Merge pull request #1787 from michaellennox/add-middleware-insert-dsl

Add documented but not implemented feature so a user can insert a middleware at a specific point in the stack

Author: dblock

CHANGELOG.md

@@ -8,6 +8,7 @@
 
 * Your contribution here.
 * [#1776](https://github.com/ruby-grape/grape/pull/1776): Validate response returned by the exception handler - [@darren987469](https://github.com/darren987469).
+* [#1787](https://github.com/ruby-grape/grape/pull/1787): Add documented but not implemented ability to `.insert` a middleware in the stack - [@michaellennox](https://github.com/michaellennox).
 
 ### 1.1.0 (8/4/2018)
 

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/api_spec.rb

@@ -1348,6 +1348,28 @@ def call(env)
     end
   end
 
+  describe '.insert' do
+    it 'inserts middleware in a specific location in the stack' do
+      m = Class.new(Grape::Middleware::Base) do
+        def call(env)
+          env['phony.args'] ||= []
+          env['phony.args'] << @options[:message]
+          @app.call(env)
+        end
+      end
+
+      subject.use ApiSpec::PhonyMiddleware, 'bye'
+      subject.insert 0, m, message: 'good'
+      subject.insert 0, m, message: 'hello'
+      subject.get '/' do
+        env['phony.args'].join(' ')
+      end
+
+      get '/'
+      expect(last_response.body).to eql 'hello good bye'
+    end
+  end
+
   describe '.http_basic' do
     it 'protects any resources on the same scope' do
       subject.http_basic do |u, _p|

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])