Allow a user to insert a middleware at a specific location in the stack.

This commit adds a documented but not implemented feature to allow a user to insert a middleware at a specific point in the stack. It does this by extending the Grape::DSL::Middleware class with a new method `.insert` which delegates down to the already existing methods in existance on the Grape::Middleware::Stack class.

Author: michaellennox

lib/grape/dsl/middleware.rb

@@ -21,6 +21,13 @@ def use(middleware_class, *args, &block)
           namespace_stackable(:middleware, arr)
         end
 
+        def insert(*args, &block)
+          arr = [:insert, *args]
+          arr << block if block_given?
+
+          namespace_stackable(:middleware, arr)
+        end
+
         def insert_before(*args, &block)
           arr = [:insert_before, *args]
           arr << block if block_given?

spec/grape/dsl/middleware_spec.rb

@@ -22,6 +22,14 @@ class Dummy
         end
       end
 
+      describe '.insert' do
+        it 'adds a middleware with the right operation' do
+          expect(subject).to receive(:namespace_stackable).with(:middleware, [:insert, 0, :arg1, proc])
+
+          subject.insert 0, :arg1, &proc
+        end
+      end
+
       describe '.insert_before' do
         it 'adds a middleware with the right operation' do
           expect(subject).to receive(:namespace_stackable).with(:middleware, [:insert_before, foo_middleware, :arg1, proc])