fix(signature): Update signature when account is changed in composer

Summary:
- Fixes #1239
- Adds action in composer view to indicate when draft partcipants have
  changed. This seemed like the simplest way to listen for this change without
  adding another extension point
- Updates signature plugin to listen to this action and update signature
  accordingly
- Adds test

Test Plan: - Unit tests

Reviewers: evan, bengotow

Reviewed By: bengotow

Differential Revision: https://phab.nylas.com/D2614

internal_packages/composer-signature/lib/main.coffee

@@ -1,8 +1,9 @@
 {PreferencesUIStore, ExtensionRegistry} = require 'nylas-exports'
 SignatureComposerExtension = require './signature-composer-extension'
+SignatureStore = require './signature-store'
 
 module.exports =
-  activate: (@state={}) ->
+  activate: ->
     @preferencesTab = new PreferencesUIStore.TabItem
       tabId: "Signatures"
       displayName: "Signatures"
@@ -11,8 +12,12 @@ module.exports =
     ExtensionRegistry.Composer.register(SignatureComposerExtension)
     PreferencesUIStore.registerPreferencesTab(@preferencesTab)
 
+    @signatureStore = new SignatureStore()
+    @signatureStore.activate()
+
   deactivate: ->
     ExtensionRegistry.Composer.unregister(SignatureComposerExtension)
     PreferencesUIStore.unregisterPreferencesTab(@preferencesTab.sectionId)
+    @signatureStore.deactivate()
 
-  serialize: -> @state
+  serialize: ->

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

@@ -1,4 +1,5 @@
 {ComposerExtension, AccountStore} = require 'nylas-exports'
+SignatureUtils = require './signature-utils'
 
 class SignatureComposerExtension extends ComposerExtension
   @prepareNewDraft: ({draft}) ->
@@ -6,13 +7,6 @@ class SignatureComposerExtension extends ComposerExtension
     signature = NylasEnv.config.get("nylas.account-#{accountId}.signature")
     return unless signature
 
-    insertionPoint = draft.body.indexOf('<blockquote')
-    signatureHTML = '<div class="nylas-n1-signature">' + signature + '</div>'
-
-    if insertionPoint is -1
-      insertionPoint = draft.body.length
-      signatureHTML = '<br/><br/>' + signatureHTML
-
-    draft.body = draft.body.slice(0, insertionPoint) + signatureHTML + draft.body.slice(insertionPoint)
+    draft.body = SignatureUtils.applySignature(draft.body, signature)
 
 module.exports = SignatureComposerExtension

internal_packages/composer-signature/lib/signature-store.es6

@@ -0,0 +1,33 @@
+import {DraftStore, AccountStore, Actions} from 'nylas-exports';
+import SignatureUtils from './signature-utils';
+
+
+class SignatureStore {
+
+  constructor() {
+    this.unsubscribe = ()=> {};
+  }
+
+  activate() {
+    this.unsubscribe = Actions.draftParticipantsChanged.listen(this.onParticipantsChanged);
+  }
+
+  onParticipantsChanged(draftClientId, changes) {
+    if (!changes.from) { return; }
+    DraftStore.sessionForClientId(draftClientId).then((session)=> {
+      const draft = session.draft()
+      const {accountId} = AccountStore.accountForEmail(changes.from[0].email);
+      const signature = NylasEnv.config.get(`nylas.account-${accountId}.signature`) || "";
+
+      const body = SignatureUtils.applySignature(draft.body, signature);
+      session.changes.add({body})
+    });
+  }
+
+  deactivate() {
+    this.unsubscribe()
+  }
+
+}
+
+export default SignatureStore;

internal_packages/composer-signature/lib/signature-utils.es6

@@ -0,0 +1,29 @@
+
+const SignatureUtils = {
+
+  applySignature(body, signature) {
+    const signatureRegex = /<div class="nylas-n1-signature">.*<\/div>/;
+
+    let signatureHTML = '<div class="nylas-n1-signature">' + signature + '</div>';
+    let insertionPoint = body.search(signatureRegex)
+    let newBody = body;
+
+    // If there is a signature already present
+    if (insertionPoint !== -1) {
+      // Remove it
+      newBody = newBody.replace(signatureRegex, "")
+    } else {
+      insertionPoint = newBody.indexOf('<blockquote');
+
+      if (insertionPoint === -1) {
+        insertionPoint = newBody.length
+        signatureHTML = '<br/><br/>' + signatureHTML
+      }
+    }
+    return newBody.slice(0, insertionPoint) + signatureHTML + newBody.slice(insertionPoint)
+  },
+
+}
+
+export default SignatureUtils;
+

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

@@ -23,6 +23,24 @@ describe "SignatureComposerExtension", ->
         SignatureComposerExtension.prepareNewDraft(draft: b)
         expect(b.body).toEqual('This is a another test.<br/><br/><div class="nylas-n1-signature"><div id="signature">This is my signature.</div></div>')
 
+      it "should replace the signature if a signature is already present", ->
+        a = new Message
+          draft: true
+          body: 'This is a test! <div class="nylas-n1-signature"><div>SIG</div></div><blockquote>Hello world</blockquote>'
+        b = new Message
+          draft: true
+          body: 'This is a test! <div class="nylas-n1-signature"><div>SIG</div></div>'
+        c = new Message
+          draft: true
+          body: 'This is a test! <div class="nylas-n1-signature"></div>'
+
+        SignatureComposerExtension.prepareNewDraft(draft: a)
+        expect(a.body).toEqual("This is a test! <div class=\"nylas-n1-signature\">#{@signature}</div><blockquote>Hello world</blockquote>")
+        SignatureComposerExtension.prepareNewDraft(draft: b)
+        expect(b.body).toEqual("This is a test! <div class=\"nylas-n1-signature\">#{@signature}</div>")
+        SignatureComposerExtension.prepareNewDraft(draft: c)
+        expect(c.body).toEqual("This is a test! <div class=\"nylas-n1-signature\">#{@signature}</div>")
+
     describe "when a signature is not defined", ->
       beforeEach ->
         spyOn(NylasEnv.config, 'get').andCallFake ->

internal_packages/composer/lib/composer-view.cjsx

@@ -619,6 +619,7 @@ class ComposerView extends React.Component
 
   _onChangeParticipants: (changes={}) =>
     @_addToProxy(changes)
+    Actions.draftParticipantsChanged(@props.draftClientId, changes)
 
   _onChangeSubject: (event) =>
     @_addToProxy(subject: event.target.value)

src/flux/actions.coffee

@@ -524,6 +524,8 @@ class Actions
   ###
   @setMetadata: ActionScopeWindow
 
+  @draftParticipantsChanged: ActionScopeWindow
+
 # Read the actions we declared on the dummy Actions object above
 # and translate them into Reflux Actions