fix(category): Consolidate logic around "archive" vs" all"

internal_packages/thread-list/lib/thread-list.cjsx

@@ -110,7 +110,6 @@ class ThreadList extends React.Component
           attachment = <div className="thread-icon thread-icon-attachment"></div>
 
         currentCategoryId = FocusedMailViewStore.mailView()?.categoryId()
-        allCategoryId = CategoryStore.getStandardCategory('all')?.id
 
         ignoredIds = [currentCategoryId]
         ignoredIds.push(cat.id) for cat in CategoryStore.getHiddenCategories()
@@ -265,7 +264,7 @@ class ThreadList extends React.Component
     return unless ThreadListStore.view()
 
     focused = FocusedContentStore.focused('thread')
-      
+
     if WorkspaceStore.layoutMode() is "list" and WorkspaceStore.topSheet() is WorkspaceStore.Sheet.Thread
       threads = [focused]
     else if ThreadListStore.view().selection.count() > 0

src/flux/models/account.coffee

@@ -53,24 +53,29 @@ class Account extends Model
       name: @name
       email: @emailAddress
 
-  # Public: The current organization_unit used by the account.
-  usesLabels: -> @organizationUnit is "label"
-  usesFolders: -> @organizationUnit is "folder"
+  usesLabels: ->
+    @organizationUnit is "label"
+
+  usesFolders: ->
+    @organizationUnit is "folder"
 
   categoryClass: ->
     if @usesLabels()
       return require './label'
-    else
+    else if @usesFolders()
       return require './folder'
+    else
+      return null
 
   # Public: Returns the localized, properly capitalized provider name,
   # like Gmail, Exchange, or Outlook 365
   displayProvider: ->
     if @provider is 'eas'
       return 'Exchange'
-    if @provider is 'gmail'
+    else if @provider is 'gmail'
       return 'Gmail'
-    return @provider
+    else
+      return @provider
 
   usesImportantFlag: ->
     @provider is 'gmail'

src/flux/stores/category-store.coffee

@@ -58,17 +58,15 @@ class CategoryStore extends NylasStore
       return "Folders"
     else if account.usesLabels()
       return "Labels"
-    return "Unknown"
+    else
+      return "Unknown"
 
+  # Public: Returns {Folder} or {Label}, depending on the current provider.
+  #
   categoryClass: ->
     account = AccountStore.current()
     return null unless account
-
-    if account.usesFolders()
-      return Folder
-    else if account.usesLabels()
-      return Label
-    return null
+    return account.categoryClass()
 
   # Public: Returns an array of all the categories in the current account, both
   # standard and user generated. The items returned by this function will be
@@ -85,6 +83,24 @@ class CategoryStore extends NylasStore
       throw new Error("'#{name}' is not a standard category")
     return _.findWhere @_categoryCache, {name}
 
+  # Public: Returns the Folder or Label object that should be used for "Archive"
+  # actions. On Gmail, this is the "all" label. On providers using folders, it
+  # returns any available "Archive" folder, or null if no such folder exists.
+  #
+  getArchiveCategory: ->
+    account = AccountStore.current()
+    return null unless account
+    if account.usesFolders()
+      return @getStandardCategory("archive")
+    else
+      return @getStandardCategory("all")
+
+  # Public: Returns the Folder or Label object taht should be used for
+  # "Move to Trash", or null if no trash folder exists.
+  #
+  getTrashCategory: ->
+    @getStandardCategory("trash")
+
   # Public: Returns all of the standard categories for the current account.
   #
   getStandardCategories: ->

src/flux/tasks/task-factory.coffee

@@ -46,19 +46,19 @@ class TaskFactory
         labelsToAdd: labelsToAdd
 
   taskForArchiving: ({threads, fromView}) ->
-    category = @_archiveCategory()
+    category = CategoryStore.getArchiveCategory()
     @taskForApplyingCategory({threads, fromView, category, exclusive: true})
 
   taskForUnarchiving: ({threads, fromView}) ->
-    category = @_archiveCategory()
+    category = CategoryStore.getArchiveCategory()
     @taskForRemovingCategory({threads, fromView, category, exclusive: true})
 
   taskForMovingToTrash: ({threads, fromView}) ->
-    category = CategoryStore.getStandardCategory("trash")
+    category = CategoryStore.getTrashCategory()
     @taskForApplyingCategory({threads, fromView, category, exclusive: true})
 
   taskForMovingFromTrash: ({threads, fromView}) ->
-    category = CategoryStore.getStandardCategory("trash")
+    category = CategoryStore.getTrashCategory()
     @taskForRemovingCategory({threads, fromView, category, exclusive: true})
 
   taskForInvertingUnread: ({threads}) ->
@@ -69,11 +69,4 @@ class TaskFactory
     starred = _.every threads, (t) -> _.isMatch(t, {starred: false})
     return new ChangeStarredTask({threads, starred})
 
-  _archiveCategory: (account) ->
-    account = AccountStore.current()
-    if account.usesFolders()
-      return CategoryStore.getStandardCategory("archive")
-    else
-      return CategoryStore.getStandardCategory("all")
-
 module.exports = new TaskFactory

src/mail-view-filter.coffee

@@ -48,16 +48,19 @@ class MailViewFilter
   canApplyToThreads: ->
     throw new Error("canApplyToThreads: Not implemented in base class.")
 
-  # Whether or not the current MailViewFilter can "archive" or "trash"
-  canArchiveThreads: ->
-    throw new Error("canArchiveThreads: Not implemented in base class.")
-
-  canTrashThreads: ->
-    throw new Error("canTrashThreads: Not implemented in base class.")
-
   applyToThreads: (threadsOrIds) ->
     throw new Error("applyToThreads: Not implemented in base class.")
 
+  # Whether or not the current MailViewFilter can "archive" or "trash"
+  # Subclasses should call `super` if they override these methods
+  canArchiveThreads: ->
+    return false unless CategoryStore.getArchiveCategory()
+    return true
+
+  canTrashThreads: ->
+    return false unless CategoryStore.getTrashCategory()
+    return true
+
 class SearchMailViewFilter extends MailViewFilter
   constructor: (@searchQuery) ->
     @
@@ -96,12 +99,6 @@ class StarredMailViewFilter extends MailViewFilter
   canApplyToThreads: ->
     true
 
-  canArchiveThreads: ->
-    true
-
-  canTrashThreads: ->
-    true
-
   applyToThreads: (threadsOrIds) ->
     ChangeStarredTask = require './flux/tasks/change-starred-task'
     task = new ChangeStarredTask({threads:threadsOrIds, starred: true})
@@ -139,13 +136,11 @@ class CategoryMailViewFilter extends MailViewFilter
 
   canArchiveThreads: ->
     return false if @category.name in ["archive", "all", "sent"]
-    return false if @category.displayName is atom.config.get("core.archiveFolder")
-    return false unless CategoryStore.getStandardCategory("archive")
-    return true
+    super
 
   canTrashThreads: ->
     return false if @category.name in ["trash"]
-    return true
+    super
 
   applyToThreads: (threadsOrIds) ->
     if AccountStore.current().usesLabels()