Merge 1e4cd63 into 0636616

lib/pragma/migration.rb

@@ -1,12 +1,15 @@
 # frozen_string_literal: true
 
+require 'rack'
+require 'mustermann'
+
 require 'pragma/migration/base'
 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

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

lib/pragma/migration/repository.rb

@@ -4,25 +4,62 @@ 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
 
-        def migrations_since(user_version)
+        def user_version_proc
+          @user_version_proc ||= begin
+                                   lambda do |request|
+                                     request.get_header('X-Api-Version')
+                                   end
+                                 end
+        end
+
+        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 migration_active?(user_version, 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

lib/pragma/migration/runner.rb

@@ -3,23 +3,22 @@
 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)
-        repository.migrations_since(user_version).each do |migration|
+        repository.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)
+        repository.migrations_for(request).reverse.each do |migration|
           response = migration.new.down(response)
         end
 

lib/pragma/migration/version_number.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+module Pragma
+  module Migration
+    VERSION = '0.1.0'
+  end
+end

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'
@@ -22,10 +21,12 @@ 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

spec/pragma/migration/base_spec.rb

@@ -2,22 +2,35 @@
 
 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

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
@@ -42,21 +48,53 @@
   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]
+      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
-      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_for' 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.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
+      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