fix(focused-persepective): Init saved perspective correctly

- When accounts changed and the saved perspective could reference
  accounts that no longer exist and cause all sorts of errors. This is
  fixed.
- Add specs
- Fixes some sentry errors

spec/stores/focused-perspective-store-spec.coffee

@@ -25,6 +25,35 @@ describe "FocusedPerspectiveStore", ->
       return @userCategory if id is @userCategory.id
       return null
 
+  describe "_initCurrentPerspective", ->
+    beforeEach ->
+      @default = 'default'
+      @accounts = [{id: 1}, {id: 2}]
+      spyOn(MailboxPerspective, 'fromJSON').andCallFake (json) -> json
+      spyOn(FocusedPerspectiveStore, '_defaultPerspective').andReturn @default
+
+    it "uses default perspective when no perspective has been saved", ->
+      current = FocusedPerspectiveStore._initCurrentPerspective(undefined, @accounts)
+      expect(current).toEqual @default
+
+    it "uses default if saved perspective has more account ids not present in current accounts", ->
+      saved = {accountIds: [1,2,3]}
+      current = FocusedPerspectiveStore._initCurrentPerspective(saved, @accounts)
+      expect(current).toEqual @default
+
+      saved = {accountIds: [3]}
+      current = FocusedPerspectiveStore._initCurrentPerspective(saved, @accounts)
+      expect(current).toEqual @default
+
+    it "uses saved perspective if all accounts in saved perspective are present in the current accounts", ->
+      saved = {accountIds: [1,2]}
+      current = FocusedPerspectiveStore._initCurrentPerspective(saved, @accounts)
+      expect(current).toEqual saved
+
+      saved = {accountIds: [1]}
+      current = FocusedPerspectiveStore._initCurrentPerspective(saved, @accounts)
+      expect(current).toEqual saved
+
   describe "_onCategoryStoreChanged", ->
     it "should set the current category to Inbox when it is unset", ->
       FocusedPerspectiveStore._perspective = null

src/flux/stores/focused-perspective-store.coffee

@@ -7,14 +7,23 @@ Actions = require '../actions'
 
 class FocusedPerspectiveStore extends NylasStore
   constructor: ->
-    if NylasEnv.savedState.perspective
-      @_current = MailboxPerspective.fromJSON(NylasEnv.savedState.perspective)
-    @_current ?= @_defaultPerspective()
+    @_current = @_initCurrentPerspective(NylasEnv.savedState.perspective)
 
     @listenTo CategoryStore, @_onCategoryStoreChanged
     @listenTo Actions.focusMailboxPerspective, @_onFocusPerspective
     @listenTo Actions.focusDefaultMailboxPerspectiveForAccounts, @_onFocusAccounts
 
+  _initCurrentPerspective: (savedPerspective, accounts = AccountStore.accounts()) =>
+    if savedPerspective
+      current = MailboxPerspective.fromJSON(savedPerspective)
+      if current
+        accountIds = _.pluck(accounts, 'id')
+        accountIdsNotPresent = _.difference(current.accountIds, accountIds)
+        current = null if accountIdsNotPresent.length > 0
+
+    current ?= @_defaultPerspective()
+    return current
+
   # Inbound Events
 
   _onCategoryStoreChanged: ->