fix(change-mail-task): Ignore 404s when changing mail so that we don't attempt to roll back and re-create purged objects + spec

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

@@ -287,6 +287,23 @@ describe "ChangeMailTask", ->
           advanceClock()
           expect(resolved).toBe(true)
 
+      it "should carry on and resolve if a request 404s, since the NylasAPI manager will clean the object from the cache", ->
+        promises = []
+        spyOn(NylasAPI, 'makeRequest').andCallFake ->
+          new Promise (resolve, reject) -> promises.push({resolve, reject})
+
+        resolved = false
+        runs ->
+          @task.performRequests(Thread, [@threadA, @threadB]).then =>
+            resolved = true
+        waitsFor ->
+          NylasAPI.makeRequest.callCount is 2
+        runs ->
+          promises[0].resolve()
+          promises[1].reject(new APIError(statusCode: 404))
+          advanceClock()
+          expect(resolved).toBe(true)
+
       it "should reject with the request error encountered by any request", ->
         promises = []
         spyOn(NylasAPI, 'makeRequest').andCallFake ->
@@ -309,7 +326,8 @@ describe "ChangeMailTask", ->
           expect(err).toBe(apiError)
 
       it "should use /threads when the klass provided is Thread", ->
-        spyOn(NylasAPI, 'makeRequest')
+        spyOn(NylasAPI, 'makeRequest').andCallFake ->
+          new Promise (resolve, reject) -> #noop
         runs ->
           @task.performRequests(Thread, [@threadA, @threadB])
         waitsFor ->
@@ -320,7 +338,8 @@ describe "ChangeMailTask", ->
           expect(NylasAPI.makeRequest.calls[0].args[0].accountId).toBe(@threadA.accountId)
 
       it "should use /messages when the klass provided is Message", ->
-        spyOn(NylasAPI, 'makeRequest')
+        spyOn(NylasAPI, 'makeRequest').andCallFake ->
+          new Promise (resolve, reject) -> #noop
         runs ->
           @task.performRequests(Message, [@threadAMesage1])
         waitsFor ->
@@ -331,7 +350,8 @@ describe "ChangeMailTask", ->
           expect(NylasAPI.makeRequest.calls[0].args[0].accountId).toBe(@threadAMesage1.accountId)
 
       it "should decrement change counts as requests complete", ->
-        spyOn(NylasAPI, 'makeRequest')
+        spyOn(NylasAPI, 'makeRequest').andCallFake ->
+          new Promise (resolve, reject) -> #noop
         spyOn(@task, '_removeLock')
         runs ->
           @task.performRequests(Message, [@threadAMesage1])

src/flux/nylas-api.coffee

@@ -322,7 +322,7 @@ class NylasAPI
 
     {create, modify, destroy}
 
-  _handleDeltaDeletion: (delta) ->
+  _handleDeltaDeletion: (delta) =>
     klass = @_apiObjectToClassMap[delta.object]
     return unless klass
     DatabaseStore.find(klass, delta.id).then (model) ->

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

@@ -148,6 +148,10 @@ class ChangeMailTask extends Task
         beforeProcessing: (body) =>
           @_removeLock(model)
           body
+      .catch (err) =>
+        if err instanceof APIError and err.statusCode is 404
+          return Promise.resolve()
+        Promise.reject(err)
 
   # Task lifecycle