feat(extension): async extensions

Summary:
WIP:

This is a quick patch for Drew to make extensions async

We'll need to think through the upgrade/deprecation plan to roll out async
extensions across all of our APIs.

Test Plan: TODO

Reviewers: drew, evan, bengotow

Reviewed By: bengotow

Differential Revision: https://phab.nylas.com/D2392

docs/ComposerExtensions.md

@@ -41,5 +41,6 @@ class ProductsExtension extends ComposerExtension
          bodyWithWarning = draft.body += "<br>This email \
          	contains competitor's product names \
         	or trademarks used in context."
-         session.changes.add(body: bodyWithWarning)
+         return session.changes.add(body: bodyWithWarning)
+      else return Promise.resolve()
 ```

examples/N1-Quick-Schedule/lib/availability-composer-extension.coffee

@@ -1,12 +1,13 @@
 {ComposerExtension} = require 'nylas-exports'
 request = require 'request'
+post = Promise.promisify(request.post, multiArgs: true)
 
 class AvailabilityComposerExtension extends ComposerExtension
 
   # When subclassing the ComposerExtension, you can add your own custom logic
   # to execute before a draft is sent in the @finalizeSessionBeforeSending
   # method. Here, we're registering the events before we send the draft.
-  @finalizeSessionBeforeSending: ({session}) ->
+  @finalizeSessionBeforeSending: (session) ->
     body = session.draft().body
     participants = session.draft().participants()
     sender = session.draft().from
@@ -18,8 +19,19 @@ class AvailabilityComposerExtension extends ComposerExtension
       data.attendees = participants.map (p) ->
         name: p.name, email: p.email, isSender: p.isMe()
       serverUrl = "https://quickschedule.herokuapp.com/register-events"
-      request.post {url: serverUrl, body: JSON.stringify(data)}, (error, resp, data) =>
-        console.log(error,resp,data)
+      post({url: serverUrl, body: JSON.stringify(data)})
+      .then (args) =>
+        data = args[1]
+        return data
+      .catch (error) ->
+        dialog = require('remote').require('dialog')
+        dialog.showErrorBox('Error creating QuickSchedule event',
+        "There was a problem connecting to the QuickSchedule server. Make sure you're connected to the internet and "+
+        "try sending again. If problems persist, contact the N1 team (using the blue question icon at the bottom right "+
+        "of your inbox) and we'll get right on it!")
+        Promise.reject(error)
+    else
+      Promise.resolve()
 
 
 module.exports = AvailabilityComposerExtension

internal_packages/composer-spellcheck/lib/spellcheck-composer-extension.coffee

@@ -123,7 +123,7 @@ class SpellcheckComposerExtension extends ComposerExtension
     body = session.draft().body
     clean = body.replace(/<\/?spelling[^>]*>/g, '')
     if body != clean
-      session.changes.add(body: clean)
+      return session.changes.add(body: clean)
 
 SpellcheckComposerExtension.SpellcheckCache = SpellcheckCache
 

internal_packages/composer-spellcheck/spec/spellcheck-composer-extension-spec.coffee

@@ -25,9 +25,10 @@ describe "SpellcheckComposerExtension", ->
         draft: ->
           body: expectedHTML
         changes:
-          add: jasmine.createSpy('add')
+          add: jasmine.createSpy('add').andReturn Promise.resolve()
 
-      SpellcheckComposerExtension.finalizeSessionBeforeSending({session})
-      expect(session.changes.add).toHaveBeenCalledWith(body: initialHTML)
+      waitsForPromise ->
+        SpellcheckComposerExtension.finalizeSessionBeforeSending(session).then ->
+          expect(session.changes.add).toHaveBeenCalledWith(body: initialHTML)
 
 module.exports = SpellcheckComposerExtension

internal_packages/composer/spec/composer-view-spec.cjsx

@@ -124,7 +124,7 @@ describe "ComposerView", ->
     # `componentWillMount`, we manually call sessionForClientId to make this
     # part of the test synchronous. We need to make the `then` block of the
     # sessionForClientId do nothing so `_setupSession` is not called twice!
-    spyOn(DraftStore, "sessionForClientId").andCallFake -> then: ->
+    spyOn(DraftStore, "sessionForClientId").andReturn then: -> then: ->
 
   useFullDraft = ->
     useDraft.call @,

src/extensions/composer-extension.coffee

@@ -28,8 +28,8 @@ session you receive in {::finalizeSessionBeforeSending} is for the same
 draft you previously received in {::warningsForSending}, etc.
 
 The ComposerExtension API does not currently expose any asynchronous or
-{Promise}-based APIs.  This will likely change in the future. If you have
-a use-case for a ComposerExtension that is not possible with the current
+{Promise}-based APIs, except for finalizeSessionBeforeSending. This will likely
+change in the future. If you havea use-case for a ComposerExtension that is not possible with the current
 API, please let us know.
 
 Section: Extensions
@@ -96,6 +96,8 @@ class ComposerExtension extends ContenteditableExtension
   the draft is sent. This method gives you an opportunity to make any
   final substitutions or changes after any {::warningsForSending} have
   been displayed.
+  If you want to perform asynchronous work, you this method can return a promise,
+  however, returning a Promise is not required.
 
   - `session`: A {DraftStoreProxy} for the draft.
 
@@ -110,7 +112,7 @@ class ComposerExtension extends ContenteditableExtension
       session.changes.add(body: clean)
   ```
   ###
-  @finalizeSessionBeforeSending: ({session}) ->
-    return
+  @finalizeSessionBeforeSending: (session) ->
+    return Promise.resolve(session)
 
 module.exports = ComposerExtension

src/flux/stores/draft-store.coffee

@@ -496,10 +496,9 @@ class DraftStore
     # point there are still unpersisted changes in the DraftStoreProxy. If
     # we `trigger`, we'll briefly display the wrong version of the draft
     # as if it was sending.
-
-    @sessionForClientId(draftClientId).then (session) =>
-      @_runExtensionsBeforeSend(session)
-
+    @sessionForClientId(draftClientId)
+    .then(@_runExtensionsBeforeSend)
+    .then (session) =>
       # Immediately save any pending changes so we don't save after
       # sending
       #
@@ -511,7 +510,6 @@ class DraftStore
       # committed to the Database since we'll look them up again just
       # before send.
       session.changes.commit(force: true, noSyncback: true).then =>
-
         # We unfortunately can't give the SendDraftTask the raw draft JSON
         # data because there may still be pending tasks (like a
         # {FileUploadTask}) that will continue to update the draft data.
@@ -532,10 +530,10 @@ class DraftStore
     NylasEnv.getWindowType() is "composer"
 
   # Give third-party plugins an opportunity to sanitize draft data
-  _runExtensionsBeforeSend: (session) ->
-    for extension in @extensions()
-      continue unless extension.finalizeSessionBeforeSending
-      extension.finalizeSessionBeforeSending({session})
+  _runExtensionsBeforeSend: (session) =>
+    Promise.each @extensions(), (ext) ->
+      ext.finalizeSessionBeforeSending(session)
+    .return(session)
 
   _onRemoveFile: ({file, messageClientId}) =>
     @sessionForClientId(messageClientId).then (session) ->