feat: Add fixed interval retry to requests

lib/send.js

@@ -1,9 +1,24 @@
+'use strict'
+
 const https = require('https')
 const http = require('http')
 const concat = require('concat-stream')
 const url = require('url')
+const MAX_ATTEMPTS = 5
+const RETRY_INTERVAL = process.env.BUGSNAG_RETRY_INTERVAL || 1000
 
 module.exports = (endpoint, data, onSuccess, onError) => {
+  let attempts = 0
+  const maybeRetry = (err) => {
+    attempts++
+    if (err && err.isRetryable && attempts < MAX_ATTEMPTS) return setTimeout(go, RETRY_INTERVAL)
+    return onError(err)
+  }
+  const go = () => send(endpoint, data, onSuccess, maybeRetry)
+  go()
+}
+
+const send = (endpoint, data, onSuccess, onError) => {
   const parsedUrl = url.parse(endpoint)
   const payload = JSON.stringify(data)
   const req = (parsedUrl.protocol === 'https:' ? https : http).request({
@@ -19,7 +34,9 @@ module.exports = (endpoint, data, onSuccess, onError) => {
     res.pipe(concat(body => {
       if (res.statusCode === 200) return onSuccess()
       if (res.statusCode !== 400) {
-        return onError(new Error(`HTTP status ${res.statusCode} received from builds API`))
+        const err = new Error(`HTTP status ${res.statusCode} received from builds API`)
+        err.isRetryable = true
+        return onError(err)
       }
       try {
         const err = new Error('Invalid payload sent to builds API')

lib/test/send.test.js

@@ -1,5 +1,7 @@
 'use strict'
 
+process.env.BUGSNAG_RETRY_INTERVAL = 50
+
 const test = require('tape')
 const http = require('http')
 const send = require('../send')
@@ -48,6 +50,29 @@ test('send(): unsuccessful (500)', t => {
   })
 })
 
+test('send(): retry (500)', t => {
+  t.plan(1)
+  let n = 0
+  const server = http.createServer((req, res) => {
+    n++
+    if (n < 4) {
+      res.statusCode = 500
+      return res.end('error')
+    } else {
+      return res.end('ok')
+    }
+  })
+  server.listen()
+  send(`http://localhost:${server.address().port}`, {}, () => {
+    server.close()
+    t.equal(n, 4, 'it should make multiple attempts')
+    t.end()
+  }, (err) => {
+    server.close()
+    t.end(err)
+  })
+})
+
 test('send(): unsuccessful (400)', t => {
   t.plan(3)
   const server = http.createServer((req, res) => {
@@ -68,6 +93,29 @@ test('send(): unsuccessful (400)', t => {
   })
 })
 
+test('send(): unsuccessful, doesn’t retry (400)', t => {
+  t.plan(4)
+  let n = 0
+  const server = http.createServer((req, res) => {
+    n++
+    res.statusCode = 400
+    res.setHeader('content-type', 'application/json')
+    res.end('{ "errors": [ "flipflop is not a valid crankworble" ] }')
+  })
+  server.listen()
+  send(`http://localhost:${server.address().port}`, {}, () => {
+    server.close()
+    t.fail('send should not succeed')
+  }, (err) => {
+    server.close()
+    t.ok(err)
+    t.equal(n, 1, 'It should never retry a bad request')
+    t.equal(err.message, 'Invalid payload sent to builds API')
+    t.deepEqual(err.errors, [ 'flipflop is not a valid crankworble' ])
+    t.end()
+  })
+})
+
 test('send(): unsuccessful (400, bad json)', t => {
   t.plan(2)
   const server = http.createServer((req, res) => {