Extract serialize functionality from ::deactivatePackage. Tests WIP

src/package-manager.coffee

@@ -467,6 +467,15 @@ class PackageManager
     return unless hook? and _.isString(hook) and hook.length > 0
     @activationHookEmitter.on(hook, callback)
 
+  serialize: ->
+    for pack in @getLoadedPackages()
+      @serializePackage(pack)
+    @packageStates
+
+  serializePackage: (pack) ->
+    if @isPackageActive(pack.name)
+      @setPackageState(pack.name, state) if state = pack.serialize?()
+
   # Deactivate all packages
   deactivatePackages: ->
     @config.transact =>
@@ -478,8 +487,6 @@ class PackageManager
   # Deactivate the package with the given name
   deactivatePackage: (name) ->
     pack = @getLoadedPackage(name)
-    if @isPackageActive(name)
-      @setPackageState(pack.name, state) if state = pack.serialize?()
     pack.deactivate()
     delete @activePackages[pack.name]
     delete @activatingPackages[pack.name]