[local-sync] Account for additional IMAP retryable errors

Summary:
There are 2 types of IMAP errors that need to be treated as retryable. See code
comments as to why.

Test Plan: manual

Reviewers: khamidou, evan, spang

Reviewed By: spang

Differential Revision: https://phab.nylas.com/D3811

packages/isomorphic-core/src/imap-errors.js

@@ -76,6 +76,21 @@ class IMAPCertificateError extends NylasError { }
  */
 function convertImapError(imapError) {
   let error;
+
+  if (imapError.message.includes('System Error')) {
+    // System Errors encountered in the wild so far have been retryable.
+    error = new RetryableError(imapError)
+    error.source = imapError.source
+    return error
+  }
+  if (imapError.message.includes('User is authenticated but not connected')) {
+    // We need to treat this type of error as retryable
+    // See https://github.com/mscdex/node-imap/issues/523 for more details
+    error = new IMAPSocketError(imapError)
+    error.source = imapError.source
+    return error
+  }
+
   switch (imapError.source) {
     case "socket-timeout":
       error = new IMAPConnectionTimeoutError(imapError); break;

packages/local-sync/src/local-sync-worker/sync-process-manager.js

@@ -5,6 +5,7 @@ const {Actions} = require('nylas-exports')
 const SyncWorker = require('./sync-worker');
 const LocalDatabaseConnector = require('../shared/local-database-connector')
 
+
 class SyncProcessManager {
   constructor() {
     this._workers = {};