Keep trying to scale if deployment is not yet ready (#701)

* Keep on polling now-scale when deployment is not ready

* Use `ms`

lib/index.js

@@ -14,9 +14,9 @@ const retry = require('async-retry')
 const splitArray = require('split-array')
 const { parse: parseIni } = require('ini')
 const { readFile, stat, lstat } = require('fs-extra')
-const { responseError } = require('./error')
+const ms = require('ms')
 
-// Ours
+// Utilities
 const {
   staticFiles: getFiles,
   npm: getNpmFiles,
@@ -26,6 +26,7 @@ const ua = require('./ua')
 const hash = require('./hash')
 const Agent = require('./agent')
 const toHost = require('./to-host')
+const { responseError } = require('./error')
 
 // How many concurrent HTTP/2 stream uploads
 const MAX_CONCURRENT = 10
@@ -918,17 +919,21 @@ module.exports = class Now extends EventEmitter {
   }
 
   setScale(nameOrId, scale) {
-    return this.retry(async (bail, attempt) => {
+    return this.retry(
+      async (bail, attempt) => {
         if (this._debug) {
           console.time(
             `> [debug] #${attempt} POST /deployments/${nameOrId}/instances`
           )
         }
 
-      const res = await this._fetch(`/now/deployments/${nameOrId}/instances`, {
+        const res = await this._fetch(
+          `/now/deployments/${nameOrId}/instances`,
+          {
             method: 'POST',
             body: scale
-      })
+          }
+        )
 
         if (this._debug) {
           console.timeEnd(
@@ -944,6 +949,14 @@ module.exports = class Now extends EventEmitter {
 
         if (res.status !== 200) {
           if (res.status === 404 || res.status === 400) {
+            if (
+              body &&
+              body.error &&
+              body.error.code &&
+              body.error.code === 'not_snapshotted'
+            ) {
+              throw new Error(body.error.message)
+            }
             const err = new Error(body.error.message)
             err.userError = true
             return bail(err)
@@ -954,11 +967,19 @@ module.exports = class Now extends EventEmitter {
             err.userError = true
             return bail(err)
           }
-        throw new Error(`Error occurred while scaling. Please try again later`)
+          throw new Error(
+            `Error occurred while scaling. Please try again later`
+          )
         }
 
         return body
-    })
+      },
+      {
+        retries: 300,
+        maxTimeout: ms('5s'),
+        factor: 1.1
+      }
+    )
   }
 
   async unfreeze(depl) {