Problem#comments counter cache

Marcin Ciunelis
1 parent 695de2bb
Showing 6 changed files with 53 additions and 2 deletions Show diff stats
app/models/comment.rb
app/models/problem.rb
app/views/errs/_table.html.haml
db/migrate/20111019163257_add_problem_comments_count.rb
spec/factories/comment_factories.rb
spec/models/problem_spec.rb
@@ -2,12 +2,25 @@ class Comment
   include Mongoid::Document
   include Mongoid::Timestamps
  
+  after_create :increase_counter_cache
+  before_destroy :decrease_counter_cache
+
   field :body, :type => String
   index :user_id
  
-  belongs_to :err
+  belongs_to :err, :class_name => "Problem"
   belongs_to :user
  
   validates_presence_of :body
+
+  protected
+    def increase_counter_cache
+      err.inc(:comments_count, 1)
+    end
+
+    def decrease_counter_cache
+      err.inc(:comments_count, -1) if err
+    end
+
 end
  
@@ -21,6 +21,7 @@ class Problem
   field :user_agents, :type => Array, :default => []
   field :messages, :type => Array, :default => []
   field :hosts, :type => Array, :default => []
+  field :comments_count, :type => Integer, :default => 0
  
   index :app_id
   index :app_name
@@ -26,7 +26,7 @@
           %td.message
             = link_to trucated_err_message(problem), app_err_path(problem.app, problem)
             %em= problem.where
-            - if problem.comments.any?
+            - if problem.comments_count > 0
               - comment = problem.comments.last
               %br
               .inline_comment
@@ -0,0 +1,10 @@
+class AddProblemCommentsCount < Mongoid::Migration
+  def self.up
+    Problem.all.each do |problem|
+      problem.update_attributes(:comments_count => problem.comments.count)
+    end
+  end
+
+  def self.down
+  end
+end
 \ No newline at end of file
 Factory.define :comment do |c|
   c.user       {|u| u.association :user}
   c.body       'Test comment'
+  c.err        {|e| e.association :problem}
 end
  
@@ -276,5 +276,31 @@ describe Problem do
     end
   end
  
+  context "comment counter cache" do
+    before do
+      @app = Factory(:app)
+      @problem = Factory(:problem, :app => @app)
+    end
+
+    it "#comments_count returns 0 by default" do
+      @problem.comments_count.should == 0
+    end
+
+    it "adding a comment increases #comments_count by 1" do
+      lambda {
+        Factory(:comment, :err => @problem)
+      }.should change(@problem, :comments_count).from(0).to(1)
+    end
+
+    it "removing a comment decreases #comments_count by 1" do
+      comment1 = Factory(:comment, :err => @problem)
+      lambda {
+        @problem.reload.comments.first.destroy
+        @problem.reload
+      }.should change(@problem, :comments_count).from(1).to(0)
+    end
+  end
+
+
 end
...	...	@@ -2,12 +2,25 @@ class Comment
2	2	include Mongoid::Document
3	3	include Mongoid::Timestamps
4	4
	5	+ after_create :increase_counter_cache
	6	+ before_destroy :decrease_counter_cache
	7	+
5	8	field :body, :type => String
6	9	index :user_id
7	10
8		- belongs_to :err
	11	+ belongs_to :err, :class_name => "Problem"
9	12	belongs_to :user
10	13
11	14	validates_presence_of :body
	15	+
	16	+ protected
	17	+ def increase_counter_cache
	18	+ err.inc(:comments_count, 1)
	19	+ end
	20	+
	21	+ def decrease_counter_cache
	22	+ err.inc(:comments_count, -1) if err
	23	+ end
	24	+
12	25	end
13	26
...	...
...	...	@@ -21,6 +21,7 @@ class Problem
21	21	field :user_agents, :type => Array, :default => []
22	22	field :messages, :type => Array, :default => []
23	23	field :hosts, :type => Array, :default => []
	24	+ field :comments_count, :type => Integer, :default => 0
24	25
25	26	index :app_id
26	27	index :app_name
...	...
...	...	@@ -26,7 +26,7 @@
26	26	%td.message
27	27	= link_to trucated_err_message(problem), app_err_path(problem.app, problem)
28	28	%em= problem.where
29		- - if problem.comments.any?
	29	+ - if problem.comments_count > 0
30	30	- comment = problem.comments.last
31	31	%br
32	32	.inline_comment
...	...
...	...	@@ -0,0 +1,10 @@
	1	+class AddProblemCommentsCount < Mongoid::Migration
	2	+ def self.up
	3	+ Problem.all.each do \|problem\|
	4	+ problem.update_attributes(:comments_count => problem.comments.count)
	5	+ end
	6	+ end
	7	+
	8	+ def self.down
	9	+ end
	10	+end
0	11	\ No newline at end of file
...	...
1	1	Factory.define :comment do \|c\|
2	2	c.user {\|u\| u.association :user}
3	3	c.body 'Test comment'
	4	+ c.err {\|e\| e.association :problem}
4	5	end
5	6
...	...
...	...	@@ -276,5 +276,31 @@ describe Problem do
276	276	end
277	277	end
278	278
	279	+ context "comment counter cache" do
	280	+ before do
	281	+ @app = Factory(:app)
	282	+ @problem = Factory(:problem, :app => @app)
	283	+ end
	284	+
	285	+ it "#comments_count returns 0 by default" do
	286	+ @problem.comments_count.should == 0
	287	+ end
	288	+
	289	+ it "adding a comment increases #comments_count by 1" do
	290	+ lambda {
	291	+ Factory(:comment, :err => @problem)
	292	+ }.should change(@problem, :comments_count).from(0).to(1)
	293	+ end
	294	+
	295	+ it "removing a comment decreases #comments_count by 1" do
	296	+ comment1 = Factory(:comment, :err => @problem)
	297	+ lambda {
	298	+ @problem.reload.comments.first.destroy
	299	+ @problem.reload
	300	+ }.should change(@problem, :comments_count).from(1).to(0)
	301	+ end
	302	+ end
	303	+
	304	+
279	305	end
280	306
...	...