1 files changed, 48 insertions, 23 deletions

diff --git a/actionmailer/lib/action_mailer/preview.rb b/actionmailer/lib/action_mailer/preview.rb
index aab92fe8db..500b3bede0 100644
--- a/actionmailer/lib/action_mailer/preview.rb
+++ b/actionmailer/lib/action_mailer/preview.rb
@@ -1,4 +1,6 @@
-require 'active_support/descendants_tracker'
+# frozen_string_literal: true
+
+require "active_support/descendants_tracker"
 
 module ActionMailer
   module Previews #:nodoc:
@@ -15,13 +17,12 @@ module ActionMailer
       #
       #     config.action_mailer.show_previews = true
       #
-      # Defaults to true for development environment
+      # Defaults to +true+ for development environment
       #
       mattr_accessor :show_previews, instance_writer: false
 
       # :nodoc:
-      mattr_accessor :preview_interceptors, instance_writer: false
-      self.preview_interceptors = [ActionMailer::InlinePreviewInterceptor]
+      mattr_accessor :preview_interceptors, instance_writer: false, default: [ActionMailer::InlinePreviewInterceptor]
     end
 
     module ClassMethods
@@ -30,27 +31,51 @@ module ActionMailer
         interceptors.flatten.compact.each { |interceptor| register_preview_interceptor(interceptor) }
       end
 
+      # Unregister one or more previously registered Interceptors.
+      def unregister_preview_interceptors(*interceptors)
+        interceptors.flatten.compact.each { |interceptor| unregister_preview_interceptor(interceptor) }
+      end
+
       # Register an Interceptor which will be called before mail is previewed.
       # Either a class or a string can be passed in as the Interceptor. If a
-      # string is passed in it will be <tt>constantize</tt>d.
+      # string is passed in it will be constantized.
       def register_preview_interceptor(interceptor)
-        preview_interceptor = case interceptor
+        preview_interceptor = interceptor_class_for(interceptor)
+
+        unless preview_interceptors.include?(preview_interceptor)
+          preview_interceptors << preview_interceptor
+        end
+      end
+
+      # Unregister a previously registered Interceptor.
+      # Either a class or a string can be passed in as the Interceptor. If a
+      # string is passed in it will be constantized.
+      def unregister_preview_interceptor(interceptor)
+        preview_interceptors.delete(interceptor_class_for(interceptor))
+      end
+
+      private
+
+        def interceptor_class_for(interceptor)
+          case interceptor
           when String, Symbol
             interceptor.to_s.camelize.constantize
           else
             interceptor
           end
-
-        unless preview_interceptors.include?(preview_interceptor)
-          preview_interceptors << preview_interceptor
         end
-      end
     end
   end
 
   class Preview
     extend ActiveSupport::DescendantsTracker
 
+    attr_reader :params
+
+    def initialize(params = {})
+      @params = params
+    end
+
     class << self
       # Returns all mailer preview classes.
       def all
@@ -61,8 +86,8 @@ module ActionMailer
       # Returns the mail object for the given email name. The registered preview
       # interceptors will be informed so that they can transform the message
       # as they would if the mail was actually being delivered.
-      def call(email)
-        preview = self.new
+      def call(email, params = {})
+        preview = new(params)
         message = preview.public_send(email)
         inform_preview_interceptors(message)
         message
@@ -73,42 +98,42 @@ module ActionMailer
         public_instance_methods(false).map(&:to_s).sort
       end
 
-      # Returns true if the email exists.
+      # Returns +true+ if the email exists.
       def email_exists?(email)
         emails.include?(email)
       end
 
-      # Returns true if the preview exists.
+      # Returns +true+ if the preview exists.
       def exists?(preview)
-        all.any?{ |p| p.preview_name == preview }
+        all.any? { |p| p.preview_name == preview }
       end
 
       # Find a mailer preview by its underscored class name.
       def find(preview)
-        all.find{ |p| p.preview_name == preview }
+        all.find { |p| p.preview_name == preview }
       end
 
       # Returns the underscored name of the mailer preview without the suffix.
       def preview_name
-        name.sub(/Preview$/, '').underscore
+        name.sub(/Preview$/, "").underscore
       end
 
-      protected
-        def load_previews #:nodoc:
+      private
+        def load_previews
           if preview_path
-            Dir["#{preview_path}/**/*_preview.rb"].each{ |file| require_dependency file }
+            Dir["#{preview_path}/**/*_preview.rb"].sort.each { |file| require_dependency file }
           end
         end
 
-        def preview_path #:nodoc:
+        def preview_path
           Base.preview_path
         end
 
-        def show_previews #:nodoc:
+        def show_previews
           Base.show_previews
         end
 
-        def inform_preview_interceptors(message) #:nodoc:
+        def inform_preview_interceptors(message)
           Base.preview_interceptors.each do |interceptor|
             interceptor.previewing_email(message)
           end