Use #cache_key of subject for generated redis key

This commit also includes some changes in specs to use
`Class.new` approach.

lib/gitlab/markdown_cache/redis/store.rb

@@ -48,7 +48,7 @@ module Gitlab
                   "This class has no id to use for caching"
           end
 
-          "markdown_cache:#{@subject.class}:#{@subject.id}"
+          "markdown_cache:#{@subject.cache_key}"
         end
       end
     end

spec/lib/gitlab/markdown_cache/active_record/extension_spec.rb

@@ -2,17 +2,19 @@
 require 'spec_helper'
 
 describe Gitlab::MarkdownCache::ActiveRecord::Extension do
-  class ARThingWithMarkdownFields < ActiveRecord::Base
-    self.table_name = 'issues'
-    include CacheMarkdownField
-    cache_markdown_field :title, whitelisted: true
-    cache_markdown_field :description, pipeline: :single_line
+  let(:klass) do
+    Class.new(ActiveRecord::Base) do
+      self.table_name = 'issues'
+      include CacheMarkdownField
+      cache_markdown_field :title, whitelisted: true
+      cache_markdown_field :description, pipeline: :single_line
 
-    attr_accessor :author, :project
+      attr_accessor :author, :project
+    end
   end
 
   let(:cache_version) { Gitlab::MarkdownCache::CACHE_COMMONMARK_VERSION << 16 }
-  let(:thing) { ARThingWithMarkdownFields.new(title: markdown, title_html: html, cached_markdown_version: cache_version) }
+  let(:thing) { klass.new(title: markdown, title_html: html, cached_markdown_version: cache_version) }
 
   let(:markdown) { '`Foo`' }
   let(:html) { '<p data-sourcepos="1:1-1:5" dir="auto"><code>Foo</code></p>' }
@@ -21,7 +23,7 @@ describe Gitlab::MarkdownCache::ActiveRecord::Extension do
   let(:updated_html) { '<p data-sourcepos="1:1-1:5" dir="auto"><code>Bar</code></p>' }
 
   context 'an unchanged markdown field' do
-    let(:thing) { ARThingWithMarkdownFields.new(title: markdown) }
+    let(:thing) { klass.new(title: markdown) }
 
     before do
       thing.title = thing.title
@@ -35,7 +37,7 @@ describe Gitlab::MarkdownCache::ActiveRecord::Extension do
   end
 
   context 'a changed markdown field' do
-    let(:thing) { ARThingWithMarkdownFields.new(title: markdown, title_html: html, cached_markdown_version: cache_version) }
+    let(:thing) { klass.new(title: markdown, title_html: html, cached_markdown_version: cache_version) }
 
     before do
       thing.title = updated_markdown
@@ -67,7 +69,7 @@ describe Gitlab::MarkdownCache::ActiveRecord::Extension do
   end
 
   context 'a non-markdown field changed' do
-    let(:thing) { ARThingWithMarkdownFields.new(title: markdown, title_html: html, cached_markdown_version: cache_version) }
+    let(:thing) { klass.new(title: markdown, title_html: html, cached_markdown_version: cache_version) }
 
     before do
       thing.state = 'closed'
@@ -81,7 +83,7 @@ describe Gitlab::MarkdownCache::ActiveRecord::Extension do
   end
 
   context 'version is out of date' do
-    let(:thing) { ARThingWithMarkdownFields.new(title: updated_markdown, title_html: html, cached_markdown_version: nil) }
+    let(:thing) { klass.new(title: updated_markdown, title_html: html, cached_markdown_version: nil) }
 
     before do
       thing.save
@@ -122,7 +124,7 @@ describe Gitlab::MarkdownCache::ActiveRecord::Extension do
   end
 
   describe '#cached_html_up_to_date?' do
-    let(:thing) { ARThingWithMarkdownFields.create(title: updated_markdown, title_html: html, cached_markdown_version: nil) }
+    let(:thing) { klass.create(title: updated_markdown, title_html: html, cached_markdown_version: nil) }
     subject { thing.cached_html_up_to_date?(:title) }
 
     it 'returns false if markdown has been changed but html has not' do

spec/lib/gitlab/markdown_cache/redis/extension_spec.rb

@@ -2,30 +2,34 @@
 require 'spec_helper'
 
 describe Gitlab::MarkdownCache::Redis::Extension, :clean_gitlab_redis_cache do
-  class ThingWithMarkdownFields
-    include CacheMarkdownField
+  let(:klass) do
+    Class.new do
+      include CacheMarkdownField
 
-    def initialize(title: nil, description: nil)
-      @title, @description = title, description
-    end
+      def initialize(title: nil, description: nil)
+        @title, @description = title, description
+      end
+
+      attr_reader :title, :description
 
-    attr_reader :title, :description
+      cache_markdown_field :title, pipeline: :single_line
+      cache_markdown_field :description
 
-    cache_markdown_field :title, pipeline: :single_line
-    cache_markdown_field :description
+      def id
+        "test-markdown-cache"
+      end
 
-    def id
-      "test-markdown-cache"
+      def cache_key
+        "cache-key"
+      end
     end
   end
 
   let(:cache_version) { Gitlab::MarkdownCache::CACHE_COMMONMARK_VERSION << 16 }
-  let(:thing) { ThingWithMarkdownFields.new(title: "`Hello`", description: "`World`") }
-  let(:expected_cache_key) { "markdown_cache:ThingWithMarkdownFields:test-markdown-cache" }
+  let(:thing) { klass.new(title: "`Hello`", description: "`World`") }
+  let(:expected_cache_key) { "markdown_cache:cache-key" }
 
   it 'defines the html attributes' do
-    thing = ThingWithMarkdownFields.new
-
     expect(thing).to respond_to(:title_html, :description_html, :cached_markdown_version)
   end
 

spec/lib/gitlab/markdown_cache/redis/store_spec.rb

@@ -16,10 +16,14 @@ describe Gitlab::MarkdownCache::Redis::Store, :clean_gitlab_redis_cache do
       def id
         'test-redisbacked-store'
       end
+
+      def cache_key
+        "cache-key"
+      end
     end
   end
   let(:storable) { storable_class.new }
-  let(:cache_key) { "markdown_cache:#{storable_class}:#{storable.id}" }
+  let(:cache_key) { "markdown_cache:#{storable.cache_key}" }
 
   subject(:store) { described_class.new(storable) }
 

spec/models/concerns/cache_markdown_field_spec.rb

@@ -30,6 +30,10 @@ describe CacheMarkdownField, :clean_gitlab_redis_cache do
       def id
         "test-markdown-cache"
       end
+
+      def cache_key
+        "cache-key"
+      end
     end
   end