a + '" -w -l "' + a + '/postgresql.log"')
+  await delay(50)
+
+  await sql.notify('test', 'b')
+  await delay(50)
+  sql.end()
+
+  return ['ab', xs.join('')]
+})
+
 t('listen result reports correct connection state after reconnection', async() => {
   const listener = postgres(options)
       , xs = []