Merge pull request sidekiq#2029 from seuros/prepend

Introduce chain#prepend

Changes.md

@@ -2,11 +2,12 @@ HEAD
 -----------
 
 - Fix typo for generator test file name [dlackty, #2016]
+- Add Sidekiq::Middleware::Chain#prepend [seuros, #2029]
 
 3.2.6
 -----------
 
-- Deprecate delay extension for ActionMailer 4.2+ . [#1933]
+- Deprecate delay extension for ActionMailer 4.2+ . [seuros, #1933]
 - Poll interval tuning now accounts for dead processes [epchris, #1984]
 - Add non-production environment to Web UI page titles [JacobEvelyn, #2004]
 

lib/sidekiq/middleware/chain.rb

@@ -89,6 +89,11 @@ def add(klass, *args)
         entries << Entry.new(klass, *args)
       end
 
+      def prepend(klass, *args)
+        remove(klass) if exists?(klass)
+        entries.insert(0, Entry.new(klass, *args))
+      end
+
       def insert_before(oldklass, newklass, *args)
         i = entries.index { |entry| entry.klass == newklass }
         new_entry = i.nil? ? Entry.new(newklass, *args) : entries.delete_at(i)

test/test_middleware.rb

@@ -96,6 +96,15 @@ def call(*args)
       assert_equal 1, chain.count
     end
 
+    it 'correctly prepends middleware' do
+      chain = Sidekiq::Middleware::Chain.new
+      chain_entries = chain.entries
+      chain.add CustomMiddleware
+      chain.prepend YetAnotherCustomMiddleware
+      assert_equal YetAnotherCustomMiddleware, chain_entries.first.klass
+      assert_equal CustomMiddleware, chain_entries.last.klass
+    end
+
     it 'allows middleware to abruptly stop processing rest of chain' do
       recorder = []
       chain = Sidekiq::Middleware::Chain.new