fix(tasks) ChangeMailTask should depend on EnsureMessagesInSentFolder

Summary:
See title
Add specs

Test Plan: unit

Reviewers: halla, evan

Reviewed By: halla, evan

Differential Revision: https://phab.nylas.com/D3805

spec/tasks/change-mail-task-spec.coffee

@@ -12,7 +12,9 @@ _ = require 'underscore'
  DatabaseTransaction,
  Task,
  Utils,
- ChangeMailTask} = require 'nylas-exports'
+ ChangeMailTask,
+ EnsureMessageInSentFolderTask,
+} = require 'nylas-exports'
 
 xdescribe "ChangeMailTask", ->
   beforeEach ->
@@ -552,6 +554,26 @@ xdescribe "ChangeMailTask", ->
       expect( -> task.createUndoTask()).toThrow()
 
   describe "isDependentOnTask", ->
+    it "should return true if another EnsureMessageInSentFolderTask involves one of the ChangeMailTask's threads", ->
+      a = new ChangeMailTask()
+      a.threads = ['t1', 't2', 't3']
+      s1 = new EnsureMessageInSentFolderTask({message: {threadId: 't1'}})
+      s2 = new EnsureMessageInSentFolderTask({message: {threadId: 't100'}})
+      expect(a.isDependentOnTask(s1)).toEqual(true)
+      expect(a.isDependentOnTask(s2)).toEqual(false)
+
+    it "should return true if another EnsureMessageInSentFolderTask involves one of the ChangeMailTask's messages", ->
+      a = new ChangeMailTask()
+      a.messages = ['m1', 'm2', 'm3']
+      s1 = new EnsureMessageInSentFolderTask({message: {clientId: 'm1'}})
+      s2 = new EnsureMessageInSentFolderTask({message: {serverId: 'm1'}})
+      s3 = new EnsureMessageInSentFolderTask({message: {clientId: 'm100'}})
+      s4 = new EnsureMessageInSentFolderTask({message: {serverId: 'm100'}})
+      expect(a.isDependentOnTask(s1)).toEqual(true)
+      expect(a.isDependentOnTask(s2)).toEqual(true)
+      expect(a.isDependentOnTask(s3)).toEqual(false)
+      expect(a.isDependentOnTask(s4)).toEqual(false)
+
     it "should return true if another, older ChangeMailTask involves the same threads", ->
       a = new ChangeMailTask()
       a.threads = ['t1', 't2', 't3']

src/flux/tasks/change-mail-task.es6

@@ -6,6 +6,7 @@ import NylasAPI from '../nylas-api';
 import SyncbackTaskAPIRequest from '../syncback-task-api-request';
 import DatabaseStore from '../stores/database-store';
 import {APIError} from '../errors';
+import EnsureMessageInSentFolderTask from './ensure-message-in-sent-folder-task'
 
 /*
 Public: The ChangeMailTask is a base class for all tasks that modify sets
@@ -307,6 +308,17 @@ export default class ChangeMailTask extends Task {
   // and removals need to be applied in order. (For example, star many threads,
   // and then unstar one.)
   isDependentOnTask(other) {
+    // Wait on EnsureMessageInSentFolderTask if it involves a message that
+    // belongs to a thread we are trying to operate on
+    if (other instanceof EnsureMessageInSentFolderTask && other.message) {
+      const objectIds = this.objectIds()
+      if (objectIds.includes(other.message.threadId)) {
+        return true;
+      }
+      if (objectIds.includes(other.message.clientId) || objectIds.includes(other.message.serverId)) {
+        return true;
+      }
+    }
     // Only wait on other tasks that are older and also involve the same threads
     if (!(other instanceof ChangeMailTask)) {
       return false;