diff --git a/features/project/merge_requests.feature b/features/project/merge_requests.feature
index 80f0098..5b8becb 100644
--- a/features/project/merge_requests.feature
+++ b/features/project/merge_requests.feature
@@ -35,8 +35,34 @@ Feature: Project Merge Requests
     Then I should see merge request "Wiki Feature"
 
   @javascript
-  Scenario: I comment merge request
+  Scenario: I comment on a merge request
     Given I visit merge request page "Bug NS-04"
     And I leave a comment like "XML attached"
     Then I should see comment "XML attached"
 
+  @javascript
+  Scenario: I comment on a merge request diff
+    Given project "Shop" have "Bug NS-05" open merge request with diffs inside
+    And I visit merge request page "Bug NS-05"
+    And I switch to the diff tab
+    And I leave a comment like "Line is wrong" on line 185 of the first file
+    And I switch to the merge request's comments tab
+    Then I should see a discussion has started on line 185
+
+  @javascript
+  Scenario: I comment on a line of a commit in merge request
+    Given project "Shop" have "Bug NS-05" open merge request with diffs inside
+    And I visit merge request page "Bug NS-05"
+    And I click on the first commit in the merge request
+    And I leave a comment like "Line is wrong" on line 185 of the first file
+    And I switch to the merge request's comments tab
+    Then I should see a discussion has started on commit bcf03b5de6c:L185
+
+  @javascript
+  Scenario: I comment on a commit in merge request
+    Given project "Shop" have "Bug NS-05" open merge request with diffs inside
+    And I visit merge request page "Bug NS-05"
+    And I click on the first commit in the merge request
+    And I leave a comment on the diff page
+    And I switch to the merge request's comments tab
+    Then I should see a discussion has started on commit bcf03b5de6c
diff --git a/features/steps/project/project_merge_requests.rb b/features/steps/project/project_merge_requests.rb
index d153ad2..5248a5c 100644
--- a/features/steps/project/project_merge_requests.rb
+++ b/features/steps/project/project_merge_requests.rb
@@ -4,77 +4,148 @@ class ProjectMergeRequests < Spinach::FeatureSteps
   include SharedNote
   include SharedPaths
 
-  Then 'I should see "Bug NS-04" in merge requests' do
-    page.should have_content "Bug NS-04"
+  Given 'I click link "New Merge Request"' do
+    click_link "New Merge Request"
   end
 
-  And 'I should not see "Feature NS-03" in merge requests' do
-    page.should_not have_content "Feature NS-03"
+  Given 'I click link "Bug NS-04"' do
+    click_link "Bug NS-04"
+  end
+
+  Given 'I click link "All"' do
+    click_link "All"
   end
 
   Given 'I click link "Closed"' do
     click_link "Closed"
   end
 
-  Then 'I should see "Feature NS-03" in merge requests' do
-    page.should have_content "Feature NS-03"
+  Then 'I should see merge request "Wiki Feature"' do
+    page.should have_content "Wiki Feature"
   end
 
-  And 'I should not see "Bug NS-04" in merge requests' do
-    page.should_not have_content "Bug NS-04"
+  Then 'I should see closed merge request "Bug NS-04"' do
+    mr = MergeRequest.find_by_title("Bug NS-04")
+    mr.closed.should be_true
+    page.should have_content "Closed by"
   end
 
-  Given 'I click link "All"' do
-    click_link "All"
+  Then 'I should see merge request "Bug NS-04"' do
+    page.should have_content "Bug NS-04"
   end
 
-  Given 'I click link "Bug NS-04"' do
-    click_link "Bug NS-04"
+  Then 'I should see "Bug NS-04" in merge requests' do
+    page.should have_content "Bug NS-04"
   end
 
-  Then 'I should see merge request "Bug NS-04"' do
-    page.should have_content "Bug NS-04"
+  Then 'I should see "Feature NS-03" in merge requests' do
+    page.should have_content "Feature NS-03"
   end
 
-  And 'I click link "Close"' do
-    click_link "Close"
+  And 'I should not see "Feature NS-03" in merge requests' do
+    page.should_not have_content "Feature NS-03"
   end
 
-  Then 'I should see closed merge request "Bug NS-04"' do
-    mr = MergeRequest.find_by_title("Bug NS-04")
-    mr.closed.should be_true
-    page.should have_content "Closed by"
+
+  And 'I should not see "Bug NS-04" in merge requests' do
+    page.should_not have_content "Bug NS-04"
   end
 
-  Given 'I click link "New Merge Request"' do
-    click_link "New Merge Request"
+  And 'I click link "Close"' do
+    click_link "Close"
   end
 
   And 'I submit new merge request "Wiki Feature"' do
-    fill_in "merge_request_title", :with => "Wiki Feature"
-    select "master", :from => "merge_request_source_branch"
-    select "stable", :from => "merge_request_target_branch"
+    fill_in "merge_request_title", with: "Wiki Feature"
+    select "master", from: "merge_request_source_branch"
+    select "stable", from: "merge_request_target_branch"
     click_button "Save"
   end
 
-  Then 'I should see merge request "Wiki Feature"' do
-    page.should have_content "Wiki Feature"
-  end
-
   And 'project "Shop" have "Bug NS-04" open merge request' do
     project = Project.find_by_name("Shop")
     create(:merge_request,
-           :title => "Bug NS-04",
-           :project => project,
-           :author => project.users.first)
+           title: "Bug NS-04",
+           project: project,
+           author: project.users.first)
+  end
+
+  And 'project "Shop" have "Bug NS-05" open merge request with diffs inside' do
+    project = Project.find_by_name("Shop")
+    create(:merge_request_with_diffs,
+           title: "Bug NS-05",
+           project: project,
+           author: project.users.first)
   end
 
   And 'project "Shop" have "Feature NS-03" closed merge request' do
     project = Project.find_by_name("Shop")
     create(:merge_request,
-           :title => "Feature NS-03",
-           :project => project,
-           :author => project.users.first,
-           :closed => true)
+           title: "Feature NS-03",
+           project: project,
+           author: project.users.first,
+           closed: true)
+  end
+
+  And 'I switch to the diff tab' do
+    mr = MergeRequest.find_by_title("Bug NS-05")
+    visit diffs_project_merge_request_path(mr.project, mr)
+  end
+
+  And 'I switch to the merge request\'s comments tab' do
+    mr = MergeRequest.find_by_title("Bug NS-05")
+    visit project_merge_request_path(mr.project, mr)
+  end
+
+  And 'I click on the first commit in the merge request' do
+    mr = MergeRequest.find_by_title("Bug NS-05")
+    click_link mr.commits.first.short_id(8)
+  end
+
+  And 'I leave a comment on the diff page' do
+    within(:xpath, "//div[@class='note-form-holder']") do
+      fill_in "note_note", with: "One comment to rule them all"
+      click_button "Add Comment"
+    end
+  end
+
+  And 'I leave a comment like "Line is wrong" on line 185 of the first file' do
+    within(:xpath, "//div[@class='diff_file'][1]") do
+      click_link "add-diff-line-note-0_185_185"
+    end
+
+    within(:xpath, "//div[@class='line-note-form-holder']") do
+      fill_in "note_note", with: "Line is wrong"
+      click_button "Add Comment"
+    end
+  end
+
+  Then 'I should see a discussion has started on line 185' do
+    mr = MergeRequest.find_by_title("Bug NS-05")
+    first_commit = mr.commits.first
+    first_diff   = mr.diffs.first
+    page.should have_content "#{current_user.name} started a discussion on this merge request diff"
+    page.should have_content "#{first_diff.b_path}:L185"
+    page.should have_content "Line is wrong"
+  end
+
+  Then 'I should see a discussion has started on commit bcf03b5de6c:L185' do
+    mr = MergeRequest.find_by_title("Bug NS-05")
+    first_commit = mr.commits.first
+    first_diff   = mr.diffs.first
+    page.should have_content "#{current_user.name} started a discussion on commit"
+    page.should have_content first_commit.short_id(8)
+    page.should have_content "#{first_diff.b_path}:L185"
+    page.should have_content "Line is wrong"
+  end
+
+  Then 'I should see a discussion has started on commit bcf03b5de6c' do
+    mr = MergeRequest.find_by_title("Bug NS-05")
+    first_commit = mr.st_commits.first
+    first_diff   = mr.diffs.first
+    page.should have_content "#{current_user.name} started a discussion on commit"
+    page.should have_content first_commit.short_id(8)
+    page.should have_content "One comment to rule them all"
+    page.should_not have_content "#{first_diff.b_path}:L185"
   end
 end
diff --git a/features/steps/shared/paths.rb b/features/steps/shared/paths.rb
index a125762..bf20d5f 100644
--- a/features/steps/shared/paths.rb
+++ b/features/steps/shared/paths.rb
@@ -215,6 +215,11 @@ module SharedPaths
     visit project_merge_request_path(mr.project, mr)
   end
 
+  Given 'I visit merge request page "Bug NS-05"' do
+    mr = MergeRequest.find_by_title("Bug NS-05")
+    visit project_merge_request_path(mr.project, mr)
+  end
+
   And 'I visit project "Shop" merge requests page' do
     visit project_merge_requests_path(Project.find_by_name("Shop"))
   end
--
libgit2 0.21.2