From 3b802e2487d74e82df5f2da30e316ca75621d12a Mon Sep 17 00:00:00 2001
From: Alessandro Desantis <desa.alessandro@gmail.com>
Date: Fri, 29 Dec 2017 14:18:05 +0100
Subject: [PATCH 1/6] Implement Rack integration

---
 lib/pragma/migration.rb                  |  3 +
 lib/pragma/migration/base.rb             |  4 ++
 lib/pragma/migration/repository.rb       |  6 ++
 lib/pragma/migration/runner.rb           | 12 +++-
 pragma-migration.gemspec                 |  6 +-
 spec/pragma/migration/base_spec.rb       | 23 +++++--
 spec/pragma/migration/repository_spec.rb | 36 +++++++++-
 spec/pragma/migration/runner_spec.rb     | 87 +++++++++++++++++++-----
 8 files changed, 145 insertions(+), 32 deletions(-)

diff --git a/lib/pragma/migration.rb b/lib/pragma/migration.rb
index 7952c9c..9a3716b 100644
--- a/lib/pragma/migration.rb
+++ b/lib/pragma/migration.rb
@@ -1,5 +1,8 @@
 # frozen_string_literal: true
 
+require 'rack'
+require 'mustermann'
+
 require 'pragma/migration/base'
 require 'pragma/migration/repository'
 require 'pragma/migration/version'
diff --git a/lib/pragma/migration/base.rb b/lib/pragma/migration/base.rb
index ed758a0..9f28162 100644
--- a/lib/pragma/migration/base.rb
+++ b/lib/pragma/migration/base.rb
@@ -13,6 +13,10 @@ def apply_to(pattern)
         def describe(description)
           @description = description
         end
+
+        def applies_to?(request)
+          request.path =~ Mustermann.new(pattern)
+        end
       end
 
       def up(request)
diff --git a/lib/pragma/migration/repository.rb b/lib/pragma/migration/repository.rb
index 6ad86c7..57a8a5d 100644
--- a/lib/pragma/migration/repository.rb
+++ b/lib/pragma/migration/repository.rb
@@ -23,6 +23,12 @@ def migration_active?(user_version, migration)
           end
         end
 
+        def migrations_applying_to(request, user_version:)
+          migrations_since(user_version).select do |migration|
+            migration.applies_to?(request)
+          end
+        end
+
         private
 
         def versions
diff --git a/lib/pragma/migration/runner.rb b/lib/pragma/migration/runner.rb
index 19a5f3a..bd2ea2d 100644
--- a/lib/pragma/migration/runner.rb
+++ b/lib/pragma/migration/runner.rb
@@ -11,20 +11,26 @@ def initialize(repository:, user_version:)
       end
 
       def run_upwards(request)
-        repository.migrations_since(user_version).each do |migration|
+        migrations_for(request).each do |migration|
           request = migration.new.up(request)
         end
 
         request
       end
 
-      def run_downwards(response)
-        repository.migrations_since(user_version).reverse.each do |migration|
+      def run_downwards(request, response)
+        migrations_for(request).reverse.each do |migration|
           response = migration.new.down(response)
         end
 
         response
       end
+
+      private
+
+      def migrations_for(request)
+        repository.migrations_applying_to(request, user_version: user_version)
+      end
     end
   end
 end
diff --git a/pragma-migration.gemspec b/pragma-migration.gemspec
index 8e2802a..1f1d3e8 100644
--- a/pragma-migration.gemspec
+++ b/pragma-migration.gemspec
@@ -22,10 +22,12 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ['lib']
 
-  spec.add_development_dependency 'bundler'
+  spec.add_dependency 'mustermann', '~> 1.0'
+  spec.add_dependency 'rack', '~> 2.0'
+
+  spec.add_development_dependency 'coveralls'
   spec.add_development_dependency 'rake'
   spec.add_development_dependency 'rspec'
   spec.add_development_dependency 'rubocop'
   spec.add_development_dependency 'rubocop-rspec'
-  spec.add_development_dependency 'coveralls'
 end
diff --git a/spec/pragma/migration/base_spec.rb b/spec/pragma/migration/base_spec.rb
index 07dd0b5..f81e20e 100644
--- a/spec/pragma/migration/base_spec.rb
+++ b/spec/pragma/migration/base_spec.rb
@@ -2,22 +2,31 @@
 
 RSpec.describe Pragma::Migration::Base do
   subject(:migration_klass) do
-    Class.new(described_class)
+    Class.new(described_class) do
+      apply_to '/api/v1/articles/*'
+      describe 'Test migration'
+    end
   end
 
   describe '.apply_to' do
-    before { subject.apply_to('test_pattern') }
-
     it 'sets the pattern' do
-      expect(migration_klass.pattern).to eq('test_pattern')
+      expect(migration_klass.pattern).to eq('/api/v1/articles/*')
     end
   end
 
   describe '.describe' do
-    before { subject.describe('test_description') }
-
     it 'sets the description' do
-      expect(migration_klass.description).to eq('test_description')
+      expect(migration_klass.description).to eq('Test migration')
+    end
+  end
+
+  describe '.applies_to?' do
+    it 'returns true when the pattern applies to a path' do
+      expect(migration_klass).to be_applies_to(Rack::Request.new('PATH_INFO' => '/api/v1/articles/1'))
+    end
+
+    it 'returns false when the pattern does not apply to a path' do
+      expect(migration_klass).not_to be_applies_to(Rack::Request.new('PATH_INFO' => '/api/v1/posts/1'))
     end
   end
 end
diff --git a/spec/pragma/migration/repository_spec.rb b/spec/pragma/migration/repository_spec.rb
index 39729b2..e53f3ba 100644
--- a/spec/pragma/migration/repository_spec.rb
+++ b/spec/pragma/migration/repository_spec.rb
@@ -42,13 +42,11 @@
   describe '.migration_active?' do
     let(:migration1) { Class.new(Pragma::Migration::Base) }
     let(:migration2) { Class.new(Pragma::Migration::Base) }
-    let(:migration3) { Class.new(Pragma::Migration::Base) }
 
     before do
       repository.version '2017-12-24'
       repository.version '2017-12-25', [migration1]
       repository.version '2017-12-26', [migration2]
-      repository.version '2017-12-27', [migration3]
     end
 
     it 'returns false when the migration is not active' do
@@ -59,4 +57,38 @@
       expect(repository.migration_active?('2017-12-25', migration2)).to eq(true)
     end
   end
+
+  describe '.migrations_applying_to' do
+    let(:migration1) do
+      Class.new(Pragma::Migration::Base) do
+        apply_to '/api/v1/articles/*'
+      end
+    end
+
+    let(:migration2) do
+      Class.new(Pragma::Migration::Base) do
+        apply_to '/api/v1/articles/*'
+      end
+    end
+
+    let(:migration3) do
+      Class.new(Pragma::Migration::Base) do
+        apply_to '/api/v1/posts/*'
+      end
+    end
+
+    before do
+      repository.version '2017-12-24'
+      repository.version '2017-12-25', [migration1]
+      repository.version '2017-12-26', [migration2]
+      repository.version '2017-12-27', [migration3]
+    end
+
+    it 'returns the migrations applying to the current request' do
+      expect(repository.migrations_applying_to(
+        Rack::Request.new('PATH_INFO' => '/api/v1/articles/1'),
+        user_version: '2017-12-25'
+      )).to eq([migration2])
+    end
+  end
 end
diff --git a/spec/pragma/migration/runner_spec.rb b/spec/pragma/migration/runner_spec.rb
index 4714f7d..3fe7134 100644
--- a/spec/pragma/migration/runner_spec.rb
+++ b/spec/pragma/migration/runner_spec.rb
@@ -6,32 +6,62 @@
   let(:repository) do
     Class.new(Pragma::Migration::Repository) do
       remove_author_name = Class.new(Pragma::Migration::Base) do
+        apply_to '/api/v1/articles/:id'
+
         def up(request)
-          request.delete(:author_name)
+          request.tap { |r| r.params.delete('author_name') }
         end
 
         def down(response)
-          response.merge(author_name: 'John')
+          parsed_body = JSON.parse(response.body)
+
+          Rack::Response.new(
+            JSON.dump(parsed_body.merge('author_name' => 'John')),
+            response.status,
+            response.headers
+          )
         end
       end
 
       rename_author_to_author_id = Class.new(Pragma::Migration::Base) do
+        apply_to '/api/v1/articles/:id'
+
         def up(request)
-          request.merge(author: request.delete(:author_id))
+          request.tap { |r| r.params['author'] = r.params.delete('author_id') }
         end
 
         def down(response)
-          response.merge(author_id: response.delete(:author))
+          parsed_body = JSON.parse(response.body.first)
+
+          Rack::Response.new(
+            JSON.dump(parsed_body.merge(
+              'author_id' => parsed_body.delete('author')
+            )),
+            response.status,
+            response.headers
+          )
         end
       end
 
       convert_published_at_into_unix_epoch = Class.new(Pragma::Migration::Base) do
+        apply_to '/api/v1/articles/:id'
+
         def up(request)
-          request.merge(published_at: Time.new(request[:published_at]).to_i)
+          request.tap do |r|
+            r.params['published_at'] = Time.new(request.params['published_at']).to_i
+          end
         end
 
         def down(response)
-          response.merge(published_at: Time.at(response[:published_at]).to_s)
+          parsed_body = JSON.parse(response.body.first)
+
+          Rack::Response.new(
+            JSON.dump(parsed_body.merge(
+              'published_at' => Time.at(parsed_body['published_at']).to_s
+            )),
+            response.status,
+            response.headers
+          )
         end
       end
 
@@ -58,16 +88,23 @@ def down(response)
     let(:time) { Time.new('2014-11-06T10:40:54+11:00') }
 
     let(:request) do
-      {
-        author_id: 'test_id',
-        published_at: time.to_s
-      }
+      Rack::Request.new(
+        'PATH_INFO' => '/api/v1/articles/1',
+        'rack.input' => ''
+      ).tap do |r|
+        {
+          'author_id' => 'test_id',
+          'published_at' => time.to_s
+        }.each_pair do |key, value|
+          r.update_param key, value
+        end
+      end
     end
 
     it 'applies the migrations to the request' do
-      expect(subject.run_upwards(request)).to eq(
-        author: 'test_id',
-        published_at: time.to_i
+      expect(subject.run_upwards(request).params).to eq(
+        'author' => 'test_id',
+        'published_at' => time.to_i
       )
     end
   end
@@ -75,17 +112,31 @@ def down(response)
   describe '#run_downwards' do
     let(:time) { Time.new('2014-11-06T10:40:54+11:00') }
 
+    let(:request) do
+      Rack::Request.new(
+        'PATH_INFO' => '/api/v1/articles/1',
+        'rack.input' => ''
+      ).tap do |r|
+        {
+          'author_id' => 'test_id',
+          'published_at' => time.to_s
+        }.each_pair do |key, value|
+          r.update_param key, value
+        end
+      end
+    end
+
     let(:response) do
-      {
+      Rack::Response.new(JSON.dump(
         author: 'test_id',
         published_at: time.to_i
-      }
+      ))
     end
 
     it 'applies the migrations to the response' do
-      expect(subject.run_downwards(response)).to eq(
-        published_at: time.to_s,
-        author_id: 'test_id'
+      expect(JSON.parse(subject.run_downwards(request, response).body.first)).to eq(
+        'published_at' => time.to_s,
+        'author_id' => 'test_id'
       )
     end
   end

From bcd30738e55310a54d9a0ffb3269381661e1ae85 Mon Sep 17 00:00:00 2001
From: Alessandro Desantis <desa.alessandro@gmail.com>
Date: Fri, 29 Dec 2017 18:36:23 +0100
Subject: [PATCH 2/6] Put version number in its own file

---
 lib/pragma/migration.rb                | 2 +-
 lib/pragma/migration/version_number.rb | 5 +++++
 pragma-migration.gemspec               | 3 +--
 3 files changed, 7 insertions(+), 3 deletions(-)
 create mode 100644 lib/pragma/migration/version_number.rb

diff --git a/lib/pragma/migration.rb b/lib/pragma/migration.rb
index 9a3716b..74d74c3 100644
--- a/lib/pragma/migration.rb
+++ b/lib/pragma/migration.rb
@@ -7,9 +7,9 @@
 require 'pragma/migration/repository'
 require 'pragma/migration/version'
 require 'pragma/migration/runner'
+require 'pragma/migration/version_number'
 
 module Pragma
   module Migration
-    VERSION = '0.1.0'
   end
 end
diff --git a/lib/pragma/migration/version_number.rb b/lib/pragma/migration/version_number.rb
new file mode 100644
index 0000000..4ffe9ef
--- /dev/null
+++ b/lib/pragma/migration/version_number.rb
@@ -0,0 +1,5 @@
+module Pragma
+  module Migration
+    VERSION = '0.1.0'
+  end
+end
diff --git a/pragma-migration.gemspec b/pragma-migration.gemspec
index 1f1d3e8..76799ee 100644
--- a/pragma-migration.gemspec
+++ b/pragma-migration.gemspec
@@ -1,9 +1,8 @@
-
 # frozen_string_literal: true
 
 lib = File.expand_path('../lib', __FILE__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
-require 'pragma/migration'
+require 'pragma/migration/version_number'
 
 Gem::Specification.new do |spec|
   spec.name          = 'pragma-migration'

From bfe6f238855bd7ff72496bdf0d148c85f1a2ab89 Mon Sep 17 00:00:00 2001
From: Alessandro Desantis <desa.alessandro@gmail.com>
Date: Fri, 29 Dec 2017 18:37:24 +0100
Subject: [PATCH 3/6] Fix coding style issues

---
 lib/pragma/migration/version_number.rb | 2 ++
 spec/pragma/migration/base_spec.rb     | 8 ++++++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/lib/pragma/migration/version_number.rb b/lib/pragma/migration/version_number.rb
index 4ffe9ef..04f5b11 100644
--- a/lib/pragma/migration/version_number.rb
+++ b/lib/pragma/migration/version_number.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Pragma
   module Migration
     VERSION = '0.1.0'
diff --git a/spec/pragma/migration/base_spec.rb b/spec/pragma/migration/base_spec.rb
index f81e20e..0fd0fe5 100644
--- a/spec/pragma/migration/base_spec.rb
+++ b/spec/pragma/migration/base_spec.rb
@@ -22,11 +22,15 @@
 
   describe '.applies_to?' do
     it 'returns true when the pattern applies to a path' do
-      expect(migration_klass).to be_applies_to(Rack::Request.new('PATH_INFO' => '/api/v1/articles/1'))
+      expect(migration_klass).to be_applies_to(
+        Rack::Request.new('PATH_INFO' => '/api/v1/articles/1')
+      )
     end
 
     it 'returns false when the pattern does not apply to a path' do
-      expect(migration_klass).not_to be_applies_to(Rack::Request.new('PATH_INFO' => '/api/v1/posts/1'))
+      expect(migration_klass).not_to be_applies_to(
+        Rack::Request.new('PATH_INFO' => '/api/v1/posts/1')
+      )
     end
   end
 end

From 6ad7761720833496e911f00eb7efacfc70a0eeaf Mon Sep 17 00:00:00 2001
From: Alessandro Desantis <desa.alessandro@gmail.com>
Date: Fri, 29 Dec 2017 18:46:31 +0100
Subject: [PATCH 4/6] Make DSL methods protected

---
 lib/pragma/migration/base.rb             | 10 ++++---
 lib/pragma/migration/repository.rb       | 12 ++++----
 spec/pragma/migration/repository_spec.rb | 36 ++++++++++++++----------
 3 files changed, 34 insertions(+), 24 deletions(-)

diff --git a/lib/pragma/migration/base.rb b/lib/pragma/migration/base.rb
index 9f28162..4c204e7 100644
--- a/lib/pragma/migration/base.rb
+++ b/lib/pragma/migration/base.rb
@@ -6,6 +6,12 @@ class Base
       class << self
         attr_reader :pattern, :description
 
+        def applies_to?(request)
+          request.path =~ Mustermann.new(pattern)
+        end
+
+        protected
+
         def apply_to(pattern)
           @pattern = pattern
         end
@@ -13,10 +19,6 @@ def apply_to(pattern)
         def describe(description)
           @description = description
         end
-
-        def applies_to?(request)
-          request.path =~ Mustermann.new(pattern)
-        end
       end
 
       def up(request)
diff --git a/lib/pragma/migration/repository.rb b/lib/pragma/migration/repository.rb
index 57a8a5d..143540f 100644
--- a/lib/pragma/migration/repository.rb
+++ b/lib/pragma/migration/repository.rb
@@ -4,11 +4,6 @@ module Pragma
   module Migration
     class Repository
       class << self
-        def version(number, migrations = [])
-          versions << Version.new(number, migrations)
-          sort_versions
-        end
-
         def sorted_versions
           versions.dup
         end
@@ -29,6 +24,13 @@ def migrations_applying_to(request, user_version:)
           end
         end
 
+        protected
+
+        def version(number, migrations = [])
+          versions << Version.new(number, migrations)
+          sort_versions
+        end
+
         private
 
         def versions
diff --git a/spec/pragma/migration/repository_spec.rb b/spec/pragma/migration/repository_spec.rb
index e53f3ba..3199a8a 100644
--- a/spec/pragma/migration/repository_spec.rb
+++ b/spec/pragma/migration/repository_spec.rb
@@ -5,19 +5,25 @@
 
   describe '.version' do
     it 'adds a version' do
-      repository.version '2017-12-27'
+      repository.instance_eval do
+        version '2017-12-27'
+      end
+
       expect(repository.sorted_versions).to match([instance_of(Pragma::Migration::Version)])
     end
 
     it 'keeps versions sorted' do
-      repository.version '2017-12-28'
-      repository.version '2017-12-27'
+      repository.instance_eval do
+        version '2017-12-28'
+        version '2017-12-27'
+      end
+
       expect(repository.sorted_versions.map(&:number)).to eq(['2017-12-27', '2017-12-28'])
     end
 
     it 'initializes migrations' do
       migration = Class.new(Pragma::Migration::Base)
-      repository.version '2017-12-28', [migration]
+      repository.send :version, '2017-12-28', [migration]
       expect(repository.sorted_versions.first.migrations).to eq([migration])
     end
   end
@@ -28,10 +34,10 @@
     let(:migration3) { Class.new(Pragma::Migration::Base) }
 
     before do
-      repository.version '2017-12-24'
-      repository.version '2017-12-25', [migration1]
-      repository.version '2017-12-26', [migration2]
-      repository.version '2017-12-27', [migration3]
+      repository.send :version, '2017-12-24'
+      repository.send :version, '2017-12-25', [migration1]
+      repository.send :version, '2017-12-26', [migration2]
+      repository.send :version, '2017-12-27', [migration3]
     end
 
     it 'collects all the changes since the specified version' do
@@ -44,9 +50,9 @@
     let(:migration2) { Class.new(Pragma::Migration::Base) }
 
     before do
-      repository.version '2017-12-24'
-      repository.version '2017-12-25', [migration1]
-      repository.version '2017-12-26', [migration2]
+      repository.send :version, '2017-12-24'
+      repository.send :version, '2017-12-25', [migration1]
+      repository.send :version, '2017-12-26', [migration2]
     end
 
     it 'returns false when the migration is not active' do
@@ -78,10 +84,10 @@
     end
 
     before do
-      repository.version '2017-12-24'
-      repository.version '2017-12-25', [migration1]
-      repository.version '2017-12-26', [migration2]
-      repository.version '2017-12-27', [migration3]
+      repository.send :version, '2017-12-24'
+      repository.send :version, '2017-12-25', [migration1]
+      repository.send :version, '2017-12-26', [migration2]
+      repository.send :version, '2017-12-27', [migration3]
     end
 
     it 'returns the migrations applying to the current request' do

From 4b253483cd83ebfe0612575fb62dd51f11906402 Mon Sep 17 00:00:00 2001
From: Alessandro Desantis <desa.alessandro@gmail.com>
Date: Fri, 29 Dec 2017 19:02:59 +0100
Subject: [PATCH 5/6] Move user version calculation to Repository

---
 lib/pragma/migration/repository.rb       | 41 ++++++++++++++++++++----
 lib/pragma/migration/runner.rb           | 15 +++------
 spec/pragma/migration/repository_spec.rb | 14 ++++----
 spec/pragma/migration/runner_spec.rb     |  8 +++--
 4 files changed, 50 insertions(+), 28 deletions(-)

diff --git a/lib/pragma/migration/repository.rb b/lib/pragma/migration/repository.rb
index 143540f..dec425e 100644
--- a/lib/pragma/migration/repository.rb
+++ b/lib/pragma/migration/repository.rb
@@ -8,29 +8,56 @@ def sorted_versions
           versions.dup
         end
 
-        def migrations_since(user_version)
-          @versions.select { |version| version > user_version }.flat_map(&:migrations)
+        def user_version_proc
+          @user_version_proc ||= (lambda do |request|
+            request.get_header('X-Api-Version')
+          end)
         end
 
-        def migration_active?(user_version, migration)
-          @versions.any? do |version|
-            version > user_version && version.migration?(migration)
+        def migrations_since(request_or_version)
+          user_version = if request_or_version.is_a?(Rack::Request)
+            user_version_from(request_or_version)
+          else
+            request_or_version
           end
+
+          @versions.select { |version| version > user_version }.flat_map(&:migrations)
         end
 
-        def migrations_applying_to(request, user_version:)
-          migrations_since(user_version).select do |migration|
+        def migrations_for(request)
+          migrations_since(request).select do |migration|
             migration.applies_to?(request)
           end
         end
 
+        def migration_active?(migration, request: nil, user_version: nil)
+          unless request || user_version
+            fail ArgumentError, 'You must pass one of :request or :user_version'
+          end
+
+          user_version ||= user_version_from(request)
+
+          @versions.any? do |version|
+            version > user_version && version.migration?(migration)
+          end
+        end
+
         protected
 
+        def user_version_from(request)
+          user_version = user_version_proc.call(request)
+          sorted_versions.include?(user_version) ? user_version : sorted_versions.last
+        end
+
         def version(number, migrations = [])
           versions << Version.new(number, migrations)
           sort_versions
         end
 
+        def user_version(&block)
+          @user_version_proc = block
+        end
+
         private
 
         def versions
diff --git a/lib/pragma/migration/runner.rb b/lib/pragma/migration/runner.rb
index bd2ea2d..d84a4fa 100644
--- a/lib/pragma/migration/runner.rb
+++ b/lib/pragma/migration/runner.rb
@@ -3,15 +3,14 @@
 module Pragma
   module Migration
     class Runner
-      attr_reader :repository, :user_version
+      attr_reader :repository
 
-      def initialize(repository:, user_version:)
+      def initialize(repository)
         @repository = repository
-        @user_version = user_version
       end
 
       def run_upwards(request)
-        migrations_for(request).each do |migration|
+        repository.migrations_for(request).each do |migration|
           request = migration.new.up(request)
         end
 
@@ -19,18 +18,12 @@ def run_upwards(request)
       end
 
       def run_downwards(request, response)
-        migrations_for(request).reverse.each do |migration|
+        repository.migrations_for(request).reverse.each do |migration|
           response = migration.new.down(response)
         end
 
         response
       end
-
-      private
-
-      def migrations_for(request)
-        repository.migrations_applying_to(request, user_version: user_version)
-      end
     end
   end
 end
diff --git a/spec/pragma/migration/repository_spec.rb b/spec/pragma/migration/repository_spec.rb
index 3199a8a..25817b2 100644
--- a/spec/pragma/migration/repository_spec.rb
+++ b/spec/pragma/migration/repository_spec.rb
@@ -56,15 +56,15 @@
     end
 
     it 'returns false when the migration is not active' do
-      expect(repository.migration_active?('2017-12-25', migration1)).to eq(false)
+      expect(repository.migration_active?(migration1, user_version: '2017-12-25')).to eq(false)
     end
 
     it 'returns true when the migration is active' do
-      expect(repository.migration_active?('2017-12-25', migration2)).to eq(true)
+      expect(repository.migration_active?(migration2, user_version: '2017-12-25')).to eq(true)
     end
   end
 
-  describe '.migrations_applying_to' do
+  describe '.migrations_for' do
     let(:migration1) do
       Class.new(Pragma::Migration::Base) do
         apply_to '/api/v1/articles/*'
@@ -91,10 +91,10 @@
     end
 
     it 'returns the migrations applying to the current request' do
-      expect(repository.migrations_applying_to(
-        Rack::Request.new('PATH_INFO' => '/api/v1/articles/1'),
-        user_version: '2017-12-25'
-      )).to eq([migration2])
+      expect(repository.migrations_for(Rack::Request.new(
+        'PATH_INFO' => '/api/v1/articles/1',
+        'X-Api-Version' => '2017-12-25'
+      ))).to eq([migration2])
     end
   end
 end
diff --git a/spec/pragma/migration/runner_spec.rb b/spec/pragma/migration/runner_spec.rb
index 3fe7134..d36fd05 100644
--- a/spec/pragma/migration/runner_spec.rb
+++ b/spec/pragma/migration/runner_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 RSpec.describe Pragma::Migration::Runner do
-  subject { described_class.new(repository: repository, user_version: user_version) }
+  subject { described_class.new(repository) }
 
   let(:repository) do
     Class.new(Pragma::Migration::Repository) do
@@ -90,7 +90,8 @@ def down(response)
     let(:request) do
       Rack::Request.new(
         'PATH_INFO' => '/api/v1/articles/1',
-        'rack.input' => ''
+        'rack.input' => '',
+        'X-Api-Version' => '2017-12-25',
       ).tap do |r|
         {
           'author_id' => 'test_id',
@@ -115,7 +116,8 @@ def down(response)
     let(:request) do
       Rack::Request.new(
         'PATH_INFO' => '/api/v1/articles/1',
-        'rack.input' => ''
+        'rack.input' => '',
+        'X-Api-Version' => '2017-12-25',
       ).tap do |r|
         {
           'author_id' => 'test_id',

From 1e4cd63a2326328c28926208884d67d604750e1f Mon Sep 17 00:00:00 2001
From: Alessandro Desantis <desa.alessandro@gmail.com>
Date: Fri, 29 Dec 2017 19:03:49 +0100
Subject: [PATCH 6/6] Fix coding style issues

---
 lib/pragma/migration/repository.rb   | 8 +++++---
 spec/pragma/migration/runner_spec.rb | 4 ++--
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/lib/pragma/migration/repository.rb b/lib/pragma/migration/repository.rb
index dec425e..0e6e16f 100644
--- a/lib/pragma/migration/repository.rb
+++ b/lib/pragma/migration/repository.rb
@@ -9,9 +9,11 @@ def sorted_versions
         end
 
         def user_version_proc
-          @user_version_proc ||= (lambda do |request|
-            request.get_header('X-Api-Version')
-          end)
+          @user_version_proc ||= begin
+                                   lambda do |request|
+                                     request.get_header('X-Api-Version')
+                                   end
+                                 end
         end
 
         def migrations_since(request_or_version)
diff --git a/spec/pragma/migration/runner_spec.rb b/spec/pragma/migration/runner_spec.rb
index d36fd05..f44583b 100644
--- a/spec/pragma/migration/runner_spec.rb
+++ b/spec/pragma/migration/runner_spec.rb
@@ -91,7 +91,7 @@ def down(response)
       Rack::Request.new(
         'PATH_INFO' => '/api/v1/articles/1',
         'rack.input' => '',
-        'X-Api-Version' => '2017-12-25',
+        'X-Api-Version' => '2017-12-25'
       ).tap do |r|
         {
           'author_id' => 'test_id',
@@ -117,7 +117,7 @@ def down(response)
       Rack::Request.new(
         'PATH_INFO' => '/api/v1/articles/1',
         'rack.input' => '',
-        'X-Api-Version' => '2017-12-25',
+        'X-Api-Version' => '2017-12-25'
       ).tap do |r|
         {
           'author_id' => 'test_id',